Submitted - SM_Report_98-17.pdf
", "abstract": "Classical dynamic fracture theories predict the Rayleigh surface wave speed to be the limiting speed for propagation of in-plane cracks in homogeneous, linear-elastic materials subjected to remote loading. However, in the present\nstudy, experimental evidence to the contrary is reported, in which intersonic shear dominated crack growth is seen along weak planes in Homalite-100 under far-field asymmetric loading. It is seen that mode-II (in-plane shear) conditions are essential to attain intersonic crack-tip speeds. The stress field generated by\nthe intersonically propagating crack-tip is recorded using photoelasticity and high speed photography. Intersonic shear cracks, featuring shear shock waves\nand large scale crack face frictional contact, are initially highly unstable and\ncrack-tip speeds vary from the shear wave speed to the dilatational wave speed of the material. As steady state conditions are achieved, the mode-II intersonic\ncracks propagate at a constant speed of \u221a2c_s. These observations have potential implications in geological settings where intersonic rupture velocities have been\nreported for crustal earthquakes.", "date": "1998-12", "date_type": "published", "publisher": "California Institute of Technology", "id_number": "CaltechAUTHORS:20151124-101329882", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151124-101329882", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "CMS-9424113" }, { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-95-0453" } ] }, "other_numbering_system": { "items": [ { "id": "98-17", "name": "GALCIT Report SM" } ] }, "local_group": { "items": [ { "id": "Graduate-Aeronautical-Laboratories-(Solid-Mechanics)" }, { "id": "GALCIT" } ] }, "doi": "10.7907/fcw8-1577", "primary_object": { "basename": "SM_Report_98-17.pdf", "url": "https://authors.library.caltech.edu/records/hfsy1-xhq05/files/SM_Report_98-17.pdf" }, "pub_year": "1998", "author_list": "Rosakis, A. J.; Samudrala, O.; et al." }, { "id": "https://authors.library.caltech.edu/records/bhtq6-m5c35", "eprint_id": 25645, "eprint_status": "archive", "datestamp": "2023-08-20 04:06:41", "lastmod": "2025-01-29 00:30:06", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Vendroux-G", "name": { "family": "Vendroux", "given": "G." } }, { "id": "Knauss-W-G", "name": { "family": "Knauss", "given": "W. G." } } ] }, "title": "Deformation Measurements at the Sub-Micron Size Scale: II. Refinements in the Algorithm for Digital Image Correction", "ispublished": "unpub", "full_text_status": "public", "note": "This work has been supported by the National Science Foundation under grant MSS 9109973 for the hardware component of the STM. Also additional assistance through the Office of Naval Research (grant N00014-91-5-1427) and the Albert and Marguerite Ramond fellowship is gratefully acknowledged. In addition, the authors wish to thank H. Lu, graduate student, for his help in providing some of the experimental data.", "abstract": "Improvements are proposed in the application of the Digital Image Correlation method, a technique that compares digital images of a specimen surface before and after deformation to deduce its sureface (2-D) displacement field and strains. These refinements, tested on translations and rigid body rotations were significant with regard to the computer efficiency and covergence properties of the method. In addition, the formulation of the algorithm was extended so as to compute the three-dimensional surface displacement field from Scanning Tunneling Microscope tomographies of a deforming specimen. The reolsution of this new displacement measuring method at the namometer scale was assessed on translation and uniaxial tensile tests and was found to be 4.8 nm for in-plane displacement components and 1.5 nm for the out-of-plane one spanning a 10 x 10 \u03bcm area.", "date": "1994-04", "date_type": "published", "publisher": "California Institute of Technology", "id_number": "CaltechGALCITSM:GALCITSM94-5", "official_url": "https://resolver.caltech.edu/CaltechGALCITSM:GALCITSM94-5", "rights": "You are granted permission for individual, educational, research and non-commercial reproduction, distribution, display and performance of this work in any format.", "other_numbering_system": { "items": [ { "id": "94-5", "name": "GALCIT Report SM" } ] }, "local_group": { "items": [ { "id": "Graduate-Aeronautical-Laboratories-(Solid-Mechanics)" }, { "id": "GALCIT" } ] }, "doi": "10.7907/pedw-pd07", "primary_object": { "basename": "SM94-5.pdf", "url": "https://authors.library.caltech.edu/records/bhtq6-m5c35/files/SM94-5.pdf" }, "pub_year": "1994", "author_list": "Vendroux, G. and Knauss, W. G." }, { "id": "https://authors.library.caltech.edu/records/2s6rf-q1x14", "eprint_id": 417, "eprint_status": "archive", "datestamp": "2023-08-22 09:39:57", "lastmod": "2025-01-29 00:25:51", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Vendroux-G", "name": { "family": "Vendroux", "given": "G." } }, { "id": "Knauss-W-G", "name": { "family": "Knauss", "given": "W. G." } } ] }, "title": "Submicron Deformation Field Measurements II: Improved Digital Image Correlation", "ispublished": "unpub", "full_text_status": "public", "note": "This work has been supported by the National Science Foundation under grant MSS 9109973 for the hardware component of the STM. Also substantial assistance through the Office of Naval Research (grant N00014-91-5-1427), with Dr. Peter Schmidt as the monitor, and through support via Albert and Marguerite Ramond fellowships is gratefully acknowledged. In addition, the authors wish to thank H. Lu, graduate student, for his help in providing some of the experimental speckle/CCD data.", "abstract": "This is the second paper in a series of three devoted to the applicaiton of Scanning Tunneling Microscopy to mechanics problems. In this paper improvements to the Digital Image Correlation method are outlined, a technique that compares digital images of a specimen surface before and after deformation to deduce its (2-D) surface displacement field and strains. The necessity of using the framework of large deformation theory for accurately addressing rigid body rotations to reduce associated errors in the strain components is pointed out. In addition, the algorithm is extended to compute the three-dimensional surface displacement field from Scanning Tunneling Microscope data; also, significant improvements are achieved in the rate as well as the robustness of the convergence. For Scanning Tunneling Microscopy topographs the resolution yields 4.8 nm\nfor the in-plane and 1.5 nm for the out-of-plane displacement components spanning an area of 10 \u03bcm x 10 \u03bcm.", "date": "1994", "date_type": "published", "publisher": "California Institute of Technology", "id_number": "CaltechAUTHORS:GALCITSM94-5a", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:GALCITSM94-5a", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "MSS 9109973" }, { "agency": "Office of Naval Research", "grant_number": "N00014-91-5-1427" }, { "agency": "Albert and Marguerite Ramond Fellowships" } ] }, "other_numbering_system": { "items": [ { "id": "94-5a", "name": "GALCIT Report SM" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Graduate-Aeronautical-Laboratories-(Solid-Mechanics)" } ] }, "doi": "10.7907/zvy1-mb79", "primary_object": { "basename": "SM94-5a.pdf", "url": "https://authors.library.caltech.edu/records/2s6rf-q1x14/files/SM94-5a.pdf" }, "pub_year": "1994", "author_list": "Vendroux, G. and Knauss, W. G." }, { "id": "https://authors.library.caltech.edu/records/dbngb-qns67", "eprint_id": 55145, "eprint_status": "archive", "datestamp": "2023-08-20 02:07:56", "lastmod": "2025-01-30 04:01:13", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "G." }, "orcid": "0000-0002-2912-0001" }, { "id": "Tong-W", "name": { "family": "Tong", "given": "W." } } ] }, "title": "Effective Elastic Moduli and Characterization of a Particulate-Reinforced Metal Matrix Composite with Damaged Particles", "ispublished": "unpub", "full_text_status": "public", "note": "The authors would like to acknowledge the support of this research by the Division of Materials Research of the National Science Foundation through grant #DMR-9116570. G.R. acknowledges the support of an NSF Presidential Young Investigator award, grant #MSS-9157846.\n\nSubmitted - Effective_Elastic_moduli_And_Characterrization_of_A_part.pdf
