| With the continuous development of science and technology as well as industrial production, the machining industry has become increasingly large-scale and heavy-duty oriented. How to effectively handle the deformation problem of large-sized workpieces is a widespread concern. The VSR (vibratory stress relief) technique is widely applied in machinery industry because of namely applicability, low investment, less pollution and simple operation compared with natural aging and thermal aging. At present, the VSR technique has been widely used in our country. However, due to lack of systematic speculative knowledge when formulating vibration aging, the technological parameters were selected according to workers experience in production. Although workpieces have been treated through vibration ageing, it cannot well reflect the advantages of VSR technique relied only on worker's experience and subjectivity, so the residual stress was not effectively reduced. In this paper deals with the residual stress of large lathe bed, selecting vibratory parameters by means of finite element method. Starting with the engender deformation of casting residual stress,The article analyzed the microscopic and macroscopic mechanisms of vibration aging as well as its technological parameters. Then it proposed that the selecting of optimized processing parameters by finite-element analysis to improve vibration aging effects and production efficiency. During the research, the 3D finite element model of the lathe bed was established with the finite element analysis software. Then analysis of temperature field, stress field and deformation were done. The distributions of casting residual stress as well as the deformation status were derived. Subsequently, model analysis and harmonic responses analysis of workpieces were also conducted with the help of the dynamics analysis in ANSYS. Finally, by recurring to the result of thermal analysis, together with the model analysis and harmonic responses analysis, the vibratory parameter were selected.According to the result of finite element analysis, the experimental verification was carried out and the conclusive analysis of experimental result was done. The subject will better promote the application of the VSR technique in production practice for enterprises. |
