Strain Rate Effects During Ultra-High Strain Rate Penetration of Polymeric Materials

ORAL

Abstract

Energy dissipation during penetration of a material is an important consideration in designing lightweight armor to protect structures, equipment, and personnel from impact damage. A series of impact tests, with projectile velocities in the range 2-7 km/s, was performed on monolithic plates of ultra-high molecular weight polyethylene (UHMWPE), high density polyethylene (HDPE), and poly(methyl methacrylate) (PMMA). A relationship between back face debris cloud (BFDC) velocity and impact velocity was developed for each material. Damage zone sizes were compared, offering insights into the effects of molecular architecture on stress delocalization and energy dissipation during perforation. Monolithic plate thicknesses were varied in the UHMWPE and HDPE target populations to assess thickness effects on damage zone size and BFDC. Comparison of the apparent failure mechanisms and damage metrics, in conjunction with thermal analysis, were used to explain the relative performance of each material. PMMA demonstrated glass-like failure with finely particulated BFDCs, while perforation of HDPE resulted in fluid-like BFDCs. UHMWPE damage morphology possessed qualities of both PMMA and HDPE.

Permission to publish was granted by Director, Geotechnical & Structures Laboratory

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Presenters

  • Santanu Kundu

    Mississippi State University, Dave C Swalm School of Chemical Engineering, Mississippi State University, Chemical Engineering, Mississippi State University

Authors

  • M. Hunter Bowering

    Dave C Swalm School of Chemical Engineering, Mississippi State University

  • W. F. Heard

    U. S. Army ERDC

  • Thomas E. Lacy, Jr

    Mechanical engineering, Texas A&M University, Department of Mechanical Engineering, Teaxs A&M University

  • Charles U. Pittman, Jr.

    Department of Chemistry, Mississippi State University

  • Santanu Kundu

    Mississippi State University, Dave C Swalm School of Chemical Engineering, Mississippi State University, Chemical Engineering, Mississippi State University