", "abstract": "A brief derivation of the expression is given for the effective bulk modulus of discontinuously\nreinforced metal matrix composites (DMMCs) with damaged particles (either complete voids\nas shattered particles or debonded particles). The analytical results are then compared with\nelastic moduli determined from nondestructive ultrasonic wave speed measurements of SiC\nparticle-reinforced titanium matrix composites produced via shock wave consolidation. For\nthe shock consolidated Ti-SiC metal matrix composites compacts, the overall particle damage\nmode is found to be similar to debonded particles and the effective volume fraction of\ndamaged particles is determined to be 39% based on the data of both Young's and bulk\nmoduli. Ultrasonic wave speed measurements combining with analytical and/or numerical\nresults on overall elastic properties (Young's, bulk, and shear moduli, and Poisson's ratio)\ncould be a useful tool in assessing the damage of particles in DMMCs.", "date": "1993", "date_type": "published", "publisher": "California Institute of Technology", "id_number": "CaltechAUTHORS:20150224-095122748", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150224-095122748", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "DMR-9116570" }, { "agency": "NSF", "grant_number": "MSS-9157846" } ] }, "other_numbering_system": { "items": [ { "id": "93-31", "name": "GALCIT Report SM" } ] }, "local_group": { "items": [ { "id": "Graduate-Aeronautical-Laboratories-(Solid-Mechanics)" }, { "id": "GALCIT" } ] }, "doi": "10.7907/9ad7-d717", "primary_object": { "basename": "Effective_Elastic_moduli_And_Characterrization_of_A_part.pdf", "url": "https://authors.library.caltech.edu/records/dbngb-qns67/files/Effective_Elastic_moduli_And_Characterrization_of_A_part.pdf" }, "pub_year": "1993", "author_list": "Ravichandran, G. and Tong, W." }, { "id": "https://authors.library.caltech.edu/records/rz0hf-4v226", "eprint_id": 55628, "eprint_status": "archive", "datestamp": "2023-08-20 00:48:10", "lastmod": "2025-01-30 04:01:47", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Rosakis-A-J", "name": { "family": "Rosakis", "given": "A. J." }, "orcid": "0000-0003-0559-0794" }, { "id": "Mason-J-J", "name": { "family": "Mason", "given": "J. J." } }, { "id": "Ravichandran-G", "name": { "family": "Ravichandran", "given": "G." }, "orcid": "0000-0002-2912-0001" } ] }, "title": "The Conversion of Plastic Work to Heat around a Dynamically Propagating Crack in Metals", "ispublished": "unpub", "full_text_status": "public", "note": "We are grateful to Office of Naval Research for support under grant N00014-90-J-1340 and to A.T. Zehnder for sharing the raw data from his investigation. The computations described here were carried out on a Cray Y-MP at the San Diego Supercomputing Center (SDSC).\n\nSubmitted - ADA253801.pdf
", "abstract": "Investigations of the temperature rise at a dynamically propagating crack tip using an infrared detector array are reported. Also, a measurement of the fraction of plastic work converted to heat using a split hopkinson bar apparatus in conjunction with an infrared detector array is summarized. For 4340 steel it is seen that \u224885% of the plastic work is converted to heat leading to a temperature rise of 300\u00b0C at a crack tip propagating 600 m/s in steel. This results is compared to earlier studies that report a 450\u00b0C temperature rise at a crack tip propagating 900 m/s in steel. In a titanium alloy the temperature rise is higher than that in steel for equal plastic work rate densities. The conditions at the crack tip are shown to be adiabatic, and, as a result, this effect is due to the difference in density, heat capacity and crack tip speed. Thermal conductivity has no effect.", "date": "1992", "date_type": "published", "publisher": "California Institute of Technology", "id_number": "CaltechAUTHORS:20150309-093637326", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150309-093637326", "rights": "You are granted permission for individual, educational, research and non-commercial reproduction, distribution, display and performance of this work in any format.", "funders": { "items": [ { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-90-J-1340" } ] }, "other_numbering_system": { "items": [ { "id": "92-17", "name": "GALCIT Report SM" } ] }, "local_group": { "items": [ { "id": "Graduate-Aeronautical-Laboratories-(Solid-Mechanics)" }, { "id": "GALCIT" } ] }, "doi": "10.7907/f9vk-b551", "primary_object": { "basename": "ADA253801.pdf", "url": "https://authors.library.caltech.edu/records/rz0hf-4v226/files/ADA253801.pdf" }, "pub_year": "1992", "author_list": "Rosakis, A. J.; Mason, J. J.; et al." }, { "id": "https://authors.library.caltech.edu/records/4vxp2-b1x37", "eprint_id": 25643, "eprint_status": "archive", "datestamp": "2023-08-19 13:20:34", "lastmod": "2025-01-29 00:29:56", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Knauss-W-G", "name": { "family": "Knauss", "given": "W. G." } } ] }, "title": "Hygroviscoelasticity of the Human Intervertebral Disc: Final Report", "ispublished": "unpub", "full_text_status": "public", "note": "Final Report to the Air Force Office of Scientific Research.\n\nThe authors are indebted to Professors P. Harvey and M. Patzakis of the Orthopedics Department at USC County Medical School for continued guidance and discussions. This work was supported by the directorate of Life Sciences of the Air Force Office of Scientific Research under Lt. Col. D. Maio and parallels work done under Dr. L. Kazarian of the Biodynamics and Bioengineering Division of the Wright-Patterson Air Force Base.", "abstract": "In order to gain an improved understanding of the behavior of human intervertebral disc material under various kinds of loads the viscoelastic properties of small specimens excised from human L4-L5 discs were examined. Excisions were made from donated spine segments procured a few hours after death and then frozen. Material examined was in the form of single lamellar specimens as well as specimens containing several lamellae. \n\nTensile relaxation tests were performed on single lamellae prepared such that the collagen fibers were a) aligned with the tension axis, b) normal to the tension axis and c) at an angle of about 30[degrees] with that axis. The multi-lamellar specimens were excised from the disc such that one set produced the tensile axis to run parallel to the disc circumference (surrounding the spinal axis) while another set caused the tensile axis to run parallel to the spinal axis. \n\nIt was found early in the study that the water content of the disc material has a profound effect on its mechanical response. Consequently the diffusion and swelling characteristics of the material in different water environments were studied. Primarily air of differing relative humidity and various concentrated solutions of NaCl were used to provide for different water concentrations in the material. \n\nFor the relaxation studies the same environments were used. This allowed achieving water concentrations ranging from virtually dry to in-vivo conditions. \n\nThe main findings of this work are: \n\n1) Water affects the relaxation time in a sensitive way. A few percent change in water content can change the relaxation time by an order of magnitude or more. This fact is important when one is concerned with laboratory testing without being able to control the water content at all times. \n\n2) Diffusion is a surprisingly slow process taking place over several hours (2-3) in specimens only 1/2 mm thick. The\namount of water take-up is controlled by the environment (distilled water destroys samples into fissures) and by constraints offered by the fiber structure and the stresses it engenders (see point 5) below). \n\n3) The stiffness of the disc material is on the order of 3 to 10 x 10^-6 N/m^2; relaxation occuring, on the whole rather slowly, i.e., on the order of 10% per decade. The relaxation modulus at right angles to the collagen fibers is about 1/3 that of the modulus along the fiber direction. \n\n4) The relaxation modulus of multi-layer specimens cut from the disc in a circumferential and a spine-axial direction are very nearly the same; the modulus for the circumferential material is slightly higher. The consequence of this would be that although one would expect a markedly anisotropic behavior of the disc material on the basis of its fiber and lamellar construction, the disc material does not deviate very strongly from isotropic response. (Isotropy as-referred to a plane that is tangent to the disc perimetric surface.) \n\n5) Stress affects the equilibrium concentration of water in the material. The implication - and test result - is that once the stress has changed the equilibrium of water content with the environment is disturbed and the concentration changes. That change, in turn, causes a change in relaxation behavior such that tensile stresses cause an acceleration of relaxation or creep (softening), while compression would cause the opposite affect (hardening). The material responds thus to stress as a system that is open to the environment.", "date": "1980-07", "date_type": "published", "publisher": "California Institute of Technology", "id_number": "CaltechGALCITSM:GALCITSM80-18", "official_url": "https://resolver.caltech.edu/CaltechGALCITSM:GALCITSM80-18", "rights": "You are granted permission for individual, educational, research and non-commercial reproduction, distribution, display and performance of this work in any format.