A General Purpose Software For Reliability-Based Optimal Design

Abstract

Due to the inherent uncertainties in loads, materials and manufacturing quality, variabilities are unavoidable in structural responses and can cause significant deviations in expected product performance. To ensure the reliability of a structure, these uncertainties must be considered during structural design. In cases where a structure is optimized such that the design requirements are barely met, it is important for engineers to asses the design's reliability and, if necessary, optimize the structure considering the reliability requirement. In those situations where variations in design and operating environment result in considerable variability of the performance of a system, it is critical for engineers to search for a robust design. A robust design is one in which the performance deviation is within acceptable limits. The objective of this paper is to present a life cycle management tool implemented within a general purpose stochastic analysis software named COSSAN-XTM . An overview of the tools for reliability and optimization implemented in the code which are required to solve the robust design problem is presented. In addition, the interaction with deterministic Finite Element codes is also addressed. The salient features of the software are presented by means of a challenging problem of Reliability based optimization and life cycle management.