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CNC milling machine is used for large -site field service petrochemical plant processing equipment , in order to adapt to the scene of the processing environment, requiring on-site milling machine to meet the performance, accuracy and other conditions, its mass and volume as small as possible . In practice, since the force due to deformation white beam -excited vibration , resulting in the workpiece surface corrugated marks, seriously affecting the machining accuracy and surface quality. With the help of COSMOSWorks finite element software, establish on-site milling finite element model , its main moving parts for static and dynamic analysis, based on the relative deformation of the beam vibration mode shape and amplitude analysis of the main factors affecting the machining accuracy for structural optimization theoretical basis for improving the performance of on-site milling work has a very important significance. Based on the theoretical analysis of the on-site milling beam structure in the process of its subject , static and dynamic stiffness of the machining accuracy, using the finite element method , using COSMOSWorks software, crosspiece static and dynamic stiffness of the simulation and verification . These include : 1. Pair of beams in the process of the mechanical analysis , and based on the theory of deformation of the beam elements , and according to the milling force calculation formula to calculate the beam in the process of force in all directions . (2) Through the milling and mechanical properties of structural modeling analysis , access to the crossbar in the middle position of the three directions of maximum deformation and beamed five order natural vibration modes seen by comparing the maximum Z-direction deformation , which was the stiffness in the Z direction is weak , affect the machining accuracy of the cause, and the first-order natural frequency is low , the vibration in the Z- direction is the performance of its low rigidity . 3 through the transom beam analysis to optimize the design , based on finite element analysis and modal changes proposed on the basis of eight pairs of beams improvement program , by the finite element analysis of comparison, the meter can be shaped ribs effectively improve the overall stiffness of the beam , reducing the beam deformation in the Z direction , to improve the precision of the milling site .
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