Contact thermal resistance modeling method considering elasticoplastic deformation of micro-bulge and thermal resistance of air medium

Abstract

The invention discloses a contact thermal resistance modeling method considering elasticoplastic deformation of a micro-bulge and thermal resistance of an air medium, wherein influence of the elasticoplastic deformation of the micro-bulge and the heat resistance of the air medium on the contact thermal resistance is considered. The method comprises: according to elastic deformation, elasticoplastic deformation and fully-plastic deformation of the micro-bulge, computing an actual contact area and contact load of a joint surface; then, respectively computing thermal constriction resistance and the heat resistance of the air medium, and computing total contact thermal resistance by virtue of combination of the thermal constriction resistance and the heat resistance of the air medium,; and finally, obtaining a relationship between the contact thermal resistance and the load by using a Matlab writing and computing program. The contact thermal resistance modeling method is characterized in that the influence of the elasticoplastic deformation of the micro-bulge and the heat resistance of the air medium is considered; the thermal constriction resistance, generated by elasticoplastic deformation, accounts for 15% of the total thermal constriction resistance; and when the load is relatively small, the influence of the heat resistance of the air medium is relatively large and cannot be ignored. The method provided by the invention can provide theoretical basis for computing the contact thermal resistance of boundary conditions for electro-spindle thermal state analysis.

Description

technical field [0001] The invention belongs to the field of research on the thermal characteristics of electric spindles, and relates to a contact thermal resistance modeling method considering the elastic-plastic deformation of asperities and the thermal resistance of the air medium. The method uses matlab to calculate and analyze the elastic-plastic deformation and the thermal resistance of the air medium. hindering effect. Background technique [0002] Motorized Spindle is one of the key components of CNC machine tools. Its characteristic is that the machine tool spindle and the spindle motor are combined into one, the machine tool spindle is directly driven by the built-in motor, and the main transmission chain of the machine tool is shortened to zero, thus realizing the zero transmission of the machine tool. The thermal characteristics of the electric spindle have a particularly significant impact on the machining accuracy of the machine tool. To establish a complete ...

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Problems solved by technology

At present, the modeling methods of thermal contact resistance mainly include the traditional Hertz contact model, the G-W model based on classical mechanics and statistics, the W-A contact model based on statistical parameters, and the M-B model based on the W-M function. The first three models have scale Dependence, affected by instrument resolution and sampling length, the latter model is comprehensive, deterministic, and scale-independent, but does not consider the elastic-plastic deformation of asperities, and does not consider the interstitial air medium thermal resistance

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