Dynamic analysis on and optimized design of the BED structure of CNC machine

The dynamic characteristics of bed structure is a key factor in product performance, so to study how to improve the dynamic performance has profound significance to the development of machine tool. The simplified finite element modal is established with ANSYS aiming to study the machine tool bed, and the first 6-order natural frequencies and vibration models are selected to analyze. On the basis of the presented simulation analysis, the changing trend of the natural frequency is studied mainly while the height of bed in different circumstances. And the impact of ribbed plate of the spindle box supporting platform and the chip removal port structure on the dynamic characteristic are studied. With the work, effective solutions will be obtained and machine tool can be designed more effectively resulting in higher workpiece quality and process stability.

I. Introduction

THE commonly used method of dynamic optimization of machine tool bed and other complex system of mechanical structure is geometry optimization. That is the way of human-computer interaction by using modeling, performance analysis and the modifications according to the design requirements of structure. And then analyze repeatedly until the mechanical dynamic performance can meet the requirements. This is a re-design changing to the process of re-analysis [1]–[3]. To achieve optimization of dynamic performance of machine tool bed, domestic and foreign scholars have done a lot of research work. Xu Yanshen took the theory of elementary structure to discuss and analyze the machine tool bed, then the optimize structures were obtained [4]. Improving the type and layout of rib as an effective way to enhance the static and dynamic characteristics of the bed was presented by Ji Guowei [5]. Chenxin showed that taking the natural frequency and vibration displacement as evaluation criteria for grinding lathe bed's dynamic optimization [6].