Time-variant redundancy of structural systems

Abstract

Structural redundancy is expected to change over time due to time-variant loading and damage under uncertainties. The objective of this paper is to investigate the time-variant redundancy of structural systems. Analyses of structural reliability and redundancy affected by deterioration in structural resistance and increase in applied loads are conducted by using numerical examples. It is shown that the structural system redundancy is influenced by several factors, such as the material type, the resistance correlation structure and deterioration rate and the rate of increase in applied loads. The results show the importance of including the time factor in the quantification of redundancy. Such results are useful for identifying the best measures to take in order to maintain a satisfactory level of redundancy throughout the life of structural systems and to incorporate the time-variant redundancy in a lifetime-oriented multi-objective optimisation framework of risk-based management of structural systems.