[
    {
        "id": "authors:4mcdv-8th68",
        "collection": "authors",
        "collection_id": "4mcdv-8th68",
        "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190918-090257435",
        "type": "book_section",
        "title": "A Technique to Predict Clefting of Lobed Super-Pressure Balloons",
        "book_title": "11th AIAA Aviation Technology, Integration, and Operations (ATIO) Conference",
        "author": [
            {
                "family_name": "Pellegrino",
                "given_name": "S.",
                "orcid": "0000-0001-9373-3278",
                "clpid": "Pellegrino-S"
            },
            {
                "family_name": "Deng",
                "given_name": "X.",
                "clpid": "Deng-Xiaowei"
            }
        ],
        "abstract": "Lobed super-pressure balloons have shown a tendency to deploy into unexpected asymmetric shapes, hence their design has to strike a balance between the lowest stresses achieved by increasing lobing and the risk of incomplete deployment. This paper proposes a computational clefting test that can be applied to any given balloon design. The test consists in setting up the balloon in its symmetrically inflated configuration, then breaking the symmetry of this shape by artificially introducing a clefting imperfection, and finally determining the equilibrium shape of the balloon. Wrinkling of the balloon film and frictionless contact are included in the computation. The clefting test is applied successfully to three 27 m diameter super-pressure balloons that have been tested indoors by NASA, of which one had remained clefted when it was inflated and the other two had deployed completely.",
        "doi": "10.2514/6.2011-6830",
        "isbn": "978-1-60086-941-9",
        "publisher": "American Institute of Aeronautics and Astronautics",
        "place_of_publication": "Reston, VA",
        "publication_date": "2012-06-04",
        "pages": "Art. No. 2011-6830"
    },
    {
        "id": "authors:j5q84-a3730",
        "collection": "authors",
        "collection_id": "j5q84-a3730",
        "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200330-082659500",
        "type": "book_section",
        "title": "Computation of Partially Inflated Shapes of Stratospheric Balloon Structures",
        "book_title": "49th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, 16th AIAA/ASME/AHS Adaptive Structures Conference, 10th AIAA Non-Deterministic Approaches Conference, 9th AIAA Gossamer Spacecraft Forum",
        "author": [
            {
                "family_name": "Deng",
                "given_name": "X.",
                "clpid": "Deng-Xiaowei"
            },
            {
                "family_name": "Pellegrino",
                "given_name": "S.",
                "orcid": "0000-0001-9373-3278",
                "clpid": "Pellegrino-S"
            }
        ],
        "abstract": "This paper studies the relationship between height, volume and stress distribution in a superpressure pumpkin balloon with the differential pressure applied to the balloon. Two different approaches are presented. A simple two-dimensional solution based on previous work and a novel, detailed finite element simulation that provides three-dimensional solutions are investigated. It is found that the finite element solution provides a much better agreement with experimental results for the case of a flat facet ULDB balloon. It is also found that a region of tensile hoop stress remains in the crown region of the balloon until the bottom pressure becomes negative. This region prevents the formation of clefts in the balloon and keeps its shape axisymmetric.",
        "doi": "10.2514/6.2008-2133",
        "isbn": "978-1-60086-993-8",
        "publisher": "American Institute of Aeronautics and Astronautics",
        "place_of_publication": "Reston, VA",
        "publication_date": "2008-04-07",
        "pages": "Art. No. 2008-2133"
    }
]