Reliability Analysis Of Structural Systems With Multiple Failure Modes

Present, it is generally recognized that many structural systems are indeterminate. For example, 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. Therefore, it is necessary to make stochastic analysis of structural systems and to evaluate its reliability.It is possible that many failure modes have emergence during the structural service period. For example, dead load strength failure, stiffness failure and fatigue failure. However 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 ocean engineering structures. At first, small wave load have caused an amount of damage and decrease the ultimate bearing capability to the structures, then fatigue load have caused wholly destroy. In the other hand, these failure modes have relativity for some parameter. Therefore, reliability analyses of structural systems must simultaneity consider 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 fatigue load applied on the structure would have some damage and decrease the ultimate bearing capability to the structure. Thus, reliability analysis must consider it during structure wholly service period. This thesis discussed reliability analysis method of structural system that simultaneously considered the fatigue load and the dead load. This method considered relativity of two failure modes and could make scientific theory of structural systems inspected and maintained.2. The reliability analysis method of incomplete structure stiffness is proposed in this thesis and failure probability of this could be computed in the each failure process. This method made the theory basis of incomplete structure that could keep serving with economic or reasonable and maintain program.3. The reliability analysis method of incomplete structure strength and stiffness is proposed in this thesis and failure probability during each failure process is obtained. This method proposed theory basis to designer who could realize reliability during each failure period and to improve design.4. Reliability of structural systems was analyzed with multiple failure modes and discussed every failure mode effect systemic failure probability. This method made the basis to improve structure design and optimize structure.