论文部分内容阅读
通过对正火４５钢的试验数据分析，提出了一个反映剩余强度退化的对数表达式，给出对称恒幅应力循环下疲劳损伤的定义与表达式。该表达式能够反映损伤演化的非线性特性。进一步分析了随机应力循环下结构的疲劳损伤，导出损伤演化的递推公式，并结合大量的计算给出结构在应力块重复循环下疲劳寿命估算的一个近似方法。
By analyzing the experimental data of normalized 45 steel, a logarithmic expression reflecting the residual strength degradation is proposed, and the definition and expression of fatigue damage under the symmetrical constant amplitude stress cycle are given. The expression can reflect the nonlinear characteristics of damage evolution. The fatigue damage of the structure under random stress cycles is further analyzed, and the recursion formula of damage evolution is deduced. Combining with a large number of calculations, an approximate method for estimating the fatigue life of the structure under repeated stress cycles is given.