Modelling of Polypropylene Subjected to Impact Loading at Low Temperatures

The use of thermoplastics in structural applications requires that engineers can reliably predict their mechanical behaviour. Depending on the intended use, a component must withstand various load cases and environmental factors. This paper seeks to investigate the capabilities of a phenomenological material model to represent polypropylene (PP) plates subjected to a dropped weight impact at low temperatures. The dropped weight tests were performed with an Instron CEAST 9350 Drop Tower Impact System, shown in Figure 1. An incorporated environmental chamber injected with liquid nitrogen enabled sub-room temperature conditions. A total of 11 drop tests were made at five different impact velocities. The material was found to experience moderate plastic deformations until failure through plugging. By comparison of force displacement curves, the tests are found to show good repeatability. Some variations are found with respect to initiation of failure, possibly caused by small variations between the plates or misalignments during tests.