基于时变失效的桥式起重机结构可靠性分析

为提高我国起重机产品的安全可靠性水平,用时变可靠性理论分析桥式起重机金属结构。以桥式起重机金属结构为研究对象,时变可靠性理论为基础,研究桥式起重机金属结构的载荷时变可靠性模型和抗力时变可靠性模型,建立桥式起重机金属结构失效状态的时变可靠性数学模型。通过工程算例分析,揭示金属结构抗力随时间衰减与否对可靠度与失效概率的影响,得到不同金属结构抗力衰减系数下桥式起重机主梁金属结构可靠度和失效概率。探索桥式起重机金属结构时变可靠性安全评估方法。对比金属结构抗力衰减系数分别为0.000 2和0.000 3时的分析结果,发现金属结构系统的可靠性随金属结构抗力衰减系数的增加而降低。

Analysing Reliability of Bridge Crane Steel Structure Based on Time-varying Failure Theory

In order to improve the safety performance of the cranes and large machinery products,the bridge types of crane structure were analyzed by time-varying reliability theory.The crane bridge structure was regarded as the object of study.On the basis of the theory of time-varying reliability,load mathematical model and resistance mathematical model of bridge crane structure system were studied,and a reliability mathematical model of time-varying multi-failure state of the crane structure was built.Through analyzing engineering example,effects of the structural resistance decaying with time on the reliability and failure probability were observed,the bridge crane girder structural reliability and failure probability under the condition of different structure resistance attenuation coefficients were got.Methods for evaluating safety and reliability of bridge crane structure were worked out.The result is different when the attenuation coefficient is 0.000 2 from when the attenuation coefficient is 0.000 3.It was found that the reliability of structural system decreased with structural resistance attenuation coefficient increasing.