有限元法在机械结构模态分析中的应用

Application of finite element method in modal analysis of machine structure

运用有限元法对机械结构进行模态分析可以求出结构的固有振动特性,获得避免共振现象产生的工作频率范围,同时提出改善结构模态特性的方法。文章运用有限元分析软件ANSYS分析了某机床床身的前8阶固有频率和振型,提出了适合加工的主轴转速范围和改善床身结构模态特性的方法。研究实例表明:有限元法具有简单、快速、直观的特点,是一种对机械结构进行模态分析的有效方法。

The natural vibration characteristics of machine structure can be obtained by modal analysis using finite element method. The results will guide us to select the range of working frequency far away from sympathetic vibration and to put forward the method for improving modal characteristics of structure. The first eight natural frequency and vibration modes of the body of a machine tool are analyzed by using the finite element analysis software ANSYS. The speed of mainshaft in machining condition and the method for improving modal characteristics of machine structure are carried out. The study example shows that the finite element method is an efficiency method for modal analysis of machine structure with its advantages of simpleness, speediness and direct-viewing.