DDZ5—18—350牛头钻杆吊卡断裂分析

对ＤＤＺ５－１８－３５０牛头钻杆吊卡三维应力场进行分析后，采用有限元位移法，求解危险截面处不同深度和形态表面角裂纹的应力强度因子，给出了应力强度因子沿裂纹前沿的变化规律。根据有限元数值，拟合出关于角裂纹特征参数的无量纲应力强度因子表达式，为预测带裂纹的牛头钻杆吊卡的承载能力、剩余寿命、确定探伤周期和制定判废标准等提供了必要的断裂分析参数。

Fracture analysis of a center-latch type drill pipe elevator

After an analysis of the 3-D stress field on a Model DDZ5-18-350 center-latch type drill pipe elevator,the stress-intensity factors (SIFs) of the surface comer crack with different depths and shapes on the critical section are worked out by the finite element displacement method, and the pattern of variation of SIFs along the front of the crack is presented. On the basis of the numerical values obtained, the expressions for calculating SIFs by the characteristic parameters of the comer crack are derived, providing a basis for predicting die load capacity and residual life of an elevator with crack, determining the period of flaw detection, and laying down the code of abandonment.