Study on Cold Stretching Control Strategy and System

Based on analysis of material test and numerical simulation of cold-stretched vessel, the proper rate of pressure rise and control strategy is studied. And the cold stretching control system is developed. The main work and achievement of this thesis are as follows:(1) The effect of strain rate on mechanical properties of06Cr19Ni10, which is one kind of home-made austenitic stainless steel, is studied. And the proper circumference strain rate of cold-stretched vessel is proposed.(2) A numerical simulation method is raised by pressure-strain curve of the cold-stretched vessel, as a result, the strain rate is skillfully transferred into the pressurization rate. A post-processing software is programmed to process the result of numerical simulation and establish the pressure-volume curve. A four-phase control strategy is raised by the research above and the PID control section is performed by simulation experiment.(3)The software and hardware are designed,. the control system is developed for cold-stretched vessel, and experiments are performed by using system above. The result turned satisfying with the stable data, the accurate control and the steady pressurization rate.