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为了定量评估含广布腐蚀损伤老龄化飞机结构的剩余强度,采用等效裂纹方法将腐蚀坑沿垂直于外界最大主应力方向进行投影处理,使其转化为具有相同寿命的等效初始表面裂纹,然后采用参数化有限元方法,求解等效裂纹前沿的应力强度因子、裂纹扩展方向和裂纹扩展增量,建立并应用应力强度因子变化历程,采用循环接循环的损伤累积方法对含广布等效表面裂纹在疲劳载荷作用下的寿命进行了预测.预测结果为复杂环境中含广布腐蚀坑的飞机结构寿命预测提供了参考.
In order to quantitatively evaluate the residual strength of the aging aircraft structure with a wide range of corrosion damage, equivalent pitting method is used to project the corrosion pits perpendicular to the direction of the maximum principal stress of the outside world so as to transform them into equivalent initial surface cracks with the same life, Then, using the parametric finite element method, the stress intensity factor, crack propagation direction and crack growth increment at the equivalent crack front are solved, and the change course of the stress intensity factor is established and applied. The life expectancy of the surface crack under the fatigue load was predicted.The prediction results provided a reference for the prediction of the life expectancy of aircraft structures with a wide range of corrosion pits in complex environment.