焊接结构疲劳性能仿真实验研究

分析目前焊接结构的研究状况,采用断裂力学的方法,对焊接结构疲劳性能进行评估,通过求解裂纹前缘应力强度因子,确定裂纹前缘的扩展速率,从而对焊接结构进行裂纹扩展实验。建立焊接结构的疲劳裂纹模型与裂纹前缘的奇异单元模型,实现仿真实验。发现不同的初始裂纹对焊接结构的疲劳寿命有着不同的影响,形状比大的裂纹扩展相对较快;应力强度因子随着裂纹的扩展有逐渐变大的趋势,但是变化逐渐缓慢。

Fatigue Performance Emulation Research of Weld Structure

This paper analysis the weld structure research condition,and carry on the appraisal of weld structure fatigue performance with the method of fracture mechanics.The crack expansion rate is confirmed by solution stress intensity factor of crack front,and then the crack expansion experiment of weld structure is carried on by method above.This paper establish weld structure fatigue crack model and crack front singular unit model to carry on simulation experiment.The rule of different initial crack geometry shape has different influence is discovered,the big geometry shape,the quick crack growth.The stress intensity factor is bigger as the crack expansion,but changes gradually slowly.