杆系结构静强度和疲劳失效机理及可靠性分析

FAILURE THEORY AND RELIABILITY ANALYSIS OF TRUSS STRUCTURES CONSIDERING STATIC STRENGTH AND FATIGUE

根据疲劳载荷造成的疲劳累积损伤对结构极限承载力的影响情况,讨论了结构系统承载能力的可靠度计算方法,分析了结构系统中每一个单元在静载和疲劳载荷作用下的两种失效模式,并考虑了二者之间的相关性对该单元可靠性的影响,具体分析了结构系统在这两种载荷作用下的失效机理,给出了在这两种载荷作用下结构系统的可靠性分析方法.算例表明,在不同的使用年限内,静载和疲劳载荷对结构系统可靠性的影响是不同的;在结构系统主要失效路径中既有单元静强度失效又有单元疲劳失效,这是符合结构系统使用真实情况的.

The elements of structural system subjected to dead and fatigue load will be dead or fatigue load failure by any possibility. Based on the understanding of passive impact of accumulated damage induced by fatigue load on ultimate bearing capacity, the ultimate bearing capacity reliability analysis method for structures subjected to fatigue load was presented. The paper analyzed dead or fatigue load failure of every element of structural system and considered the relativity of two failure modes influencing on the element reliability. The paper discussed the failure theory of structural system subjected to dead and fatigue load and gave 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 the different using state, the failure forms of elements in the significant failure paths have dead and fatigue load failure. It is suitable for engineering case.