Material characterization of a composite–foam sandwich for the front structure of a high speed train

The material characterization described in the paper is aimed at the structural design of the front shield for a high speed train made of composite material. A sandwich structure was considered, made of glass fiber epoxy face sheets with a polymeric foam core. Initially, the material properties and the rate sensitivity of the skin and core materials were investigated through a series of static and quasi-static tests. Static and dynamic impact tests were then run on the sandwich structure. For all materials tested, no significant strain-rate effects were observed over the range of test conditions investigated in the study. Results show that the structural response of the sandwich depends primarily on the strength properties of the foam core material. The dynamic impact resistance of the sandwich structure was then substantially improved by adding a net of resin walls within the foam.