考虑剩余强度的焊接箱形梁动态可靠性分析

摘要

Aiming at current analysis on metal structure of crane which does not reflects the dynamic change of reliability with time, in consideration of reliability and failure rate changing with time due to multilevel cyclic stress of varying amplitude, the paper deduces calculation formula for dynamic reliability of metal structure.The analysis shows that the reliability of metal structure may be affected by stress cycles, peak stress and residual intensity, and reduces in a nonlinearity way over time.The analysis lays a theoretical foundation for life evaluation and dynamic monitoring of the crane and has important practical value in engineering.%针对目前起重机金属结构可靠性的研究未反映出可靠度随时间动态变化的特性,考察其可靠度和失效率受多级的变幅载荷影响随时间的变化过程,推导出起重机金属结构的动态可靠度计算公式.研究表明:起重机金属结构的可靠度受到应力作用次数、应力峰值和剩余强度等因素的影响,并随时间的增加而呈非线性降低的特性.本研究为起重机的寿命评估和动态监测奠定了理论基础,具有重要的工程实用价值.