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A Constitutive Model for Crushable Polymer Foams Used in Sandwich Panels: Theory and FEA Application

Tong, Xiaolong
http://rave.ohiolink.edu/etdc/view?acc_num=akron1596806015399848

Abstract Details

2020, Doctor of Philosophy, University of Akron, Mechanical Engineering.
The objective of this research was to develop a constitutive model for Divinycell PVC H100 foam in order to accurately predict its mechanical behaviors under triaxial crushing. Nowadays, sandwich panels with polymer foam core are widely used because of its low weight-stiffness ratio and high energy absorption capability. Many of these applications require the sandwich panels to have curvature to some extent which causes triaxial stress state in the foam. In this research, a 3D anisotropic elastic-plastic-viscoelastic-damage model was developed to predict the multiaxial crushing behavior of polymer foams used in the core of sandwich structures. This model was based on previous pressure vessel experiments on Divinycell H100, whereby the post-yield response of the foam was characterized by anisotropic hardening during plastic flow, as well as damage and viscoelastic hysteresis. By assuming Tsai-Wu plasticity, post-yield properties from only uniaxial compression/tension and simple shear material responses were used to develop a three-dimensional material constitutive relationship for the foam. This solution methodology was shown to be very effective in predicting the hysteresis response of the foam under triaxial compression, triaxial compression-tension and triaxial compression-shear. Good agreement was found between the theoretical predictions and experimental results. An ABAQUS user-defined subroutine (VUMAT) for the proposed elastic-plastic-viscoelastic-damage model was implemented. By using the VUMAT to simulate the single element and meshed specimen, the proposed material model was verified to be valid and accurate. The VUMAT was then used to simulate the response of a curved sandwich panel with Divinycell H100 foam core under blast load. The results were used to compare with ABAQUS built-in isotropic crushable foam model. Results showed that the commonly-used isotropic crushable foam model overestimated the stiffness, strength and energy dissipation of the sandwich structure with Divinycell H100 foam core. This makes the engineering design using the isotropic crushable foam model inaccurate in satisfying the mechanical requirements and may induce serious safety issues. The proposed elastic-plastic-viscoelastic-damage model provides more accurate results and offers better protection.
Michelle Hoo Fatt (Advisor)
Xiaosheng Gao (Committee Member)
Alper Buldum (Committee Member)
Wieslaw Binienda (Committee Member)
Lingxing Yao (Committee Member)
156 p.
Materials Science; Mechanical Engineering; Mechanics
Elastic; Plastic; Viscoelastic; Damage; Constitutive Model; FEA; VUMAT; Polymer foam; Crushable foam; Divinycell H100; Sandwich structure; Foam core; Blast load; Anisotropic; Tsai-Wu; Computational; Return mapping algorithm; Newton Raphson Iteration;

Recommended Citations

Citations

  • Tong, X. (2020). A Constitutive Model for Crushable Polymer Foams Used in Sandwich Panels: Theory and FEA Application [Doctoral dissertation, University of Akron]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=akron1596806015399848

    APA Style (7th edition)

  • Tong, Xiaolong. A Constitutive Model for Crushable Polymer Foams Used in Sandwich Panels: Theory and FEA Application. 2020. University of Akron, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=akron1596806015399848.

    MLA Style (8th edition)

  • Tong, Xiaolong. "A Constitutive Model for Crushable Polymer Foams Used in Sandwich Panels: Theory and FEA Application." Doctoral dissertation, University of Akron, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=akron1596806015399848

    Chicago Manual of Style (17th edition)

akron1596806015399848
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This open access ETD is published by University of Akron and OhioLINK.