Reliability analysis of dynamic accuracy for the heavy-duty machine tool segmented beam

Abstract The dynamic reliability of heavy-duty CNC machine tool beam is directly related to the machining accuracy which is challenging to maintain because of the gantry machine structure. It is important to evaluate the reliability and accuracy of gantry machine components, especially the tool beam. This research investigated the dynamic accuracy of a segmented beam of gantry heavy machine tool by studying the surface morphology of the joint surface. The mechanical model of a single asperity is established based on the finite element method. The elastic and the plastic stage deformation boundary values are obtained, and the contact model of the full joint surface is established by using the Gaussian distribution characteristics. The finite element model of the sectional beam is developed by transforming the contact parameters of the joint surface. The accuracy of the model is verified by the field modal experiment. Additionally, the proposed model is used to analyze the impact of vibration on machining accuracy. The results revealed that the proposed model is highly reliable.