Keywords : mode shape
Engineering and Technology Journal,
2016, Volume 34, Issue 8, Pages 1499-1513
A closed loop simulation is used for minimizing of undemanding vibration caused in the dish system. The finite element method is used to model the closed loop control via ANSYS- APDL. In this paper the Bezier function for surface modeling to get the best modeling points for dish is used. A designed surface is represented by sufficient control points, using these control points, the surface has been represented depending on Bezier technique to generate reliable and near-optimal dish surface. The required equations are generated to apply the surfaces and curves efficiently using MATLAP program, then exported to ANSYS to perform closed loop vibration analysis. It can be concluded that the closed loop control system with gain (Kp=4, Ki=1, Kd=0.1) suppression the vibration of the dish with 98% with different thickness and materials of dish. Also the natural frequencies and the mode shapes of the dish is evaluated. Three materials (pure copper, pure aluminum and steel) each with different thickness is taken for the dish (0.8, 0.9, 1, 1.1 and 1.2) mm and for each thickness the responses and the natural frequencies are determined for six modes. The effect of the thickness’s variation on natural frequencies for each material was studied. It can be observed that natural frequency is direct proportional with the thickness of the dish.