Study On Numerical Simulation And Networked Design Of Cold Roll Forming Process

Cold-formed steel is an economic cross-section of light thin-walled steel and it is widely used in all fields of national economy. Up to now, China has had more than 1,000 cold-formed steel production lines. Its production capacity reaches 15 million tons per year,. Therefore, it has important theoretical significance and practical value to study the cold bending forming process, reveal its forming law, develop practical design software to guide the actual production process.Cold roll forming is a widely used complex method for material deep-processing. It is a highly non-linear deformation process including geometric non-linearity, materials non-linearity and contact, and so on, and there are many factors which can affect the forming process. Therefore, the study of cold roll forming technology is a very complex subject. Up to now, neither domestic nor foreign scholars have yet offered a very complete and precise analysis procedure.This paper first summarizes the current state of cold-formed steel production, forming technology, forming theories, computer simulation of the forming process and CAD technologies in the world. Then by using the finite element method, finite strip method and analytical method, the cold roll forming mechanism has been systematically studied. Finally the networked design and integration of design, simulation and knowledge base for cold roll bending forming process are introduced.The cold roll forming is simulated by the commercial explicit finite element software ABAQUS. The simulation result is then followed by an implicit analysis to study the springback of the formed product. By comparison, good agreement has been achieved between the simulation result and the experiment result, so the computer model is proved to be correct and reliable.Therefore, these results have been used to validate other theories addressed in the paper..Based on the finite element method and the finite strip method of structural analysis, finite deformation theory has been introduced to elastic-plastic large deformation spline finite strip method. Non-uniform finite strip mesh discretization has been realized. The formulations are rigorously derived, and the results are in good agreement based on the analysis of channel steel and channel steel with outer edge (cold-formed beam)As the finite element method and finite strip method are computing intensive and there is a highly requirement for skilled engineers. To improve the simulation efficiency, a new analytical method based on the average longitudinal strain between stands has been presented. In the method, accumulative chord length parametric cubic spline curves were used to fit the longitudinal material passes to compute mean longitudinal strain between stands. The calculating process of the method needs almost no time, and the trend of its prediction found good agreement with finite element analysis..The above three methods, on the side of the calculation accuracy and reliability, the finite element method is superior to the finite strip method, finite strip method is superior to the analytic method; on the side of speed of calculation ,analytical method is superior to the finite strip method, while the finite strip method is better than the finite element method; on the side of technical requirements for engineers , analytical method and finite strip method is pretty much the same, but obviously better than the finite element method The multi-agent theory is introduced to the field of cold roll forming in the paper, the architecture of computer aided design platform of cold roll forming based on multi-agent is presented. The user's remote product design requirements and the distributed computing requirements are realized by using networked technology. The construction of knowledge base and bringing the actual production of design experience into the system help users to design suitable products more quickly. The above three kinds of analysis methods are applied in the multi-agent system, the simulation of cold-formed molding process can be more rapid and accurate .In short, the analytical method, finite element method and the non-uniform mesh discretization of finite strip method used in this paper are proved to be correct and effective, and they are able to simulate a variety of cold-formed steel forming process. In addition, application of multi-agent technology, cold roll forming design, simulation, knowledge data are integrated organic and distributed, a web-based distributed simulation system of cold roll forming computer-aided design is built, based on scientific analysis, the cost of tool designing is greatly reduced and the design risk is reduced, in addition , cold-formed product design has become more common, promoting the development of china's own intellectual property rights of commercial simulation software.