Analytical studies on the crashworthiness of steel derailment stopper

Recently, the risk of derailment accident caused by great earthquake is pointed out in Japan. If bullet trains derail and collide against structures at high-speed, unimaginable catastrophic accident would occur. From these circumstances, the steel derailment stopper is proposed as one of the effective measures. However, collision between a rotating wheel and steel derailment stopper become extremely complex phenomenon. Therefore, there is no design concept for the preventive device against derailment accident. This study aims at evaluating crashworthiness of the steel derailment stopper using 3-D elasto-plastic FE analysis. In FE analysis, both target train and steel derailment stopper are modeled assumed as elasto-plastic body and to evaluate precise impact responses of collision wheel and derailment stopper, dynamic contact condition is employed. As each parts of derailment stopper is connected by steel bolt and overall structure is installed on the concrete roadbed, fundamental load capability of steel stopper is investigated by impact analysis that considered fracture possibility of steel bolt and concrete roadbed. After that, influences of impact velocity and incident angle on the crashworthiness of steel derailment stopper are examined by numerical analyses. It is found that critical damage such as cone fracture of concrete roadbed could not be occurred. Furthermore, according to vehicular crash simulations, it is confirmed that steel derailment stopper could withstand a crash of train and alter their trajectory appropriately.