程晓章 ，束开金，魏明，余昳，周平

(合肥工业大学 机械与汽车学院，安徽 合肥 230009)

摘要：以柴油机发动机曲轴为研究对象，运用CATIA建立发动机曲轴三维几何模型，并运用ABAQUS有限元分析软件对发动机曲轴进行了自由模态分析。再对曲轴的细节特征和约束进行了简化，求出了曲轴自由约束条件下前七阶模态的固有频率和振型。运用实验对比分析方法，通过模态实验可获得曲轴各阶的模态频率和振型，为动力分析提供技术参数，同时也为进一步发动机高速运转时曲轴振动中危险各区域提供了理论依据。

关键字：曲轴;模态试验;频率;振型

Abstract: Researches on the engine crankshafts were carried out.We establish the 3D geometric model of engine crankshafts using CATIA and did free modal analyses of engine crankshafts using ABAQUS  finite element analysis software. The detailed characteristics of crankshafts and constraints were simplified. The model frequencies and vibration formation of crankshafts under free constraint conditions in the first seven orders were calculated, which provided technical parameters for the dynamic analysis as well as a theory basis.

Key Words: Crankshaft； Modal Test；Frequency； Vibration Formation