Structure Optimization Of Frame Of 12500KN/3500KN Combined Hydraulic Press

Special cylindrical workpiece is the key part of main weapon of our country. Theoriginal manufacturing facilities are backwards, the productivity of which is very low.The production can not meet the demand of National Defense Industry. Therefore, someenterprise developed the new 12500kN/3500kN combined hydraulic press in order toimprove the technology of special cylindrical workpiece.The combined hydraulic press combines two frames by frame connectingtechnology. Now the new hydraulic press can accomplish all the procedures which werecompleted by three hydraulic presses. In order to check whether the design is reasonableand find the defect of the frame, it is significant to analyze the frame by finite elementmethod. Then the improved solution could be proposed to improve the design.By the finite element analysis software MSC.Marc, the paper analyzed the staticstrength and stiffness of the frame under the cupping and drawing condition, gaining thestress distribution of frame, distortion of the pillars, the upper and lower worktable,extracting the distortion curve of pillars, finding the location of the maximumdisplacement on the inside surface of pillar. The modal characteristics were also analyzed,gaining the first ten natural frequencies and the corresponding vibration modes,providing evidence for optimization.Based on the above results, adopting sequential quadratic programming, theoptimization of the frame was conducted in the conditions of certain strength, stiffnessand modal characteristics, gaining a series of optimal design parameters, making theweight of the frame minimum, saving the materials and reducing the manufacturing cost.The frame for test was designed in the ratio of 1 to 8. The cupping condition wassimulated by hydraulic cylinder, the drawing condition was simulated by jack. Themaximum displacement of guides of the frame and the axial stress were measured. Theresults showed that the stiffness of the optimized frame could meet the demand meaningthe series of parameters gained by optimization were reliable.