铝合金板广布损伤裂纹扩展顺序的数值分析

在三排45孔铝合金板广布疲劳损伤试验基础上,对模型进行了有限元计算,系统研究了广布损伤裂纹尖端相互影响因子分布和裂纹扩展顺序规律。结果表明:裂纹尖端相互影响因子βi,当受两个裂纹参数ai和aj影响时,其随着aj的增加而增加,随着ai的增加而减小;当受三个参数ai、aj和ak影响时,其随着aj和ak的增加而增加,随着ai的增加而减小。循环数N相等时,模式I扩展最快,模式II最慢,模式III的扩展间于模式I模式II之间,但比较接近模式II,这是由于模式III下孔裂纹比较接近于模型中间位置,受模型边界的影响较小。以上结论表明,在实际工程应用中,多裂纹出现在模型中间要比靠近边界安全。

Numerical Analys is on Crack Propagation Order of Widespread Damage in Aluminum Alloy Panel

Based on the three rows of 45-hole widespread fatigue damage experiments of aluminum alloy panel,the accurate finite element models were established and calculated .The interaction factor near the crack front of widespread fatigue damage and the crack propagation order were analyzed systematically . The results indicate that the interation factor βi increases with the increasing aj and decreasing ai for 2 variable factors,while decreases with the decreasing aj,ak and increasing ai for 3 variable factors.It is al-so indicated that when the cycles N is equal,the crack of mode Ⅰ grows fast while the crack of mode Ⅱ grows slow .The crack of mode Ⅲ grows between the two mentioned above ,and is more close to mode Ⅱ due to the location near the center of the model .Conclusively ,in actual engineering application ,it is safer when the multiple cracks appear near the center of the model than near the border of the border .