爆炸自紧残余应力及对构件疲劳强度的影响

用贴腻子炸药法和动液压法两种爆轰工艺对不同类型厚壁构件实施了爆炸自增强处理，并对爆炸处理形成的残余应力进行了实验测定。对内壁有缺口和裂缝的厚壁圆环以及带缺口的超高压圆筒和四通构件进行了爆炸自紧处理并进行了疲劳实验检验，结果是:在高周疲劳阶段，经爆炸处理的构件缺口根部疲劳裂纹萌生寿命可提高5倍，内压疲劳开裂寿命可提高8~10倍。在低周塑性疲劳阶段构件的疲劳开裂寿命仍可提高1倍左右。由于用贴腻子炸药方法可使构件表面硬度增加从而获得更高的残余压应力，故其自增强效果优于动液压法。

The residual stress and its influence on the fatigue strength induced by explosive autofrettage

With two different explosion methods, different super-high pressure components were auto- frettaged, one is the dynamic liquid explosion, the other is sticking oily explosion. The super-high pressure component includes thick wall circles with a crack or notch on the inner wall, super-high pressure thick wall cylinders and fours-ways were chosen to conduct autofrettage. The residual stress was measured, and then the fatigue test was carried out. The test results show that the fatigue initia- tion life Nican be increased by 5 times, the fatigue progress life Nfcan be increased by 8~10 times in the high cycle fatigue period. In the low cycle plastic fatigue period, the fatigue progress life Nfcan al- so be increased by 1 time. The sticking oily explosion is better than the dynamic liquid explosion be- cause of the increasing of the rigidity of the surface.