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将结构体系中不确定参数定义为区间变量,在随机疲劳谱分析方法的基础上,提出一种计算平稳高斯荷载作用下不确定结构疲劳损伤的新方法。该方法采用区间参数模型定义结构的不确定性,应用功率谱密度描述外荷载的随机性;利用有理级数和单位对称区间显式表达结构区间频响函数和不确定结构在平稳高斯荷载作用下的动力响应区间;根据Tovo-Benasciutti疲劳损伤预测模型,计算不确定结构在随机荷载作用下的疲劳损伤区间期望率;并可通过调整相应不确定参数的单位对称区间近似估计该不确定参数不同不确定半径的疲劳损伤区间期望率。通过数值算例,将该文提出的随机疲劳区间分析方法与顶点法进行比较,验证了该方法的准确性和适用性。
Based on the stochastic fatigue spectrum analysis method, a new method to calculate the fatigue damage of uncertain structures under steady Gaussian load is proposed. The method uses the interval parameter model to define the structural uncertainty. The power spectral density is used to describe the randomness of the external load. The rational frequency range and the unit symmetry interval are used to express the structural frequency response function and the uncertain structure under the steady Gaussian load According to the prediction model of Tovo-Benasciutti’s fatigue damage, the expected rate of fatigue damage in uncertain structures under random loading is calculated, and the uncertainty parameter can be approximated by adjusting the unit symmetry interval of corresponding uncertain parameters Determine the expected rate of fatigue damage zone radius. A numerical example is given to compare the stochastic fatigue analysis method with the vertex method proposed in this paper, which verifies the accuracy and applicability of the method.