Temperature Dependent Flexural Rigidities and Thickness Investigation

Abstract

This paper discusses the characterization of temperature-dependent flexural rigidities of Dyneema® HB80, a cross-ply thermoplastic lamina. The properties are then used in the modeling a thermoforming process. A vertical-cantilever experimental setup is presented to characterize the bending behavior at elevatedtemperature conditions. The material properties derived from the test data are implemented in a finite element model of the cross-ply lamina. Thickening of the lamina resulting from shear deformation is investigated and incorporated in the model. The finite element model uses a hybrid discrete mesoscopic approach, and deep draw forming of the material is simulated to investigate its formability to a hemispherical geometry. Simulation results are compared with an experimental forming trial to demonstrate the capabilities of the model to predict the development of out-of-plane waves during preform manufacturing and to inform the design of multiple-ply thermoforming with thickness variation data.