Three-dimensional fractal prediction method of thermal contact resistance of bonding surface considering asperity substrate deformation

Abstract

The invention provides a three-dimensional fractal prediction method for thermal contact resistance of a bonding surface considering the deformation of an asperity substrate, and relates to the technical field of mechanical bonding surfaces. In this method, the two-dimensional fractal function is replaced by the three-dimensional fractal function of the surface topography that is closer to the actual situation, and the contact deformation of the asperity is represented by the amplitude difference between the peak and trough of the three-dimensional function; then the asperity is calculated Elastic critical deformation and critical contact area in the elastic deformation stage of the body and the deformation of the asperity matrix; finally, the relationship between the total normal load of the joint surface and the contact area and the total normal load of the joint surface and the total contact area of ​​the joint surface were established. relationship between thermal resistance. The three-dimensional fractal prediction method of the contact thermal resistance of the joint surface considering the deformation of the asperity substrate provided by the present invention is more accurate and closer to the actual situation, and can provide a theory for the contact thermal resistance of the joint surface in the mechanical thermal state analysis in accordance with.

Description

technical field [0001] The invention relates to the technical field of mechanical bonding surfaces, in particular to a three-dimensional fractal prediction method for thermal contact resistance of bonding surfaces considering the deformation of asperity matrix. Background technique [0002] In the manufacture and assembly of machine tools or various mechanical equipment, the mechanical structure is generally not a continuous whole, including a large number of parts, and the contact surface between the assembled parts is called the joint surface. During the working process of mechanical equipment, each component, each component and the whole mechanical equipment will be under the action of various heat sources, so that a certain temperature field will be formed inside the component, so that thermal deformation will inevitably occur on the mechanical joint surface, thus Affect the overall performance of the mechanical structure. Therefore, theoretically studying the contact b...

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Problems solved by technology

[0004] Although the contact thermal resistance model of the mechanical joint surface has been continuously developed and perfected by the unremitting efforts of domestic and foreign scholars, it is still relatively difficult to use the existing contact thermal resistance model to calculate the contact thermal resistance between the joint surfaces under heavy load conditions. big error

The main reason is that the existing contact thermal resistance calculation model does not consider the influence of the deformation of the asperity matrix. can not be ignored; at the same time, the existing calculation model of the contact thermal resistance of the mechanical interface ignores the characteristics of the fractal distribution of the three-dimensional surface of the asperity

Therefore, under heavy load conditions, the contact thermal resistance of the bonding surface cannot be accurately calculated using existing theoretical methods

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