Finite Element Analysis Of Heavy-duty Machine Tool Structure

At present machine tool industry of home has problems of machining accuracy, treatment technology, processing factory and so on. All these problems limit the development of the industry. Fortunately, finite element method (FEM), which has been widely used in machine tool industry in recent years, provides strong support to improve the equipment industrial level. In this paper, the static and dynamic properties of a kind of High Performance Roll Leveler are studied by the ways of FEM overall modeling, Vibratory Stress Relief, Blind Hole Method and so on. All the reassures provide reference and support to make out stress and strain situation of the machine tool, chose reasonable treatment technology and optimize the structure.There are three FEM models in the article. The first model, which is built for analysis the statics under limit load, is entire structure model of the roll lever. The third model is a plane model as a simulation to the third model. And the third model, which is used in the modal analysis, is the machine tool body model.From the analysis of the three models with statics, dynamics, modality, harmonic response analysis and VSR theories, the research findings are:1, Based on static theories, the strength and deformation of the overall structure are studied. The results indicate that the stress level and deformation are in a reasonable range. However, there's room for improvement.2, Based on static theories and contact theory, the key component to bear loads is studied. The results indicate that the local structure, which is improper, will lead to high stress situations happen in the key component. It's necessary to perfect the structure to homogenize the stress.3, Analysis the machine tool body model and flat plan simulation model with modal analysis theory to find out the difference of the two structures. We find the machine tool body structure has more complex modal characteristics which may play a negative role in carrying on the VSR.4, Use harmonic analysis theory to evaluate effect of Vibratory Stress Relief. We find compared with plan simulation structure, the machine tool body structure has lower overall dynamic stress and more obvious stress concentration. All these results mean this kind of box-type structure is not suitable for VSR.5, Use Blind Hole Method testing welding residual stress to confirm the conclusion of theoretical analysis. The testing results also confirm that the residual stress of machine tool body structure is not obvious improved. We know from the research that the VSR is not suitable for the structure such as the machine tool body.The research proves that it's possible to analysis the machine tool structure by overall modeling with FEM software. From the FEM analysis we can get the statics and dynamics properties of complex machine tool structure. It gives us a good way to improve machining accuracy and throughput of the large size machine tool.