Research On The Forming Law Of Multi-process Draw-spinning

Modern spinning technology, an advanced plastic forming process widely used in aerospace and military industry, has become an important shaping method for flexible manufacturing of small-lot rotary thin shells. To ascertain the forming law of multi-process conventional spinning is a key problem urgently to be solved for the development of spinning technology. So, in this dissertation, the forming law of multi-process draw-spinning which is a typical method in multi-process conventional spinning, was investigated with computer numerical simulation combining with theoretical analysis. A brief introduction to the project and its main results are as follows:Based on analysis of the forming characteristics of draw-spinning, the four-node quadrilateral axial-symmetric element is used for discreting the blank, and some methods to treat loading and dynamic boundary conditions effectively have been proposed, then, a mechanical model corresponding to reality is established for elasto-plastic FEM simulation of multi-process draw-spinning. According to the principle of the energy method, an equation for critical compressive stress of bulking during draw-spinning process was deduced to provide a criterion for stable forming of multi-process draw-spinning.At the condition of roller motion trace being straight line, the forming process of multi-process draw-spinning is simulated with FEM, and under the condition of various pass, amount of feed, and processing parameters, the regularities of distribution of stress and strain is obtained. Which provide a reference for the choice and optimization of technological conditions of spinning.Based on the analysis of geometrical relationship between controlling parameters of different roller motion traces, a method of calculation ofThe project is supported by the Aeronautical Science Foundation of China(grant No OOH53075). And the Foundation of National Key Laboratory of Defense Science and Technology of China (grant No 98JS61.2.1 .HK03 14)controlling parameters is gained. The multi-process draw-spinning under different pass and roller motion traces is simulated. The results of distribution of stress and strain can be used as a guide for choosing roller motion trace of multi-process conventional spinning.