摘要
运用LEFM与EPFM理论,利用计算机编程,对TSG450×800榨机辊轴上各种形式裂纹在危险截面上的临界裂纹尺寸进行了计算,同时,进行了该轴的剩余寿命计算与安全评定.其中,着重研究了轴表面横向半椭圆裂纹问题,通过三维光弹方法找出了b/α=0.87与0.40两种深长比的SIF修正系数M及其沿裂纹前缘的分布,从而求出轴表面横向半椭圆裂纹的SIF K_Ⅰ,K_Ⅱ与K_Ⅲ.这一成果,对目前尚无理论解的轴表面横向半椭圆裂纹的SIF求解有一定的参考意义.对工程上类似的辊轴,只要具备一定准确性的探伤资料,在本文讨论的范围内,可进行安全评定.
Based on the theory of LEFM and EPFM, the measurement of critical cracks and residual lives of various kinds of cracks at the dangerous cross sections on the roller shaft of the TSG 450×800 sugar press are calculated via computer programming and the safety evalutions are carried out. The semi-elliptic transverse surface crack of the shaft is studied as the key-point.The correction parameters of the SIF for two kinds of depth/length ratios(i.e.b/a=0.40 and 0.78) and their distribution along the front of the cracks are obtained by means of the 3-D pheto-elastic method, so the SIF(K_Ⅰ,K_Ⅱ,K_Ⅲ) of the semi-elliptic transverse surface cracks are found. The result shows that the safety evaluation can be carried through for the similar roller shaft in engineering as long as comparatively accurate NDE record is obtained and can be taken into consideration in the experimental research of the semi-elliptic transverse surface crack for which there is not any theoretical solution so far.
关键词
榨糖机
辊轴
寿命
断裂力学
Damage tolerance assessments
Fracture mechanics applications
Surface cracks
Semi-el liptical cracks
