【摘要】 为详细考察含裂纹平板在不同初始裂纹参数下的应力强度因子变化规律以及平板在激振工况下的疲劳裂纹扩展寿命，利用子模型技术建立含不同初始裂纹的平板有限元模型，采用M-积分计算前缘面的应力强度因子，基于Paris公式计算平板在不同应力比下的疲劳寿命。结果表明：平板在工况下的破坏以I型裂纹为主，改变初始裂纹形状、尺寸与预埋深度不会影响裂纹类型；初始裂纹形状变化会影响初始前缘面应力强度因子的分布规律与均衡性，半椭圆形裂纹应力强度因子分布不均衡性更显著，而半圆形裂纹则较均衡，K₁值分布规律呈V字形和1/4弧形；初始裂纹预埋越深，起始前缘应力强度因子越大，裂纹扩展驱动力越高；初始裂纹倾斜角度改变，裂纹类型会发生变化；以裂纹穿透工字梁危险处板厚为疲劳失效判断时，裂纹扩展至15.151 4 mm;三种应力比工况下的平均疲劳寿命与现场统计结果的误差为13.17%。上述分析为可控震源平板的裂纹失效问题与疲劳优化设计提供了参考，具有一定的工程意义。更多还原

【Abstract】 In order to investigate the variation of the stress intensity factor of a cracked baseplate under different initial cracking parameters and the fatigue crack growth life of the baseplate under vibration excitation working condition, the finite element model of the baseplate containing different initial cracks was established by using the sub-modeling technique, and the stress intensity factor of the leading edge surface was calculated by the M-integral, and then the fatigue life of the baseplates with different stress ratios was calculated based on the Paris formula. The results show that the damage of baseplates under working conditions is dominated by type I cracks, and changing the initial crack shape, size and pre-embedding depth does not affect the crack type. Initial crack shape variation affects the distribution pattern and balance of the stress intensity factor at the starting leading edge, and the unevenness of stress intensity factor distribution is more significant for semi-elliptical cracks, while it is more balanced for semi-circular cracks, their K₁ values are V-shaped and 1/4-arc respectively. The deeper the initial crack pre-burial is, the higher the stress intensity factor at the starting leading edge and the higher the crack extension driving force. The crack type changes when the initial crack tilt angle is changed. When fatigue failure is judged by crack penetration through the plate thickness at the I-beam hazard, the crack extends to 15.151 4 mm. The error between the average predicted fatigue life under three stress ratios and the field statistical results is 13.17%. The above analysis provides a reference for the crack failure mechanism and fatigue optimization design of the vibrator baseplate, and has certain engineering significance.更多还原