Dynamic characteristic analysis of a high speed hydraulic press

 

WU Qingping

(Shanxi Machinery and Electronics Industry Federation, Taiyuan 030001, China)

 

Abstract: Aiming at the dynamic characteristics of 80MN hydraulic press structure under very high working frequency, the finite element model for the dynamic analysis of 80MN hydraulic press structure was established, based on the principle of the ANSYS dynamics analysis and considering large computer resources needed for structure dynamic analysis. In this FEM model, the movable beam assembly was simplified, the leading truck was ignored, the joint between the movable beam assembly and the column was coupled in xdirection, the bottom of the movable beam was covered by object elements, the top surface of forging was covered by contact elements, the initial speed of the movable beam was set 15mm/s, and the initial acceleration of it was set 537mm/s2, the acceleration was loaded in step. The structure pretightening force was considered in the FEM model. The structural response under the dynamic load was successfully calculated. The stress distribution of the hydraulic machine under dynamic loads and deformation distribution was obtained. Simulation results show that the stress under dynamic loads is about twice of the static stress value and the maximum dynamic displacement is also about the maximum static displacement, and the weak stiffness location is also found. This provides a theory basis for more reasonable stiffness arrangement of the structure in design stage.

Key words: high speed forging hydraulic press; structure; dynamic characteristic analysis; finite element analysis(FEM); ANSYS