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)" } ] }, "other_numbering_system": { "items": [ { "id": "80-18", "name": "GALCIT Report SM" } ] }, "local_group": { "items": [ { "id": "Graduate-Aeronautical-Laboratories-(Solid-Mechanics)" }, { "id": "GALCIT" } ] }, "doi": "10.7907/qx6y-c525", "primary_object": { "basename": "SM_80-18.pdf", "url": "https://authors.library.caltech.edu/records/4vxp2-b1x37/files/SM_80-18.pdf" }, "pub_year": "1980", "author_list": "Knauss, W. G." }, { "id": "https://authors.library.caltech.edu/records/6p33b-x9e56", "eprint_id": 51783, "eprint_status": "archive", "datestamp": "2023-08-19 12:45:25", "lastmod": "2025-01-30 03:59:58", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Chai-H", "name": { "family": "Chai", "given": "H." } }, { "id": "Babcock-C-D", "name": { "family": "Babcock", "given": "C. D." } }, { "id": "Knauss-W-G", "name": { "family": "Knauss", "given": "W. G." } } ] }, "title": "The Incorporation of Bending into the Buckling Delamination Analysis: Informal Progress Report No. 3", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a91979 California Institute of Technology.\n\nInformal Progress Report No. 3\n\nSubmitted - SM_79-15.pdf
", "abstract": "In a previous report a one dimensional model of buckling-delamination in a column was summarized. The main assumption made in that report was that the unbuckled portions of the column can be assumed to remain straight. The purpose of this report is to investigate the\nmore general problem in which bending effects are taken into account. We deal here with the case of a single off center delamination in a column. (The case of multi-delaminations in a column can be worked out too\nunder slight modifications.) Following the general procedure outlined in previous reports, consider the column of unit width shown in fig, la, State I represents the unstressed column while state I1 denotes the\naxially and uniformally compressed column. State III differs from II by allowing the delamination to buckle. Our aim here is to find an\nexpression for the strain energy release rate of state III.", "date": "1979-11", "date_type": "published", "publisher": "California Institute of Technology", "id_number": "CaltechAUTHORS:20141114-131259517", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141114-131259517", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "79-15", "name": "GALCIT Report SM" } ] }, "local_group": { "items": [ { "id": "Graduate-Aeronautical-Laboratories-(Solid-Mechanics)" }, { "id": "GALCIT" } ] }, "doi": "10.7907/jvgn-3580", "primary_object": { "basename": "SM_79-15.pdf", "url": "https://authors.library.caltech.edu/records/6p33b-x9e56/files/SM_79-15.pdf" }, "pub_year": "1979", "author_list": "Chai, H.; Babcock, C. D.; et al." }, { "id": "https://authors.library.caltech.edu/records/3c3ef-57s65", "eprint_id": 25644, "eprint_status": "archive", "datestamp": "2023-08-19 10:44:17", "lastmod": "2025-01-29 00:29:58", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Panagiotacopulos-N-D", "name": { "family": "Panagiotacopulos", "given": "N. D." } }, { "id": "Bloch-R", "name": { "family": "Bloch", "given": "R." } }, { "id": "Knauss-W-G", "name": { "family": "Knauss", "given": "W. G." } }, { "id": "Harvey-P", "name": { "family": "Harvey", "given": "P." } }, { "id": "Patzakis-M", "name": { "family": "Patzakis", "given": "M." } } ] }, "title": "Viscoelastic Behavior of the Human Intervertebral Disc Under Consideration of Moisture Migration", "ispublished": "unpub", "full_text_status": "public", "note": "(Interim Progress Report).\nAir Force Office of Scientific Research Grant No. 77-3139.", "abstract": "The human intervertebral disc is a highly inhomogeneous fiber composite pressure vessel. If damaged in the post-infant stage, the disc does not repair and may need surgical correction. Diagnosis of whether a disc is damaged is difficult at best and, at this time, involves invasive techniques which are not free of danger (injection of x-ray opaque liquids). Starting from a desire to develop a noninvasive diagnostic technique based on x-ray and computer aided image enhancement, we became interested in the mechanical properties of the disc. These would be important in gaging the x-ray detected deformations of the disc under various loads. During the course of this work we became aware of another need of diagnostics related to estimating the proclivity of an intact disc to sustain damage under unusual loads. It turns out that the water content of the disc material dominates its mechanical behavior. Since modern medical equipment such as the EMI-x-ray body-scanner may record quantitatively the water content of the internal body organs, the possibility exists to gage in-vivo water content measurements with the mechanical performance of discs. \n\nBecause the layers of the disc's annulus fibrosous are so thin, we have had difficulty in preparing single-layer specimens. So far, we have worked mainly with three-layer specimens. That test geometry has been sufficient to establish several important aspects of the mechanical properties. \n\nWe find that the relaxation behavior is very sensitive to moisture content. Accordingly we have worked with carefully controlled environments including saline solutions claimed to represent body conditions. A major difficulty in obtaining repeatable results is obtaining straight test specimens and holding them in the clamps of the testing apparatus. If moisture and temperature conditioning was repeated without reclamping the specimen, reasonably repeatable results were obtained. No aging was observed after repeated drying and moisturizing cycles. \n\nWe also found that water diffuses slowly in the layers. The water apparently acts similar to the solvent in a polymer, effecting a change in the relaxation times. Increasing water content causes shortening of relaxation times, drying having the opposite effect. Upon controlling the water content of the specimen we are thus able to measure the relaxation behavior in various time domains. Data covering a wide spectrum of relaxation times is presented which includes all of the time scales experienced by the human body. This mechanical characterization gives us an estimate of how discs respond to different rates of deformation and loading conditions. \n\nIt is of interest to note that with age (past age 30) the moisture content of the human disc decreases (possible other changes involving increased cross-link density of the mucopolysaccharides as well as an exchange of mucopolysaccharides for collagen). As a result one would expect the human intervertebral disc to react more stiffly with increasing age under nearly constant speeds of motion. Combining this observation with the changes in the vigor of motion/muscle activity as a function of age allows a tentative explanation of the statistic that the largest incidence of disc problems occur around age 40-50.", "date": "1977-06-27", "date_type": "published", "publisher": "California Institute of Technology", "id_number": "CaltechGALCITSM:GALCITSM77afosr77-3139", "official_url": "https://resolver.caltech.edu/CaltechGALCITSM:GALCITSM77afosr77-3139", "rights": "You are granted permission for individual, educational, research and non-commercial reproduction, distribution, display and performance of this work in any format.