| Through forty-year's development of superhard material industry, China has uncontrovertibly become the major producer of synthetic diamond in the world. By 2005, the output of synthetic diamond had amounted to 70% of the total production. However, due to the lower products level and fewer categories, our country's research is still backward. At present, the domestic production is mainly based on the middle and low quality diamond manufactured by cubic apparatus, and the output reached 98% of the total amount. While high quality diamond produced by belt-type apparatus only accounts for 1～2%.There is a gap between the homemade belt-type apparatus and the advanced international standards. The short life and high production cost seriously impede the promotion of belt-type apparatus technology. Following the large scale trend, the life of cylinder has been the bottleneck. It is also a problem needed technical tackling. This research just keeps up with the international trend of manufacturing equipments of superhard material industry.Up to the present, the design and production technology of large-scale belt-type apparatus in our country has never been solved properly. In order to improve the strength and extend the life of cylinder, the stress state of belt-type apparatus should receive scientific analysis. In that way, we can optimize the stress of cylinder and accordingly make good use of the potential of die material. The domestic traditional design method of belt-type apparatus is always full of personal experience and lacks theoretical support. Currently, the domestic research on strip-wound die is almost a gap. Let alone the actual products applied to industry.Taking the cylinder as subject investigated, the thermo-mechanical coupled analysis of belt-type apparatus is put through and numerical simulation of winding tension is carried out with theoretical analysis and numerical simulation. Integrating numerical simulation with the optimization technology, the optimization of cylinder stress is realized with iSIGHT software platform. These make the present study significant to improving the design level and products quality of belt-type apparatus. Firstly, the basic theories of contact problems and nonlinear large deformation with finite element method are given, which offer the technique support to subsequent numerical analysis. By the aid of software MSC.MARC, the finite models of cylinder and prestressed rings are established. Compared to theoretical result of Lame equation, the contact algorithm in MARC applied to simulate shrink-fit is feasible and applicable.Secondly, the correlative programs suitable for loading boundary conditions are developed with FORTRAN. Then the distributions of temperature and stress fields of the cylinder in the active state are obtained. The thermal-mechanical analysis not only guarantees the relativity, but also gains the full data of the whole process. Since all those influence factors are taken into account at the same time, the numerical simulation reflects the receptacle status objectively. Based on the above results, the failure mechanism of belt-type apparatus is analyzed.Thirdly, the simplified model of strip-wound dies has been established to simulate the dynamic winding process. The stress distributions among steel-strip layers are obtained. The above research is of great importance to the design theories in strip-wound dies and the production practice.Fourthly, leading mathematic programming method into the of cylinder prestress, the integration between numerical simulation and optimization software is realized with MARC, iSIGHT and FORTRAN language. The modification of optimization design programs and the calling of batch processing files are automatically executed under the guidance of iSIGHT. And then the time of man-machine interactive process is shortened to a large degree. The optimized result is thus achieved.To sum up, our conclusion provides technical support to the design and optimization of belt-type apparatus and strip-wound dies. The research contains great significance in perfecting the relative design theories of dies and guiding industrial manufacturing.
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