Finite Element Analysis Of The Frame Of High Speed Forging Hydraulic Machine

The high speed forging hydraulic machine, which is most important equipment in pressure processing field, has become one of the equipments which cannot be shortage in industrial production.This paper has created three-dimensional finite element model of the frame of 12.5MN twin columns pull-down high speed forging hydraulic machine which is designed by Xi'an heavy-duty machinery research institute, analysed the stress and displacement distribution laws of the frame under static and dynamic load, and done the modal analysis of the frame on the base of studying theories and features of the high speed forging hydraulic machine and the structural finite element method, which provides reliable theoretical base and has important theoretical meaning and application value.The main research contents and results of this paper as follows:(1) The three-dimensional geometric model, mechanical model, static and transient dynamic model of the frame are created.(2) Stress and displacement distribution laws of the frame under three different working states are obtained through simulating the three typical working states of the frame, they are no offset load, offsetting load along X axis and offsetting load along Z axis. The main calculation results are:the four corners of the frame are strss concentrate areas, that is they are the dangerous cross-sections of the frame;The stress and displacement distribution trends are almost same under static and dynamic load, but under dynamic load, the largest stresses of the dangerous cross-sections are increased by about 40%;Offsetting load has a great effect on the bridge and upright column of hydraulic machine and makes the largest stress of the dangerous cross-section increased by about 20%.(3)The dynamic parameters of the frame such as previous ten naturalfrequencies and corresponding modes are obtained through modal analyzing the frame of high speed forging hydraulic machine. The simulating results indicate:The frame has not only fore and after, up-down and left-right bending vibration,but also twisting vibration. These vibrations will affect the strength and stiffness of the frame, wear guide sleeves of the frame, affect the precision of forge piece and decrease the service life of die and fluid cylinder, so during the course of designing, the effects of those vibrations should be prevented by increasing partial stiffness and damp;The whole stiffness and quantity of the frame are distributed with equalization,and there is no weak place and surplus location on the frame. The dynamic behaviors of the frame are well;The smallest frequency(23. 758Hz) of frame is larger than impact frequency(1. 33Hz) of frame greatly, so the resonance vibration wont take place on the frame;What' s more, it is larger than the frequency of 20Hz, so the design requirement of decreasing noise pollution is satisfied.(4) Analysis results i.ndicate:under static load, the largest stress of the dangerous cross-section of the 12. 5MN twin columns pull-down high speed forging hydraulic machine is between 60MPa and 90MPa,while under dynamic load, it is between 90MPa and ISOMPa, and they are also smaller than yield limit (270MPa)of the frame.Further, dynamic characteristics are very well, so the design of this machine is satisfying.The research contents and results of this paper, which contain stress distributon laws of the frame of high speed forging hydraulic machine under static load, dynamic load,no offset load and offset load and modalanalysis, provide reliable theoretical base for the design of new highspeed forging hydraulic machine.