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research", "grant_number": "77-3139" } ] }, "local_group": { "items": [ { "id": "Graduate-Aeronautical-Laboratories-(Solid-Mechanics)" }, { "id": "GALCIT" } ] }, "doi": "10.7907/ynhb-7j56", "primary_object": { "basename": "Grantno77-3139.pdf", "url": "https://authors.library.caltech.edu/records/3c3ef-57s65/files/Grantno77-3139.pdf" }, "pub_year": "1977", "author_list": "Panagiotacopulos, N. D.; Bloch, R.; et al." }, { "id": "https://authors.library.caltech.edu/records/t05qg-20918", "eprint_id": 50415, "eprint_status": "archive", "datestamp": "2023-08-19 08:55:31", "lastmod": "2025-01-30 03:50:05", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Arbocz-J", "name": { "family": "Arbocz", "given": "J." } }, { "id": "Babcock-C-D", "name": { "family": "Babcock", "given": "C. D." } } ] }, "title": "A Multimode Analysis for Calculating Buckling Loads of Imperfect Cylindrical Shells", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 1974 California Institute of Technology.\n\nC.I.T. SM 74-4.\n\nFirestone Flight Sciences Laboratory, Guggenheim Aeronautical Laboratory, Karman Laboratory of Fluid Mechanics and Jet Propulsion.\n\nThis work was supported by the National Science Foundation under Grant GK 16934.\n\nSubmitted - A_multimode_Analysis_for_calculating_buckling_loads_of_---1974.pdf
", "abstract": "By expanding the response of a cylindrical shell in truncated Fourier series, the nonlinear Donnell type shell equations for imperfect stiffened shells were reduced to a set of linear equations in the correction terms by Newton's method of quasilinearization. Solutions\nwere obtained for isotropic and for ring and stringer stiffened shells. The amplitudes of the initial imperfections used in the analysis were\ncalculated from the corresponding Imbert-Donnell imperfection models. The free parameters in this imperfection model were obtained by\nleast square fitting the harmonics of the experimentally measured initial imperfections. It was possible in all cases to achieve satisfactory correlation using only a few suitably chosen deflection and imperfection modes.", "date": "1974-06", "date_type": "published", "publisher": "California Institute of Technology", "id_number": "CaltechAUTHORS:20141015-140751753", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141015-140751753", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "GK 16934" } ] }, "other_numbering_system": { "items": [ { "id": "74-4", "name": "GALCIT Report SM" } ] }, "local_group": { "items": [ { "id": "Graduate-Aeronautical-Laboratories-(Solid-Mechanics)" }, { "id": "GALCIT" } ] }, "doi": "10.7907/fc4v-8284", "primary_object": { "basename": "A_multimode_Analysis_for_calculating_buckling_loads_of_---1974.pdf", "url": "https://authors.library.caltech.edu/records/t05qg-20918/files/A_multimode_Analysis_for_calculating_buckling_loads_of_---1974.pdf" }, "pub_year": "1974", "author_list": "Arbocz, J. and Babcock, C. D." }, { "id": "https://authors.library.caltech.edu/records/9e9d9-wwe03", "eprint_id": 53830, "eprint_status": "archive", "datestamp": "2023-08-19 05:04:26", "lastmod": "2025-01-30 04:00:36", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Chu-Billie", "name": { "family": "Chu", "given": "Billie" } } ] }, "title": "On the role of large elastic deformation in fracture initiation -- the cases of plane stress and plane strain", "ispublished": "unpub", "full_text_status": "public", "note": "The writer wishes to thank Professor M. L. Williams for his guidance in carrying out the work reported herein.\n\nSubmitted - GACLCIT-SM-65-21.pdf
", "abstract": "In recent years there has been an increase in interest in the problems of strength and deformation of highly elastic materials. A number of simpler cases which have been solved indicate some markedly different characteristics from their counterparts in infinitesimal elasticity. References 1 and 2 discuss these cases in some detail. It seems natural therefore to ask whether in the problem areas of fracture in which the application of the infinitesimal theory of elasticity has met with some success in brittle elastic materials an equally marked difference in behavior would result if the possibility of large strains were included in the analyses. \n\nThe question is more easily asked than answered since the inclusion of the possibility of large strains often complicates the problem mathematically many fold. Only recently, Williams and Schapery considered large strains in the instability analysis of the spherical cavity. One of their conclusions is that the strain at the cavity increases without bound as the cavity becomes vanishingly small, at a finite critical tensile loading at some large radius. The results of Williams and Schapery thus reinforce the suspicion held by many that large strain would play an important role in the study of fracture mechanics of highly elastic materials. \n\nThe present paper is devoted to the analogous problem of a plane sheet containing a circular hole while at some large radius an axially symmetric tensile loading p per unit length of the stretched boundary is applied. Notations of references 2 and 3 will be generally adopted and, their explanations will be provided whenever necessary for clarity.", "date": "1965-08", "date_type": "published", "publisher": "California Institute of Technology", "id_number": "CaltechAUTHORS:20150116-121251291", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150116-121251291", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "other_numbering_system": { "items": [ { "id": "65-21", "name": "GALCIT Report SM" } ] }, "local_group": { "items": [ { "id": "Graduate-Aeronautical-Laboratories-(Solid-Mechanics)" }, { "id": "GALCIT" } ] }, "doi": "10.7907/rhgg-hb35", "primary_object": { "basename": "GACLCIT-SM-65-21.pdf", "url": "https://authors.library.caltech.edu/records/9e9d9-wwe03/files/GACLCIT-SM-65-21.pdf" }, "pub_year": "1965", "author_list": "Chu, Billie" }, { "id": "https://authors.library.caltech.edu/records/0yere-m2y28", "eprint_id": 50402, "eprint_status": "archive", "datestamp": "2023-08-19 04:36:47", "lastmod": "2025-01-30 03:50:03", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ko-W-L", "name": { "family": "Ko", "given": "W. L." } }, { "id": "Blatz-P-J", "name": { "family": "Blatz", "given": "P. J." } } ] }, "title": "Application of Finite Viscoelastic Theory to the Deformation of Rubberlike Materials I. Uniaxial Stress Relaxation Data", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 1964 California Institute of Technology.\n\nThis research was supported by the National Aeronautics and Space Administration Research Grant No. NsG 172-60 - Supplement 1-62. GALCIT 120.\n\nSubmitted - Application_of_Finite_Viscoelastic_Theory_to_the....pdf
", "abstract": "In this report the constitutive equation for finite viscoelastic materials will be postulated as the sum of equilibrium terms and integral terms which describe the viscoelastic behavior of the materials and vanish when the equilibrium state is reached or when the materials have\nalways been at rest. It is also our purpose i) to show how the twelve relaxation functions are reduced to two independent ones in the case that\nthe material has Mooney-Rivlin elastic behavior and that all the relaxation functions depend only on time, ii) to display the mechanics of evaluating the two non-zero relaxation functions from data obtained from uniaxial\nstress relaxation tests.", "date": "1964-01", "date_type": "published", "publisher": "California Institute of Technology", "id_number": "CaltechAUTHORS:20141015-104600512", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141015-104600512", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA", "grant_number": "NsG 172-60" } ] }, "other_numbering_system": { "items": [ { "id": "120", "name": "GALCIT Report" } ] }, "local_group": { "items": [ { "id": "Graduate-Aeronautical-Laboratories-(Solid-Mechanics)" }, { "id": "GALCIT" } ] }, "doi": "10.7907/jt41-1v03", "primary_object": { "basename": "Application_of_Finite_Viscoelastic_Theory_to_the....pdf", "url": "https://authors.library.caltech.edu/records/0yere-m2y28/files/Application_of_Finite_Viscoelastic_Theory_to_the....pdf" }, "pub_year": "1964", "author_list": "Ko, W. L. and Blatz, P. J." }, { "id": "https://authors.library.caltech.edu/records/yk5gg-rfh60", "eprint_id": 62588, "eprint_status": "archive", "datestamp": "2023-08-19 04:01:45", "lastmod": "2025-01-30 04:10:44", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Blatz-P-J", "name": { "family": "Blatz", "given": "P. J." } }, { "id": "Ko-W-L", "name": { "family": "Ko", "given": "W. L." } }, { "id": "Zak-A-R", "name": { "family": "Zak", "given": "A. R." } } ] }, "title": "Fundamental Studies Relating to the Mechanical Behavior of Solid Propellants, Rocket Grains and Rocket Motors", "ispublished": "unpub", "full_text_status": "public", "note": "GALCIT 118 A - Progress Report No. 3 Aerojet Contract S-4200061-OP November 28, 1961 - February 28, 1962.\n\nThis program is being supported by the Aerojet-General Corporation, Sacramento Division, under technical cognizance of Dr. F. J. Climent to provide technical support to the Polaris Project.\n\nSubmitted - Fundamental_Studies_Relating_to_the_Mechanical_Behavior_of_Solid_Propellants.pdf
