基于多体动力学的连杆强度分析

The Strength Analysis of Connecting Rod Based on Multi-body Dynamics

连杆作为发动机最重要的零部件之一,工作过程中受急剧变化的动载荷影响,容易发生断裂失效,必须具有较高的强度和可靠性。采用多体动力学仿真进行边界条件求解,确定连杆的最大压载荷和最大拉载荷,在此基础上进行静强度计算得到三个工况下的应力分布,计算出危险截面的安全系数。分析结果表明连杆在4000 r/min时承受载荷最大,在此工况下应力集中截面为连杆小头与杆身过渡处、连杆大头与杆身过渡处、油孔及小头孔内部下半部分,最大应力值为641Mpa,在材料许用应力范围内。几个危险截面中安全系数最小为1.34,设计安全,并具有一定的强度储备。

Connecting rod is one of the most important parts of engine, and it works under a sharp change of dynamic load, which makes it easy to fracture failure, it is very serious. Therefore, connecting rod must have high strength and reliability. This article adopts the method of multi-body dynamics, to determine the maximum compression conditions and the maximum tensile conditions, and calculate safety factor of several dangerous section. The results show that the maximum force is at 4000rpm, and the concentration section appears at the transition area for big end of connecting rod and shaft, small end of connecting rod and shaft, the lower half of the oil hole and small end. Maximum stress value is 641Mpa, it is under the range of allowable stress value. The minimum safety factor is 1.34 in the several dangerous section, the design has some strength reserve.