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前言如所周知,在金属材料中总是存在着各种导致裂纹的因素,如夹杂、脆性的粒子、沿晶界分布的脆性相析出物、以及由于各种原因导致的应力集中等等(这类情况在大锻件中尤其严重)。在工作中,这些地方极易产生裂纹,有了裂纹的零件还能不能用?还能使用多久?这些问题只有通过断裂力学分析才能解决。在进行断裂力学分析时,首先必须算出承载零件的临近裂纹尖端处的应力强度因子K,并通过材料的断裂力学试验测出零件材料的临界应力强度因子K_c。若K>K_c,则
Preface As we all know, there are always a variety of factors that lead to cracks in metal materials, such as inclusions, brittle particles, brittle phase precipitates along grain boundaries, stress concentration due to various reasons, etc. In the case of large forgings in particular). In the work, these places are easy to crack, the cracked parts can not be used? Can also be used for how long? These problems can only be solved by fracture mechanics analysis. In the fracture mechanics analysis, we must first calculate the load-bearing parts near the crack tip of the stress intensity factor K, and through the material fracture mechanics test to determine the critical material strength stress factor K_c. If K> K_c, then