Uniform crashworthiness optimization of car body for high-speed trains

Abstract

The paper deals with a new uniform crashworthiness concept of car bodies optimization of high-speed trains. The design optimization was done from the point of view of structural protection of occupants' survival space. For the reason that it is impossible to find a highly probable scenario for the derailment, the authors decided to find the solution in the form of rigid frame structure (survival cells), which will provide safety space for the passengers.In the optimization example a typical passenger car body was divided into cells of approximately equal dimensions. The optimization problem was to minimize the mass of the structure with stress constraints. The survival cell was subjected to a sequence of high value loads. The loads are acting in an asynchronous way in three load directions what gives the optimized structure uniform crashworthiness.The optimization strategy consists of three stages. In the first step, the constant criterion surface algorithm (CCSA) of topology optimization is applied to find a preliminary solutions. For improving the manufacture properties of this solution, a new concept of design space constraints was proposed. The sizing optimization with evolutionary algorithms was used to define a thin-walled structure in the second step. For evolutionary optimization a standard procedure was employed. Finally, CCSA optimization algorithm was This paper was presented in the 9th World Congress on Structural and Multidisciplinary Optimization, International Society for Structural and Multidisciplinary Optimization, Shizuoka, Japan, 2011 M. Mrzygłód · T. Kuczek ( ) Institute of Rail Vehicles, Cracow University of Technology, al. Jana Pawła II 37, Kraków, M. Mrzygłód e-mail: mrzyglod@mech.pk.edu.pl applied again to remove excessive material from a car body structure. As the optimization result a new design proposition of a car body with multiple survival cells of high uniform stiffness was obtained. By maintaining passengers' survival space, the passive safety of a high-speed car body was significantly increased.

Application of manufacturing constraints to structural optimization of thin-walled structures

“…The stiffness of this model was tuned to reach the value of linear deformation equal to the first model (Mrzyglod and Kuczek, 2014). After the Young's modulus was reduced to a value of E 2 = 2.3E + 010 N/m 2 the maximum linear deformation of the cube increased to a value of d 2 = 2.42E − 005 mm.…”

Substantiating the optimization of the load-bearing structure of a hopper car for transporting pellets and hot agglomerate

“…Paper [8] considers the unified concept of impact strength in order to optimize a rolling stock body. The car body was represented in the form of a rigid frame structure.…”

“…In this case, equations (4) and (5) characterize the displacement of a car body at oscillations due to jumps and galloping. Equations (6) and 7refer to the undercarriage traveling first in the forward direction, (8) and 9-second.…”

Optimization Analysis of Energy-Absorbing Structures in Subway Train

“…Mrzygłód and Kuczek proposed a new crashworthiness concept in the optimization problem of car bodies for high-speed trains to provide more safety redundancies for the passengers, which also realized the lightweight of the structure under stress constraints [11]. Kim et al applied topology optimization for shell frame of leading-car structure to enhance crash energy absorption in the conceptual design phase [12].…”