Method for Predicting Thermal Characteristics of Machine Tools Based on Experimental Modal Analysis

Abstract

The article describes the method for predicting the thermal characteristics of CNC machine tools working at finishing cutting modes with variable cutting speeds. This allows not taking into account the generation of heat in the main sources due to additional loads from cutting without introducing significant distortions in the adequacy of the mathematical model in the construction of thermal characteristics. The thermodeformation model of the machine is represented by a system of thermal characteristics that describe both its thermal and deformation behavior. A feature of the proposed method is the use of the entire set of approximated experimental thermal characteristics for the complex mode of operation of the machine under consideration. Each approximated thermal characteristic used in the model is formed from the results of the full-scale experiment with a continuous operation of the machine tool at a fixed spindle rotational speed. The mathematical description of each thermal characteristic is based on the experimental modal analysis, in which the modal parameters of the thermodeformation model are determined from the experiment. A feature of the approximated thermal characteristics is their multimodal representation. The results of full-scale and computational experiments are presented in the article.