[ { "id": "https://authors.library.caltech.edu/records/hfsy1-xhq05", "eprint_id": 62363, "eprint_status": "archive", "datestamp": "2023-08-19 03:35:44", "lastmod": "2023-10-25 17:05:32", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Rosakis-A-J", "name": { "family": "Rosakis", "given": "A. J." }, "orcid": "0000-0003-0559-0794" }, { "id": "Samudrala-O", "name": { "family": "Samudrala", "given": "O." } }, { "id": "Coker-Demirkan", "name": { "family": "Coker", "given": "D." }, "orcid": "0000-0001-7385-7089" } ] }, "title": "Cracks Faster Than the Shear Wave Speed", "ispublished": "unpub", "full_text_status": "public", "note": "The authors would like to acknowledge the support of the National Science Foundation (Grant # CMS9424113) and the Office of Naval Research (Grant # N00014-95-0453).\n\n
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": "2015-11-24", "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" }, "resource_type": "monograph", "pub_year": "2015", "author_list": "Rosakis, A. J.; Samudrala, O.; et el." }, { "id": "https://authors.library.caltech.edu/records/rz0hf-4v226", "eprint_id": 55628, "eprint_status": "archive", "datestamp": "2023-08-20 00:48:10", "lastmod": "2023-10-20 22:26:48", "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" }, "resource_type": "monograph", "pub_year": "1992", "author_list": "Rosakis, A. J.; Mason, J. J.; et el." } ]