三维分形接触热导的建模与多参数影响分析

Modeling of 3-D fractal thermal contact conductance and multi-parameter effect analyses

在传统M-B接触模型的基础上,利用三维分形理论,推导三维分形结合面的接触模型,并建立了三维分形接触热导模型。通过仿真分析揭示了法向载荷、分形维数、分形尺度参数、材料特性参数及各参数的耦合对接触热导的影响。仿真结果表明:接触热导与法向载荷呈正相关,当2.1≤D≤2.4时,两者存在非线性关系,当2.5≤D≤2.9时,两者趋于线性关系;当2.0<D≤2.95时,接触热导随分形维数的增大而增大,当2.95<D<3.0时,接触热导随分形维数的增大而减小;接触热导与分形尺度参数呈负相关,与材料特性参数呈正相关;并得出上述参数两两耦合对接触热导的影响。

On the basis of the traditional M-B contact model,adopting the3-D fractal theory,the contact model of a3-D fractal interface was derived and the3-D fractal thermal contact conductance model was established.The effects of normal load,fractal dimension,fractal scale parameters,material characteristic parameters and couplings between any two of all these parameters on thermal contact conductance were revealed with simulation analyses.The results showed that the thermal contact conductance is positively correlated to normal load;when2.1≤D≤2.4,there is a nonlinear relationship between them;when2.5≤D≤2.9,they tend to have a linear relationship;when2.0<D≤2.95,thermal contact conductance increases with increase in fractal dimension;when2.95<D<3.0,it decreases with increase in fractal dimension;thermal contact conductance is negatively correlated to fractal scale parameters,and it is positively correlated to material characteristic parameters;effects of couplings between any two of all these parameters on thermal contact conductance are also gained.