Title: Structural optimisation with reliability-based durability constraints

Authors: Sung-Ling Twu, Maolin Tsai, Ramaswamy Subramanian, Robert V. Lust, M.E.M. El-Sayed

Addresses: North American Operations, General Motors Corporation, Warren, Michigan, 48090 USA. North American Operations, General Motors Corporation, Warren, Michigan, 48090 USA. North American Operations, General Motors Corporation, Warren, Michigan, 48090 USA. North American Operations, General Motors Corporation, Warren, Michigan, 48090 USA. Kettering University, Flint, Michigan 48504, USA

Abstract: This paper describes a reliability-based design optimisation methodology for structural durability that directly considers expected variations in service loads, material characteristics and finite element analysis modelling. The methodology is based on the development of a stochastic durability limit state model. For a given field reliability target, this model can be easily evaluated for known (or assumed) variations; yielding an equivalent deterministic limiting stress. This limiting stress is then used as input (in the form of a durability stress constraint) to an existing structural design optimisation tool which, in turn, is used to generate a mass efficient structural design. Because the variations considered are completely comprehended by the stress constraint, the reliability analysis and the structural optimisation procedure are uncoupled. Therefore, the methodology is computationally efficient. As a demonstration, the new methodology is used to design a typical automobile shock tower interface structure.

Keywords: durability; probabilistic analysis; structural optimization; reliability; reliability-based design; structural design; uncertainty; variation.

DOI: 10.1504/IJVD.2001.001911

International Journal of Vehicle Design, 2001 Vol.25 No.1/2, pp.115-125

Published online: 18 Aug 2003 *

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