Basic approaches to ensuring structural integrity of technical systems

Abstract

Structural reliability of technical systems is to be insured in the presence of high level of uncertainty related to natural variability of loads acting on the system, scatter of mechanical properties of structural materials, inaccuracies of geometrical dimensions, imperfections of test equipment and design models. In the view of these uncertainties two basic approaches to securing structural integrity can be distinguished: deterministic (standard-based) approach founded on the application of the so called safety factors that are introduced into the design equation to compensate uncertainties; and probabilistic (reliability-based) approach that requires that the probability of structural failure occurrence not to exceed some allowable limiting value considered acceptable by society at the current stage of the technological development, available resources and the willingness of the society to pay for the implementation of protection measures. The paper presents a comparative assessment of deterministic and probabilistic approaches to securing structural integrity of technical systems subjected to various types of loading regimes. The condition of the equivalence of these two basic approaches to securing structural integrity is considered.