", "abstract": "The former reports provided considerable information about\nfoam and continuum rubbers under three types of tensile loading (i.e. uniaxial, strip-biaxial and homogeneous-biaxial tension). \n\nSince continuum rubbers are almost incompressible it is\nextremely difficult to determine the strain energy function beyond the linear term. On the other hand the highly dilatable foam rubber enables one to determine the functional form of the strain energy valid up to higher order terms. Special attention is being paid to foam rubber, since it represents .the limiting case of completely\ndewetted propellant.\n\nThe present report will (i) furnish the method of determination of strain energy function and the associated constitutive stress-strain law for large deformations out to fracture and (ii) present the triaxial tensile test data needed to double check item (i).", "date": "1962-02", "date_type": "published", "publisher": "California Institute of Technology", "id_number": "CaltechAUTHORS:20151203-152918001", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151203-152918001", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Aerojet-General Corporation", "grant_number": "S-4200061-OP" } ] }, "other_numbering_system": { "items": [ { "id": "62-14", "name": "GALCIT Report SM" } ] }, "local_group": { "items": [ { "id": "Graduate-Aeronautical-Laboratories-(Solid-Mechanics)" }, { "id": "GALCIT" } ] }, "doi": "10.7907/exmn-em08", "primary_object": { "basename": "Fundamental_Studies_Relating_to_the_Mechanical_Behavior_of_Solid_Propellants.pdf", "url": "https://authors.library.caltech.edu/records/yk5gg-rfh60/files/Fundamental_Studies_Relating_to_the_Mechanical_Behavior_of_Solid_Propellants.pdf" }, "pub_year": "1962", "author_list": "Blatz, P. J.; Ko, W. L.; et al." }, { "id": "https://authors.library.caltech.edu/records/zn3mx-jvd54", "eprint_id": 51778, "eprint_status": "archive", "datestamp": "2023-08-19 04:01:34", "lastmod": "2025-01-30 03:59:56", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Schapery-R-A", "name": { "family": "Schapery", "given": "R. A." } } ] }, "title": "A Simple Collocation Method for Fitting Viscoelastic Models to Experimental Data", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 1962 California Institute of Technology.\n\nNovember 1961, Revised February 1962.\n\nThis research was supported by the Aeronautical Research Laboratory Office of Aerospace Research United States Air Force Contract No. AF 33(616)-8399, GALCIT 119.\n\nSubmitted - SM_61-23A.pdf
", "abstract": "An easily applied collocation method is discussed for fitting the response of finite-element viscoelastic models to experimental stress-strain curves. It can be used with creep, relaxation, and steady-state oscillation data. The method is illustrated by means of two examples. As the first one, a model is obtained utilizing the dynamic shear compliance of polyisobutylene. In the second example we calculate a model from the tensile relaxation modulus of polymethyl methacrylate. With each case the model's response agreed with the experimental data within graphical accuracy over the entire frequency (or time) scale.", "date": "1962-02", "date_type": "published", "publisher": "California Institute of Technology", "id_number": "CaltechAUTHORS:20141114-115330896", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141114-115330896", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "AF 33(616)-8399" } ] }, "other_numbering_system": { "items": [ { "id": "61-23A", "name": "GALCIT Report SM" } ] }, "local_group": { "items": [ { "id": "Graduate-Aeronautical-Laboratories-(Solid-Mechanics)" }, { "id": "GALCIT" } ] }, "doi": "10.7907/92j7-g843", "primary_object": { "basename": "SM_61-23A.pdf", "url": "https://authors.library.caltech.edu/records/zn3mx-jvd54/files/SM_61-23A.pdf" }, "pub_year": "1962", "author_list": "Schapery, R. A." }, { "id": "https://authors.library.caltech.edu/records/wqg0c-vsv06", "eprint_id": 62059, "eprint_status": "archive", "datestamp": "2023-08-19 03:59:08", "lastmod": "2025-01-30 04:09:22", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Blatz-P-J", "name": { "family": "Blatz", "given": "P. J." } }, { "id": "Levinson-M", "name": { "family": "Levinson", "given": "M." } } ] }, "title": "Stress Induced Anisotropy in Pressurized Thick Walled Cylinders", "ispublished": "unpub", "full_text_status": "public", "note": "This research was supported by National Aeronautics and Space Administration Research Grant No. NsG-172-60.\n\nSubmitted - GALCIT_SM_62-6.pdf
", "abstract": "The most important mechanical features of propellants arise\nfrom the presence of a highly packed array of granular particles (filler), and a distribution of adhesive strengths between the rubbery binder and these particles. The first factor leads to dilatation and the formation of voids in any stress field other than pure hydrostatic compression. The second factor virtually guarantees that the pullaway of the binder from the filler is nonuniform, leading in extreme cases to the so-called \"zebra-stripe\" effect, or localized dewetting. This factor also is associated with stress relaxation due to the slow flow of the binder from regions of high strain concentration into regions of low concentration or into voids. Finally, because the binder is incompressible, and the filler is for all practical purposes infinitely rigid, most of the macroscopically applied load is concentrated as large strains near the binder-filler interfaces leading to non-linear behavior. At ambient temperature or thereabouts,\nviscoelasticity as associated with polymer chain uncoiling plays no role in the mechanical behavior of the propellant. Summarizing, the important mechanical features to be expected are \n\n1. Dilatation with void formation when the stress is tensile.\n\n2. Localized dilatation because of nonuniformity of adhesion\nstrengths.\n\n3. Stress relaxation due to binder flow and perhaps due to\nparticle movement at a very slow rate determined by frictional and adhesive effects .\n\n4. Nonlinear stress-strain relations due to high local strains at binder-filler interfaces.", "date": "1962-01", "date_type": "published", "publisher": "California Institute of Technology", "id_number": "CaltechAUTHORS:20151111-140758116", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151111-140758116", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA", "grant_number": "NsG-172-60" } ] }, "other_numbering_system": { "items": [ { "id": "62-6", "name": "GALCIT Report SM" } ] }, "local_group": { "items": [ { "id": "Graduate-Aeronautical-Laboratories-(Solid-Mechanics)" }, { "id": "GALCIT" } ] }, "doi": "10.7907/25x3-0y40", "primary_object": { "basename": "GALCIT_SM_62-6.pdf", "url": "https://authors.library.caltech.edu/records/wqg0c-vsv06/files/GALCIT_SM_62-6.pdf" }, "pub_year": "1962", "author_list": "Blatz, P. J. and Levinson, M." }, { "id": "https://authors.library.caltech.edu/records/0dj70-xne88", "eprint_id": 44715, "eprint_status": "archive", "datestamp": "2023-08-19 03:58:56", "lastmod": "2025-01-30 03:36:01", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Zak-A-R", "name": { "family": "Zak", "given": "A. R." } }, { "id": "Williams-M-L", "name": { "family": "Williams", "given": "M. L." } } ] }, "title": "Crack point stress singularities at a bi-material interface", "ispublished": "unpub", "full_text_status": "public", "note": "This work was supported by tbe\nNational Aeronautics and Space Administration\nResearch Grant No. NaG-172-60: GALCIT 120\n\nSubmitted - GALCIT_SM_62-1.pdf
