连杆裂断力参数的数值分析及其裂断质量研究

针对基于连杆裂断时所需裂断力的问题,利用断裂力学理论及有限元方法,采用KIC判据对与拉杆位移、裂断力及应力强度因子KI三者关系展开了研究。通过数值分析求解了应力强度因子达到断裂韧性KIC时拉杆所需的位移,以确定拉杆提供的裂断力。理论分析结果显示:裂纹槽宽为0.2 mm、槽深为0.4 mm的BYD473连杆,拉杆在位移27.25 mm处,连杆应力强度因KI达到断裂韧性KIC,此时连杆裂断所需的裂断力为32.75 kN,拉杆裂断力与应力强度因子KI呈线性关系。采用实验的方法分析了连杆裂断所需的裂断力及连杆的裂断质量。研究结果表明,连杆裂断时,所需的裂断力为32.75 kN,连杆裂断质量良好。数值分析与裂断实验数据对比结果显示,数值分析误差为11.4%,数值分析结果良好,可为液压系统参数的确定提供理论依据。

Numerical analysis on splitting process and research on splitting quality for connecting rod

Aiming at the problem of calculating the fracture splitting force based on the fracture of connecting rod, fracture mechanics theory and finite element method was applied. The relationships of the fracture splitting force, stress intensity factor stress KI and bar displacement were researched based on KIC criterion. The fracture splitting force was calculated since KI reached fracture toughness through finite element method. The results indicate that the fracture splitting force is 32.75 kN while connecting rod splitting and the linear relationship is shown for the connecting rod which crack width 0.2 mm and depth is 0.4 mm. Meanwhile, the fracture splitting force was inquired by experiment. The result indicates that it is 32.75 kN and has a good quality. Compared numeral analysis with experiment, its error is 11.4%. The result provides theoretical basis for hydraulic system parameters.