Reliability Analysis And Optimization Design Of Aircraft Structure

The work environment of aircraft is complicated and many indeterminate factors affect structural safe. For example, there are many indeterminate, material date and dimension date provided may be not completely consistent with that of real structure. Some hypothesis, for convenience and simplification, make the calculation model is not the same as the real structure. But aircraft structure is valuable in general; the structural failure will bring on enormous economy losing and endanger life safe of airman and fare. Therefore, it is necessary to make stochastic analysis of aircraft structural systems and to evaluate its reliability. At present, in many cases, reliability analysis of structural systems of strength failure, stiffness failure and fatigue failure is respectively considered. However, it is very possible to have many failure modes of aircraft engineering structures. At first, small fatigue load have caused an amount of damage and decrease the ultimate bearing capability to the structures, then ultimate load have caused wholly destroy. In the other hand, these failure modes have relativity for some parameter. Therefore, reliability analyses of structural systems must simultaneous considers these failure modes in order to respond real case. This thesis has made some progress in this field. Main content of this thesis is as following.1. The calculate method of reliability index is perfected in order to improve calculate precision of structural reliability. A method of reliability analysis for composite laminate considering face and delamination failure is primary discussed. The safe margin according to conditional probability was given in order to provide theory basis reliability analysis under some condition.2. The influence by fatigue load on ultimate static-strength and stiffness of structural system is discussed, the paper gives expression of residual...