", "abstract": "A continuing study of plane stress singularities at\ncorners and cracks has been extended to the case of a crack in.\na hard (soft) material ending normal to a continuous interface\nwith a soft (hard) material. The increase (decrease) in stress\nsingularity over the homogeneous material case. which is of the\ncharacteristic inverse square root of distance from the crack\npoint, is given for all relative rigidities between zero and\ninfinity. Associated changes in the principal stress and\ndistortion strain energy density distribution are also discussed,\nalong with indications of application to such situations as\nmicrocrack growth near grain boundaries and earth faults in\nlayered strata.", "date": "1962-01", "date_type": "published", "publisher": "California Institute of Technology", "id_number": "CaltechAUTHORS:20140407-142817986", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140407-142817986", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA", "grant_number": "NaG-172-60" } ] }, "other_numbering_system": { "items": [ { "id": "120", "name": "GALCIT Report" } ] }, "local_group": { "items": [ { "id": "Graduate-Aeronautical-Laboratories-(Solid-Mechanics)" }, { "id": "GALCIT" } ] }, "doi": "10.7907/td35-7v74", "primary_object": { "basename": "GALCIT_SM_62-1.pdf", "url": "https://authors.library.caltech.edu/records/0dj70-xne88/files/GALCIT_SM_62-1.pdf" }, "pub_year": "1962", "author_list": "Zak, A. R. and Williams, M. L." }, { "id": "https://authors.library.caltech.edu/records/b636n-43f27", "eprint_id": 51777, "eprint_status": "archive", "datestamp": "2023-08-19 03:55:56", "lastmod": "2025-01-30 03:59:49", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Schapery-R-A", "name": { "family": "Schapery", "given": "R. A." } } ] }, "title": "Two Simple Approximate Methods of Laplace Transform Inversion for Viscoelastic Stress Analysis", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 1961 California Institute of Technology.\n\nPortions of this work were sponsored by the Mechanics Branch,\nAeronautical Research Laboratory\nWright Air Development Division\nContract No. AF 33(616)-8399, GALCIT 119.\n\nSubmitted - SM_61-23.pdf
", "abstract": "Two approximate methods of Laplace transform inversion are given which are simple to use and are particularly applicable to stress analysis problems in quasi-static linear viscoelasticity. Once an associated elastic\nsolution is known numerically or analytically, the time-dependent viscoelastic response can be easily calculated using realistic material properties,\nregardless of how complex the property dependence of the elastic solution may be. The new feature of these methods is that it is necessary to know only 1) an elastic solution numerically for certain ranges of elastic constants and 2) numerical values of the operational moduli or compliances\nfor real, positive values of the transform parameter. One method utilizes a mathematical property of the Laplace transform, while the other is based on some results obtained from Irreversible Thermodynamics and variational\nprinciples. Because of this, they are quite general and can be used with anisotropic and inhomogeneous materials. Two numerical examples are given: As the first one, we calculate the time-dependent strain in a long,\ninternally. pressurized cylinder with an elastic case. The second example consists of inverting a transform which was derived by Muki and Sternberg in the thermo-viscoelastic analysis of a slab and a sphere(1). Both methods\nwere found to provide results which are within the usual engineering requirements of accuracy. Application of the approximate methods to problems in dynamic viscoelasticity is discussed briefly.\n\nSupplementing the stress analysis, two techniques for calculating operational moduli and compliances from experimental stress-strain data are discussed and applied. Both can be used with creep, relaxation, and\nsteady-state oscillation data. The most direct one consists of numerically integrating experimental data, while the other is a model-fitting scheme. With this latter method finite-element spring and dashpot models are readily\nfound which fit the entire response.curves. In using these methods to calculate the operational functions employed in the stress analysis examples, we found that model-fitting was the fastest of the two, yet was very accurate.", "date": "1961-11", "date_type": "published", "publisher": "California Institute of Technology", "id_number": "CaltechAUTHORS:20141114-114344034", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141114-114344034", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "AF 33(616)-8399" } ] }, "other_numbering_system": { "items": [ { "id": "61-23", "name": "GALCIT Report SM" } ] }, "local_group": { "items": [ { "id": "Graduate-Aeronautical-Laboratories-(Solid-Mechanics)" }, { "id": "GALCIT" } ] }, "doi": "10.7907/y7eq-dk48", "primary_object": { "basename": "SM_61-23.pdf", "url": "https://authors.library.caltech.edu/records/b636n-43f27/files/SM_61-23.pdf" }, "pub_year": "1961", "author_list": "Schapery, R. A." }, { "id": "https://authors.library.caltech.edu/records/5dasw-zyj96", "eprint_id": 58009, "eprint_status": "archive", "datestamp": "2023-08-19 03:31:14", "lastmod": "2025-01-30 04:04:22", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Blatz-P-J", "name": { "family": "Blatz", "given": "P. J." } }, { "id": "Knauss-W-G", "name": { "family": "Knauss", "given": "W. G." } }, { "id": "Schapery-R-A", "name": { "family": "Schapery", "given": "R. A." } }, { "id": "Williams-M-L", "name": { "family": "Williams", "given": "M. L." } } ] }, "title": "Fundamental Studies Relating to Systems Analysis of Solid Propellants, January 1, 1960-May 31, 1960", "ispublished": "unpub", "full_text_status": "public", "note": "15 June 1960.\n\nProgress Report No. 6 - GALCIT 101. Subcontract no. R-69752 January 1, 1960 - May 31, 1960. This research is supported by The Thiokol Chemical Corp., Redstone Division.\n\nSubmitted - Progress_Report_No._6__-Galcit_101.pdf
", "abstract": "Previous reports of this series have attempted to\ndefine some of the important parameters affecting structural\nintegrity of solid propellant rocket grains. Three general\nareas have been discussed, namely material properties,\nanalytical procedures, and criteria for mechanical failure.\n\nThis particular report is devoted to failure criteria,\nincluding both limiting deformation and fracture. First of all, the characteristic material properties of filled and unfilled elastomers are described, followed by a brief description of current and proposed tests which can be conducted to obtain experimental information relating to these characteristics in such a form that they can be incorporated in structural integrity analyses. In particular, the necessity for multi-axial\ntests is stressed in conjunction with minor requirements\nfor new experimental equipment.\n\nThe selection of appropriate fracture criteria is discussed.