曲轴轴承座裂解槽参数对裂尖应力应变场的影响

裂解技术的核心问题是人为构造缺口,在缺口处形成应力集中,产生初始裂纹源,裂纹扩展直至最终断裂。本研究以某轿车曲轴轴承座为研究对象,利用解理断裂正应力判据作为理论依据,运用断裂力学软件Abaqus模拟分析了不同缺口参数下,裂解前裂尖处的应力应变场。通过模拟分析,研究裂解缺口参数对解理断裂判据中各参量值的影响。分析结果表明:曲轴轴承座材料QT500常温呈脆性,缺口不敏感;鉴于裂解中要考虑裂纹形核、扩展、缺口加工及裂解载荷等问题,初步确定了曲轴轴承座裂解槽的优化参数。经试验验证,缺口参数优化后获得了理想的裂解效果。

Influence of Cracking Groove Parameter of Crankshaft Bearing Block on Crack Tip Stress-strain Field

The core of fracture splitting process was building the gap artificially.The stress concentration formed in the gap and then the initial crack generated,extended and finally ended with the fracture splitting.Taking a car crankshaft bearing block as research object,the stress-strain field of crack tip before fracturing was analyzed under different gap parameters with Abaqus software based on the criterion of cleavage fracture normal stress.The results showed that the gap was insensitive because QT500 cylinder block behaved brittle at normal temperature.Considering the problems of crack nucleation,extending,splitting groove machining and splitting load,the optimum parameters of cracking groove were determined.The experiment proved that the optimized parameters had a good effect of fracturing.