Abstract: Based on the understanding of passive impact of crack induced by fatigue load on ultimate stress and section module, the paper gives the expression of residual resistance, analyzes the dead or fatigue load failure of every element of structural system and considers the relativity of every failure modes influencing on the element reliability. The paper discusses the failure mechanism of structural system subjected to dead and fatigue load and gives the method of reliability analysis considering static strength and fatigue. A numerical example is analyzed. It is indicated that the influence on the structural system by dead and fatigue load is different at different application states. The failure forms of elements in the significant failure paths have dead and fatigue load failure. It is suitable for engineering case.

Key words: structural system reliability, dead failure, fatigue failure, failure mechanism, relativity