龙门加工中心动态特性的有限元模态分析与结构优化

为了改善某龙门加工中心的动态特性，对龙门加工中心各主要结合部进行等效处理，建立了龙门加工中心整机有限元模型，对其整机进行模态分析，确定了整机动态性能的薄弱环节。针对滑枕导轨结合部刚度不足提出了2种改进方案，通过整机的有限元模态分析和固有频率的比较，得出采用高刚度的导轨滑块副作为滑枕导轨优选方案。在此基础上针对滑枕抗弯刚度不足提出了3种结构改进方案，再次通过整机的有限元模态分析和固有频率的比较，最终选出了龙门加工中心结构动态特性的最优改进方案。研究表明：机床整机结构的模态分析与结构优选是提高机床动态性能的有效手段。

Finite Element Modal Analysis and Structural Optimization of Dynamic Characteristics of Gantry Machining Center

In order to improve the dynamic characteristics of gantry machining center, the finite element model of the machining center was built after equivalent processing of main joint of the gantry machining center. The weak parts of the gantry machining center were confirmed by model analysis of the whole machine. Two improved schemes were given to improve the stiffness of the joint of the sliding pillow and guide rail. Through model analysis and comparison of natural frequencies. the scheme which used higher rigid guide pillow was selected. Based on the improved scheme. another three improved schemes were proposed to improve the stiffness of ram, finally the best scheme was chosen through model analysis results. It shows that the modal analysis of machine tool structure and structural optimization are effective means for improving dynamic performance of machine tool.