船用柴油机机体组合结构模态分析方法

摘要

利用数值试验方法验证包括柴油机机座、机架、气缸体、扫气箱、空冷器等有限元模型简化的合理性.通过螺栓连接板件的模态试验验证有限元法模态分析中螺栓连接处理方法的可靠性.在此基础上建立包括以上各部件的某大型船用6缸柴油机机体组合结构有限元模型.通过对整体结构模态分析,找出整机刚度局部薄弱部位和整体固有振型.为大型船用柴油机设计人员在设计阶段,预报和预防整体结构振动提供一较为简便的方法.%The simplified finite element models of base, frame, cylinder's body, scavenge box, and air cooler of a diesel engine were established and validated by numerical simulation respectively. Treatment method of bolt-connection in the finite element analysis (FEA) was verified by the results modal testing of bolted plates. Based on these, the finite element model of the combination structure of a 6-cylinder diesel engine was built. Weak parts and the modals of whole engine were found through modal analysis. A simple approach for prediction and reduction of engine structure' s vibration was proposed.