螺纹连接是柴油机中应用最普遍的连接方式,影响到柴油机结构的动态特性。为了研究考虑螺纹连接时柴油机抗冲击特性,设计加工了一个机脚螺纹连接试验件进行模态试验,并引入梁-弹簧单元进行螺纹连接有限元建模,试验结果与有限元分析结果误差小于5.4%,验证了螺纹连接建模方法的正确性。采用动态设计分析法(DDAM)对柴油机固定件进行冲击响应分析,对3个方向的冲击应力响应结果进行相位耦合,校核了各部件的冲击安全性。结果表明应更换高屈服强度极限的机脚材料,而机脚螺纹连接符合GJB 1060要求。在柴油机抗冲击研究中采用该种螺纹连接模型可以得到更真实的结果。

The bolt connection is one of the most common connection methods applied in a diesel engine. It will affect the dynamic characteristics of the diesel engine's structure．A test model of the machine foot bolt connection is prepared to study the shock resistant characteristics of the bolt connection in the diesel engine. The screw-thread connection model of the beam - spring unit is introduced into the experiment to build the finite element model. A difference less than 5.4% is shown by comparing the results of the test model and the finite element analysis, which has verified the feasibility of the modeling method. With the DDAM (Dynamic Design Analysis Method), the impact safety of all components is verified by analyzing the shock response of the diesel engine's fastened components and phase-coupling the shock stress' response results in three directions. The experiments show that the material of the diesel engine feet should be replaced by one with a higher yield limit, while the machine foot bolts satisfy the national military standard requirements. The bolt connection model is shown to provide realistic results in the diesel engine shock resistance study.