\nMost progress, however, can be reported only in criteria for\nunfilled elastomers for small and large strains where it appears a distortion strain energy density may be used. It is necessary to delay any really definitive remarks upon filled elastomers or actual grain composites, and subsequent use with cumulative\ndamage analyses, until additional experimental data for propellants is forthcoming.", "date": "1960-06-15", "date_type": "published", "publisher": "California Institute of Technology", "id_number": "CaltechAUTHORS:20150604-135847602", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150604-135847602", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Thiokol Chemical Corporation", "grant_number": "R 69752" } ] }, "other_numbering_system": { "items": [ { "id": "101-6", "name": "GALCIT Report SM" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Graduate-Aeronautical-Laboratories-(Solid-Mechanics)" } ] }, "doi": "10.7907/6wsw-zw77", "primary_object": { "basename": "Progress_Report_No._6__-Galcit_101.pdf", "url": "https://authors.library.caltech.edu/records/5dasw-zyj96/files/Progress_Report_No._6__-Galcit_101.pdf" }, "pub_year": "1960", "author_list": "Blatz, P. J.; Knauss, W. G.; et al." }, { "id": "https://authors.library.caltech.edu/records/ge1wj-66q37", "eprint_id": 62591, "eprint_status": "archive", "datestamp": "2023-08-19 03:26:13", "lastmod": "2025-01-30 04:10:50", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Blatz-P-J", "name": { "family": "Blatz", "given": "P. J." } }, { "id": "Knauss-W-G", "name": { "family": "Knauss", "given": "W. G." } }, { "id": "Schapery-R-A", "name": { "family": "Schapery", "given": "R. A." } }, { "id": "Stimpson-L-D", "name": { "family": "Stimpson", "given": "L. D." } }, { "id": "Williams-M-L", "name": { "family": "Williams", "given": "M. L." } } ] }, "title": "Fundamental Studies Relating to Systems Analysis of Solid Propellants, October l, 1959-December 31, 1959", "ispublished": "unpub", "full_text_status": "public", "note": "15 January 1960.\n\nProgress Report No. 5 - GALCIT 101 Subcontract no. RU-293 October 1, 1959 - December 31, 1959. This research is supported by The Thiokol Chemical Corp., Redstone Division.\n\nSubmitted - Fundememtal_Studies_Relating_To_Systems_Analysis_Of_Solid_Propellants_Report_No_101-5.pdf
", "abstract": "Previous reports of this series have attempted to define some of the important parameters affecting the structural integrity of solid propellant rocket grains. Three general areas have been discussed, namely material properties, analytical procedures, and criteria for mechanical\nfailure.\n\nThis particular report is devoted to a more detailed examination of the properties of a filled viscoelastic resin, and their representation by appropriate mechanical models. In addition, a comparison of two methods of computing viscoelastic strains in a pressurized cylinder is\npresented.\n\nIn the category of material properties, linear viscoelastic model theory is reviewed, and certain important relations among sets of experimental data are deduced. A justification for the application of this theory is provided by the analytic representation of available dynamic\ndata in terms of a well-known distribution function. Since the inception of this work additional experimental data on propellants has become available.\n\nIn the category of analytical procedures, the usual approach of representing material properties by a four-element model, as determined from the dynamic data in a limited frequency range, is compared with the\nmore sophisticated Fourier transform method in which the entire frequency range is utilized. The two approaches are applied to calculate the viscoelastic hoop strain at the inner boundary of an internally pressurized infinitely\nlong hollow cylinder subjected to a ramp-type pressure pulse. In this example, the dilatation is assumed elastic or frequency independent and the distortion viscoelastic.\n\nIn the following quarter, primary effort will be devoted to the determination of a criterion for mechanical failure of propellants. Two steps are involved. One is the analytical representation of ultimate strain as a function of temperature on strain rate by means of a mechanical model. In addition to the usual distribution of relaxation (or retardation) times, this model will be supplied with a distribution of ultimate strain. Step two involves\nthe choice of a suitable criterion for compounding ultimate strain or ultimate stress components into a single parameter, which, when exceeded at a given\nrate and temperature, denotes the onset of fracture or mechanical failure.", "date": "1960-01-15", "date_type": "published", "publisher": "California Institute of Technology", "id_number": "CaltechAUTHORS:20151203-165233805", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151203-165233805", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Thiokol Chemical Corporation", "grant_number": "RU-293" } ] }, "other_numbering_system": { "items": [ { "id": "101-5", "name": "GALCIT Report SM" } ] }, "local_group": { "items": [ { "id": "Graduate-Aeronautical-Laboratories-(Solid-Mechanics)" }, { "id": "GALCIT" } ] }, "doi": "10.7907/0sxn-1k84", "primary_object": { "basename": "Fundememtal_Studies_Relating_To_Systems_Analysis_Of_Solid_Propellants_Report_No_101-5.pdf", "url": "https://authors.library.caltech.edu/records/ge1wj-66q37/files/Fundememtal_Studies_Relating_To_Systems_Analysis_Of_Solid_Propellants_Report_No_101-5.pdf" }, "pub_year": "1960", "author_list": "Blatz, P. J.; Knauss, W. G.; et al." }, { "id": "https://authors.library.caltech.edu/records/mwjhp-6ft75", "eprint_id": 62590, "eprint_status": "archive", "datestamp": "2023-08-19 03:16:28", "lastmod": "2025-01-30 04:10:48", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Schapery-R-A", "name": { "family": "Schapery", "given": "R. A." } }, { "id": "Stimpson-L-D", "name": { "family": "Stimpson", "given": "L. D." } }, { "id": "Williams-M-L", "name": { "family": "Williams", "given": "M. L." } } ] }, "title": "Fundamental Studies Relating to Systems Analysis of Solid Propellants, January 1, 1959-March 31, 1959", "ispublished": "unpub", "full_text_status": "public", "note": "Progress Report No. 2 - GALCIT 101 Subcontract No. RU-293 January 1, 1959 - March 31, 1959. This research is supported by The Thiokol Chemical Corp., Redstone Division.\n\nSubmitted - Fundememtal_Studies_Relating_To_Systems_Analysis_Of_Solid_Propellants_Report_No_101-2.pdf
", "abstract": "In continuing the investigation of analysis procedures to be used in studying the structural integrity of solid propellant grains, we amplify the content of the first progress report without at this time opening up any new areas. However it is perhaps appropriate to enumerate some of the specific subjects to be presented later. Following\nthe earlier pattern of (1) model representation and (2) tabulated elastic solutions, both of which are supplemented in this report, it is expected to include (3) heat transfer and temperature distributions, (4) engineering analysis, i.e. the practical combination of items (1), (2),\nand possibly (3) above, (5) failure criteria and strength analysis.", "date": "1959-04-15", "date_type": "published", "publisher": "California Institute of Technology", "id_number": "CaltechAUTHORS:20151203-164854569", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151203-164854569", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Thiokol Chemical Corporation" } ] }, "other_numbering_system": { "items": [ { "id": "101-2", "name": "GALCIT Report SM" } ] }, "local_group": { "items": [ { "id": "Graduate-Aeronautical-Laboratories-(Solid-Mechanics)" }, { "id": "GALCIT" } ] }, "doi": "10.7907/822k-jv84", "primary_object": { "basename": "Fundememtal_Studies_Relating_To_Systems_Analysis_Of_Solid_Propellants_Report_No_101-2.pdf", "url": "https://authors.library.caltech.edu/records/mwjhp-6ft75/files/Fundememtal_Studies_Relating_To_Systems_Analysis_Of_Solid_Propellants_Report_No_101-2.pdf" }, "pub_year": "1959", "author_list": "Schapery, R. A.; Stimpson, L. D.; et al." }, { "id": "https://authors.library.caltech.edu/records/r0xbp-gn259", "eprint_id": 62589, "eprint_status": "archive", "datestamp": "2023-08-19 03:13:46", "lastmod": "2025-01-30 04:10:46", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Schapery-R-A", "name": { "family": "Schapery", "given": "R. A." } }, { "id": "Stimpson-L-D", "name": { "family": "Stimpson", "given": "L. D." } } ] }, "title": "Fundamental Studies Relating to Systems Analysis of Solid Propellants, October 1, 1958- December 31, 1958", "ispublished": "unpub", "full_text_status": "public", "note": "Progress Report No. 1 - GALCIT 101 Subcontract No. RU-293 October 1, 1958 - December 31, 1958. This research is supported by The Thiokol Chemical Corp., Redstone Division.\n\nSubmitted - Fundamental_Studies_Releting_To_Systems_Analysis_of_Solid_Propellants__Rep_No.101-1.pdf
