Experimental and numerical studies on composite tubes for the energy absorber of Korean TTX

Abstract

Korea is building a light weight tilting train (Korean TTX) using composite material, which can tilt itself to a maximum angle of $8^0$ at the corner to maintain high speed during operating time. For any train or vehicle, the crashworthiness is very important. This research studies the ability of the composite material to be used for the Energy Absorber of the Korean TTX as a combination of several composite tubes. Experimental and numerical studies were done dealing with the quasi static test of the composite tube. The purpose of experimental study is to find out which lay-up is the best lay-up for the Energy Absorber. The best lay-up is the one that has the highest Energy Absorption (EA) and Specific Energy Absorption ($E_S$). Four lay-ups were tested using quasi static method: $[0/45/90/-45]_4$, $[0]_{16}, [0/90]_8$, $[0/30/-30]_5$. Two triggering methods were used to create initial damage and guarantee the progressive collapse mode: bevel edge and slope edge. As a result, $[0/45/90/-45]_4$ lay-up was find out the best lay-up among the laminates being tested. A parametric analysis was done to find out the most proper way to simulate the quasi static test of composite tube using LS DYNA program. A single composite tube was modeled to be crashed by a moving wall. Comparison between simulation and experiment was done. Dealing with parameter TFAIL and the mass scaling factor, this parametric study shows the ability and the limitation of LS DYNA in modeling the quasi static test for the composite tube.