摘要
考虑超载的迟滞效应,对随机超载作用下的疲劳裂纹扩展进行了模拟计算.载荷谱为在基本恒幅循环载荷基础上加入一以泊松流发生的随机超载序列,超载的大小为均匀分布.采用裂纹闭合模型考虑超载的迟滞效应,认为裂纹张开应力在超载引起的塑性区内按线性规律衰减.循环续循环模拟计算出裂纹从初始长度一直到疲劳破坏的扩展曲线.据此,计算了各种超载发生强度和大小下的疲劳裂纹扩展寿命的平均值与标准差.
Monte Carlo simulation of fatigue crack growth under random overloads is presented. Overloads of Poisson flow with uniform distribution on base line constant amplitude cyclic loads are considered. The retardation effect of overload is taken into account using crack closure model and the crack opening stress level is assumed to vary linearly in the yield zone produced by the overload. The fatigue crack growth curve from initial crack size till fatigue failure is simulated step by step. The mean and standard deviation of fatigue lifetimes for various overload intensities and magnitudes are obtained.
出处
《固体力学学报》
CAS
CSCD
北大核心
2004年第4期476-478,共3页
Chinese Journal of Solid Mechanics
基金
教育部留学回国人员科研启动基金资助.
