摘要
采用随机裂纹扩展模型对高耸结构的风振疲劳问题进行分析,同时考虑平均风速的概率分布和时间相关性对裂纹扩展的影响,用ZMNL法模拟相关的平均风速时程样本,根据Monte-Carlo法得出裂纹长度的概率分布。推导出计算裂纹长度和疲劳寿命的二次矩近似法公式,用对数正态模型近似计算其概率分布。通过对一单杆输电塔的计算,证明上述方法的可行性,并对时间相关性对裂纹扩展的影响进行分析。
A stochastic crack growth model of high-rise structures under wind loading was analyzed in the paper. The probability distribution and time relativity of mean wind velocity were taken into account. The time series of mean wind velocity were simulated by zero memory nonlinearity method, and the probability distribution of crack length was calculated by Monte-Carlo method. The equations of second-order moment method were derived, and distribution of crack length and reached time was approximated by lognormal model. The feasibility of this method was proved by calculation of a single-rod transmission tower. Finally, the influence of time relativity to the crack growth were analysed.
出处
《钢结构》
2007年第8期43-47,共5页
Steel Construction
