杆身截面积减小对连杆屈曲的影响

以某非道路四缸高压共轨柴油连杆为研究对象,采用由多体动力学与有限元分析结合的方法,研究了工字型杆身截面积参数变化对连杆整体屈服、疲劳安全系数和屈曲的影响规律。结果表明,杆身截面的宽度和厚度参数变化对连杆疲劳安全系数影响最敏感,其次是屈曲。厚度参数变化对连杆屈曲和疲劳安全系数的灵敏度影响相近。当杆身截面横截面积减少率相同时,厚度方向参数变化对屈曲的影响大于宽度方向参数变化对屈曲的影响。因此,在杆身截面参数选择设计和优化时,不宜过多减小厚度参数,可考虑减少宽度方向参数。

Influence of Reduction of Shaft Section on Buckling of Connecting Rod

A non-road four-cylinder high-pressure common rail diesel connecting rod is taken as the research object.The multibody dynamics analysis method and orthogonal experimental design method were used to study the influence of the variation of the cross-sectional area of the I-shaped shaft on the overall yield,fatigue safety factor and buckling of the connecting rod.As a result,the variation of the width and thickness parameters of the shaft section is most sensitive to the fatigue safety factor of the connecting rod,followed by buckling.The change of thickness parameter has similar effects on the sensitivity of the buckling and fatigue safety factor of the connecting rod.When the cross-sectional area reduction rate of the shaft is the same,the influence of the change of the thickness direction parameter on the buckling is greater than the influence of the parameter change of the width direction on the buckling.Therefore,when designing and optimizing the shaft section parameters,it is not advisable to reduce the thickness parameter too much,and it is considered to reduce the width direction parameter.