Investigation of Shear Characterization of a UHMWPE Unidirectional Cross-ply for Finite Element Simulation of Composite Processing

摘要

In-plane shearing is the dominant mode of deformation in many composite forming processes, including thermoforming. The shear-frame, or picture-frame, test is a widely accepted method to characterize the shear behavior of a material system to find the properties to use in forming simulations, and this test has been shown to be applicable for providing shear stiffness as a function of the state of shear for a variety of woven-fabrics based material systems. The current research explores the use of shear-frame testing of a non-woven material system made of Ultra High Molecular Weight Polyethylene (UHMWPE), specifically DSM Dyneema? HB210 unidirectional fiber cross-ply. The material system was characterized at an elevated temperature for processing applications. The effects of sample size and sample geometry were investigated. The load contribution from the sample arms is of particular interest for these types of materials, so an investigation of appropriate gage area and normalization methods is performed. Finite element simulations of the shear-frame test are completed to validate the characterization methodology.