Abstract
Despite a recent need for the improvement of train crashworthiness, few design methods have been proposed. To establish it, we tried to introduce the concept of "Crushable Body Structure in automobiles" to the design of train bodies in the past reports. There a train car with crushable zone was modeled by lumped nonlinear springs and masses system. Here characteristic curve of draft gear as to approximate is adopted to real train more exactly, and optimized. In the optimum design, sum of weighted deceleration of the trains was taken as an objective function to be minimized. Then we used 3-cars train model and crush speeds were set to be 15km/h, 25km/h, 35km/h. Optimum characteristics characteristic curve of draft gear is shown. The robustness for velocity is also shown. We introduce and discuss relation of between absorbed energy and decelerations.