", "abstract": "In this report the groundwork is laid for the proposed work scope which stressed the need for a greater understanding of the solid mechanics of grains. Particular emphasis will be directed toward the multi-axial behavior of thick walled configurations. The work falls naturally into\nthree areas; (1) analysis procedures, (2) material properties, and (3) failure criteria.\n\nAs a necessary preliminary to treating specific designs, certain material of general applicability must be developed, collected, and summarized. The following sections therefore deal with a general\ndescription of viscoelastic analysis and material representation, discussed by contrast with more conventional engineering analysis. By this means\na background is established for the collection of elastic design formulas which are included in the second section of the report.", "date": "1959-01-15", "date_type": "published", "publisher": "California Institute of Technology", "id_number": "CaltechAUTHORS:20151203-155555299", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151203-155555299", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Thiokol Chemical Corporation" } ] }, "other_numbering_system": { "items": [ { "id": "101-1", "name": "GALCIT Report SM" } ] }, "local_group": { "items": [ { "id": "Graduate-Aeronautical-Laboratories-(Solid-Mechanics)" }, { "id": "GALCIT" } ] }, "doi": "10.7907/rnjk-nb74", "primary_object": { "basename": "Fundamental_Studies_Releting_To_Systems_Analysis_of_Solid_Propellants__Rep_No.101-1.pdf", "url": "https://authors.library.caltech.edu/records/r0xbp-gn259/files/Fundamental_Studies_Releting_To_Systems_Analysis_of_Solid_Propellants__Rep_No.101-1.pdf" }, "pub_year": "1959", "author_list": "Schapery, R. A. and Stimpson, L. D." }, { "id": "https://authors.library.caltech.edu/records/swpdr-9a225", "eprint_id": 62673, "eprint_status": "archive", "datestamp": "2023-08-19 03:12:12", "lastmod": "2025-01-30 04:11:14", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Williams-M-L", "name": { "family": "Williams", "given": "M. L." } } ] }, "title": "The Importance of Structural Integrity in Grain Design", "ispublished": "unpub", "full_text_status": "public", "note": "Extracted from the Proc. 15th Meeting of the Joint Army-Navy-Air Force Solid Propellant Group, Washington D.C., June 1959.\n\nSubmitted - The_Importance_of_Structural_Integrity_in_Grain_Design.pdf
", "abstract": "During the past several years solid propellant power units have changed in many ways. Notwithstanding the increase in specific impulse, probably the most striking of all is the remarkable growth in its physical size. This past and probably future growth has been accompanied by a proportionate rise in the cost of propellant units. The point of reviewing these facts is to stress an obvious but important fact. Grains are not cheap. The corollary is that it behooves the rocket engineer to bend every effort to design a grain which will not abort. He should carefully consider the use of scale models, laboratory testing, and analytical procedures.\n\nTurning specifically to the problem of structural design, we find that there is a fundamental yet simple distinction between the liquid and solid propellant fuel. the liquid fuel supports only hydrostatic compression; the solid fuel, on the other hand, not only withstands the same loading, but also varying amounts of tension and shear stress. From the mechanical standpoint this is a mixed blessing. If the grain material will take load, it is inefficient not to use this capability. But the material will also tend to absorb load, irrespective of the designers wishes. As a minimum requirement, therefore, a grain must be designed such that its proclivity to absorb load does not contribute to a rocket failure. Then, if possible, design it in such a way that its ability to absorb load contributes to a higher loading fraction, lower system weight, or improved overall performance. To reiterate, the structural integrity of a solid grain has a much stronger interaction with the overall system design than the liquid fuel, because a structural failure in the solid grain can contribute to off-design burning or even catastrophic ignition.\n\nWith these introductory remarks, it is desired to emphasize the economic and technical feasibility of conducting more sophisticated structural analyses of the grain than has heretofore been customary.", "date": "1959", "date_type": "published", "publisher": "California Institute of Technology", "id_number": "CaltechAUTHORS:20151207-171652867", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151207-171652867", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Graduate-Aeronautical-Laboratories-(Solid-Mechanics)" }, { "id": "GALCIT" } ] }, "doi": "10.7907/gta6-t193", "primary_object": { "basename": "The_Importance_of_Structural_Integrity_in_Grain_Design.pdf", "url": "https://authors.library.caltech.edu/records/swpdr-9a225/files/The_Importance_of_Structural_Integrity_in_Grain_Design.pdf" }, "pub_year": "1959", "author_list": "Williams, M. L." }, { "id": "https://authors.library.caltech.edu/records/xhynf-0nf57", "eprint_id": 62669, "eprint_status": "archive", "datestamp": "2023-08-19 03:09:57", "lastmod": "2025-01-30 04:11:07", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Williams-M-L", "name": { "family": "Williams", "given": "M. L." } }, { "id": "Jessey-M-E", "name": { "family": "Jessey", "given": "M. E." } }, { "id": "Parmerter-R-R", "name": { "family": "Parmerter", "given": "R. R." } } ] }, "title": "Some Exploratory Photoelastic Studies in Stress Wave Propagation", "ispublished": "unpub", "full_text_status": "public", "note": "This research was supported by the United States Bureau of Ordnance, through the Naval Ordnance Test Station, China Lake, California, Dr. John Pearson, Project Engineer.\n\nN123-60530S-3825a: T.O. 1.\n\nSubmitted - Some_Exploratory_Photoelastic_Studies_in_Stress_Wave_Propagation.pdf
", "abstract": "During the last three years the Guggenheim\nAeronautical Laboratory of the California Institute of\nTechnology (GALCIT) has been conducting a photoelastic\nstudy of stress wave propagation in solids\nusing a high speed framing camera.\n\nThis paper presents a technical description of\nthe camera, now operating at 100,000 35 mm frames\nper second at one tenth microsecond exposure time\nfor an elapsed time of approximately two milliseconds.\nThe design capability is expected to approach a half\nmillion frames per second. This equipment has been\nused to record dynamic photoelastic stress fringe\npatterns in various specimens under impact loadings.\nTypical experimental records of wave propagation in\ncracked plates, layered media, compressed bars and\nbeams, and cross sections of rocket heads are included\nin this report.", "date": "1958-10", "date_type": "published", "publisher": "California Institute of Technology", "id_number": "CaltechAUTHORS:20151207-164957856", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151207-164957856", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "U.S. Navy Bureau of Ordnance" } ] }, "other_numbering_system": { "items": [ { "id": "90", "name": "GALCIT Report SM" } ] }, "local_group": { "items": [ { "id": "Graduate-Aeronautical-Laboratories-(Solid-Mechanics)" }, { "id": "GALCIT" } ] }, "doi": "10.7907/12v0-1266", "primary_object": { "basename": "Some_Exploratory_Photoelastic_Studies_in_Stress_Wave_Propagation.pdf", "url": "https://authors.library.caltech.edu/records/xhynf-0nf57/files/Some_Exploratory_Photoelastic_Studies_in_Stress_Wave_Propagation.pdf" }, "pub_year": "1958", "author_list": "Williams, M. L.; Jessey, M. E.; et al." }, { "id": "https://authors.library.caltech.edu/records/a92qn-rqp24", "eprint_id": 62674, "eprint_status": "archive", "datestamp": "2023-08-19 01:18:45", "lastmod": "2025-01-30 04:11:16", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Fung-Yuan-Cheng", "name": { "family": "Fung", "given": "Y. C." } } ] }, "title": "The Problem of the Cantilever Plate", "ispublished": "unpub", "full_text_status": "public", "note": "Submitted - The_problem_of_the_cantilever_plate.pdf
", "abstract": "[no abstract]", "date": "1947-10-21", "date_type": "published", "publisher": "California Institute of Technology", "id_number": "CaltechAUTHORS:20151207-172735760", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151207-172735760", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Graduate-Aeronautical-Laboratories-(Solid-Mechanics)" }, { "id": "GALCIT" } ] }, "doi": "10.7907/ne79-d457", "primary_object": { "basename": "The_problem_of_the_cantilever_plate.pdf", "url": "https://authors.library.caltech.edu/records/a92qn-rqp24/files/The_problem_of_the_cantilever_plate.pdf" }, "pub_year": "1947", "author_list": "Fung, Y. C." } ]