Title: Multi-objective optimisation of hybrid S-shaped rails under oblique impact loading

Authors: Linli Tian; Yunkai Gao; Jianguang Fang; Xiuzhe An

Addresses: School of Automotive Studies, Tongji University, No. 4800 Cao'an Road, Shanghai, China ' School of Automotive Studies, Tongji University, No. 4800 Cao'an Road, Shanghai, China ' School of Automotive Studies, Tongji University, No. 4800 Cao'an Road, Shanghai, China ' School of Automotive Studies, Tongji University, No. 4800 Cao'an Road, Shanghai, China

Abstract: This paper aims at optimising the crashworthiness capabilities of hybrid S-shaped rails of an automotive body under oblique impact loading. In the optimisation process, geometrical parameters, material types and the length ratios of aluminium part to the whole length are taken as design variables. Kriging metamodel techniques are performed to predict the crashworthiness criteria of specific energy absorption (SEA) and peak crushing force (PCF). In the following multi-objective optimisation design (MOD), non-dominated sorting genetic algorithm (NSGA-II) is adopted to obtain maximum SEA capacity and minimum PCF of hybrid S-shaped rails. It is found that the optimum design for a specific load angle does not necessarily guarantee the best solution when the load angle changes. More importantly, the change of weighting factor for each load angle affects the Pareto front of such MOD considerably, and thus selecting proper weights is of great importance in the crashworthiness design of hybrid S-shaped rails.

Keywords: oblique impact loading; multi-objective optimisation; crashworthiness; hybrid materials; load angle uncertainty; hybrid S-shaped rails; automotive body; car body; steel; aluminium; longitudinal side members; energy absorption; metalmodelling; design of experiments; DoE; structural optimisation; NSGA-II; genetic algorithms.

DOI: 10.1504/IJHVS.2015.070450

International Journal of Heavy Vehicle Systems, 2015 Vol.22 No.2, pp.137 - 156

Received: 31 Dec 2013
Accepted: 13 Jan 2015

Published online: 06 Jul 2015 *

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