Modelling of strain rate dependent deformation behaviour of polypropylene

Composites with thermoplastic matrices are excellent candidates for the use in impact and crash components of innovative lightweight structures for the aircraft and vehicle industry as well as for mechanical engineering applications. For a reliable structural design of security-relevant, highly dynamically loaded lightweight structures, knowledge of the strain rate dependent material behaviour of the single components of a fibre reinforced composite and the possibility of predicting the stress-strain relations at various strain rates are obligatory. For this purpose, an analytical method based on a Burgers model was developed, which allows the prediction of strain rate dependent behaviour of thermoplastic polymers under tensile loading. For validation of the method, comprehensive material tests on polypropylene were performed with a servo-hydraulic high speed testing unit in combination with specially adapted clamping devices. (C) 2010 Elsevier Ltd. All rights reserved.