The Influence of Stiffness Decay on Fatigue Reliability of Truss System

摘要

Physical properties of element are very complex under fatigue loads.The structural system consisted of elements is not a simple topological structure,which the change of its physical properties is more complex.In order to analyze quantitatively the structural stiffness reliability of different design life,it is important to establish the accurate formula of physical properties decrease. In this paper, the formula of elements' elastic modulus decrease is deduced by using damage mechanics theory combining with the model of residual strength of element. Moreover, stiffness reliability index of controlling node of truss system is solved by applying the Stochastic Finite Element Method in different service life.