A Study Of Forming Limit In Multi-pass Conventional Spinning And Multi-objective Optimizationof Its Spinning Deformation Quantity Distribution

Spinning is a kind of typical plastic forming technology in Precision metal processing field, which is widely used in the manufacturing of high quality and precision products because of its performance improvement, accurate forming and principle of chipless. However, spinning is continuous local plastic deformation, which is difficult to control the shape precision and dimensions of molded parts. Especially for processing thin-walled, high thickness difference demanding rotary parts, it is difficult to spin in one pass, and multi-pass spinning is needed to improve the forming quality and forming limit of work piece. In this thesis, A multi-pass conventional finite element model which contains the springback compensation is established, and processing limit and pass spinning deformation quantity(SDQ) that influence the forming quality will be investigated, in order to reveal the distribution of multi-pass conventional spinning deformation quantity with Gray relational analysis.Build analysis models for the forming process and springback process in multi-pass conventional spinning by utilizing the finite element method and the related software (ansys/ls-dyna).And based on the overall springback data after spinning, making springback compensation to the multi-pass conventional spinning paths.Tons of model data, such as forces, stress and strain data through lots of numerical experiments are obtained in order to analysis the forming defects of multi-pass conventional spinning, which contains crack, unstability of the flange and excessive thinning. Delve into the multi-pass conventional spinning forming limit, thereby obtaining each pass limit quantity of SDQ, provide a basis for further research.Spinning process forming stable quality indicators and forming quality Analysis are studied to realize the proper range of SDQ. On basis of that, establish a group of numerical experiments according to the control parameters to get the relationship between SDQ and forming quality, then build the model of SDQ-forming quality, thus realizing the proper range of SDQ and ASDQ.Proposed the multi-pass conventional SDQ distribution scheme based on gray relational multi-objective optimization analysis. Interactive multi-objective optimization experiments are designed using the proper rang of SDQ and ASDQ to achieve multi-pass conventional SDQ optimization. Meanwhile, the distribution multi-objective optimization scheme of multi-pass conventional spinning is tested by CNC spinning machine in the end.