NC Tube-bending Forming Quality Analysis And Numerical Simulation System Integration

With the development of industry production and technology , the processing of tube-bending has been more and more important in many industrial sectors such as structural hardware, engineering machine, power machine, boiler, light industry and aeronautics and space industry, but at the same time higher and more advanced tube-bending technology is required. The prediction and control of tube shaping defection and improvement of tube bending technology have become tough problems to be solved.This paper is based on the bending process of power station boiler tube, and I studied the relevant issues of NC tube bending technology in depth. I analyzed present researches of the shaping quality of NC tube bending from home and abroad, and based on these analyses, I analyzed the working condition of the tube when being bended and established the theoretical mechanics model of NC tube bending. I also introduced the process of tube cold bending, defined the calculation of the spring back angle, introduced the plastic forming theory, analyzed the yield criterion of plastic forming process, fluxion isotropic hardening, plastic constitution relationship and derived the plastic solve process. By analyzing the working condition of the tube being bended, I got the axial stress distribution on the section of the curved tube, and then derived the calculating formula of the spring back angle. The NC tube bending FEA model was built in large nonlinear finite element software--Marc by setting the material construction relationship of FEA method, handling the boundary condition, setting the solving algorithm and handling other critical technology. The factors that can influence the tube bending quality and the spring back quantity can be analyzed by arithmetic analysis of the model. And the practical applications shows that we can improve the shaping quality and the accuracy of the shaping angle by improve those factors. Based on studies of relative technology, the integrated CAD/CAPP/CAE bending system based on mutual commercial software–VC++6.0 has been developed, which has successfully loaded Pro/E re-develop module, FEA module based on ANSYS, CAPP module and result analysis module based on Marc, I also developed a simple human-computer interface. Data transmission without obstacles is realized by this integrated system and the design cycle was reduced.