柴油机曲轴连杆组合结构动态特性分析

以康明斯6BT5.9柴油机曲轴连杆组合结构为研究对象,采用试验模态分析和有限元理论分析相结合的方法得到其动态特性,进而改善动力性能,降低振动强度,优化结构设计.在进行有限元理论分析时,分别采用耦合自由度法、弹簧-阻尼单元联接法、虚拟材料法模拟曲轴连杆的边界联接方式.对试验模态分析法与理论模态分析法所得到的模态参数采用频率准则进行相关性分析,可以看出弹簧-阻尼单元联接法、虚拟材料法得到的计算值与试验值相关性更高,即这两种方法在结合面接触处理上更合理,为柴油机整机动态分析及优化设计提供了理论依据.

Dynamic Characteristics of Crankshaft-Connecting Rod of Diesel Engine

The dynamic characteristics of crankshaft-connecting rod of the Cummins 6BT5.9 diesel engine were studied using a combined method of experimental modal and finite element analysis to optimize the dynamic performance, intensity of vibration and structure design. In the finite element analysis, the boundary conditions of combined structure were simulated by methods of coupled degrees of freedom, spring-damper unit connection and virtual material, respectively. Frequency criteria was then used to investigate the correlation analysis of the modal parameters obtained. It shows that the correlation between the calculated and experimental parameters by spring-damper unit connection and virtual material method is higher, which are more reasonable in dealing with the joint surface contact. It provides a theoretical basis for dynamic analysis and optimization design of diesel engine.