Study Of Thermal Deformation And Optimization Design Of Entire Roller Embedded Shapemeter Roll

Strip shape measurement is obvious technology bottleneck of closed-loop control of cold rolled strip shape. To research and develop domestic strip shape meter with proprietary intellectual property rights is now urgent and arduous task before us. Shape measuring roll is key detection part. The design precision and work performance of shape measuring roll is very crucial to cold rolled strip shape control.In the detection processs of shape measuring roll on eversible cold rolling, the tempeture of contact strip changes frequently and drasticly, and the thermal deformation value and change law of different parts of shape measuring roll is very different, therefore the interference fit condition will change and will easily influence the continuity of strip shape signal and the working stability of shape measuring roll. Thermal deformation problem is now the weakest link in study of shape measuring roll. This dissertation focuses on the newly developed entire roller embedded shape measuring roll, and makes systematical and thorough study on its thermal deformation problem in reversible cold rolling process, so as to improve the innovative design level of newly developed shape measuring roll.The calculation model of the heat transfer coefficient of shape measuring roll’s outside surface is established. The equivalent heat transfer coefficient of shape measuring roll’s outside surface and the heat transfer coefficient of strip contact surface in every rolling pass is calculated, so as to provide boundary conditions for temperature field calculation and finite element simulation. The temperature field model of shape measuring roll body is established by using heat conduction theory, and the temperature field model of interference fit surface is established by using one-dimensional composite medium theory. Then the temperature field of shape measuring roll in every rolling pass is calculated to support the analysis of the thermal deformation of shape measuring roll. On this basis, the temperature difference model of interference fit surface in rolling process is established, and the maximum temperature difference is calculated in the third rolling pass.The thermal deformation model of rool body and pressure sensor is estabilished by using thermoelasticity theory, and the thermal displacement of shape measuring roll is calculated. On this basis, the thermal displacement difference of interference fit surface is calculated and the interference fit value model is estabilished so as to analyze the contact condition of interference fit surface. The precompression model of pressure sensor is estabilished by using elastic mechanics and plate mechanics theory. The maximum thermal displacement difference of interference fit surface is calculated in the third rolling pass. So in this rolling pass, the precompression of sensors is likely to be zero and the strip pressure can not be detected, therefore the strip shape signal may become discontinuous.Based on the secondary development environment of finite element analysis software ANSYS, the coupled thermomechanical FEM simulation system is estabilished by using APDL parametric design language. The temperature field and thermal deformation of shape measuring roll body, temperature difference and thermal displacement difference of interference fit surface, and precompression of pressure sensor are all simulated and analyzed. Comparation between simulated and calculated results shows that the calculated models of temperature field, thermal deformation and sensor precompression are all correct and accurate.The optimal design model of shape measuring roll’s initial interference fit value is established. With the optimal object of reducing the difference of thermal displacement difference value and initial interference fit value, the optimum initial interference fit value is obtained so as to improve the contact condition of interference fit surface and working performance. Using the coupled thermomechanical FEM simulation system, the optimal design result can be verified.The study of thermal deformation of shape measuring roll is not only necessary for improving theory research level of strip shape measurement but also necessary for development strip shape meter with proprietary intellectual property rights. The research method and results in this dissertation can provide important theoretical basis and realization approach for research and development of domestic strip shape meter, and will be significant for innovative development of domestic strip shape measurement equipment and technology.