Experiment Study And Numerical Simulation Of The Thermal Conductivity Of Filled Rubber Composite

With the rapid development of electrical engineering and automobile industry, rubber composites with high thermal conductivity have been a hot research topic recently. The most commonly used method to improve the thermal conductivity of composites is filling particles with high thermal conductivity. In this paper, experimental study and numerical simulation of thermal conductivity of filled rubber composites were studied.Experimental study:We set the heat probe experiment platform for measuring thermal conductivities of rubber composites. Thermal conductivities of A1N/EPDM and MWNTs/EPDM were measured from different directions. The results show that:A1N and MWNTs can significantly enhance the thermal conductivity of EPDM composites. Due to different orientations between A1N and MWNTs, the thermal conductivity differences of A1N samples with different directions is very small, and the MWNTs/EPDM composites’thermal conductivities of the different faces have significant differences, indicating obvious anisotropic properties. This method is instructive for the preparation of materials with high thermal conductivity in single direction.Numerical simulation:Using ANSYS finite element software, the effect of the particle shape, volume fraction, particle orientation, length-diameter ratio of column particle, thermal conductivity of particle, spatial distribution of particle on the thermal conductivity of rubber composites was studied.Under the low filling volume fraction, the cylinder particles filled composites has the highest thermal conductivity, the orientation affects the thermal conductivity of composites significantly, the bigger the aspect ratio of cylinder filler, the larger the increased range of the thermal conductivity. It is limited to improve the thermal performance of composites by increasing particles’ thermal conductivity. Critical ratio of filler thermal conductivity to matrix thermal conductivity for different filler particles will be reached with the increase of filler particle thermal conductivity. Under the critical ratio the thermal conductivity of composite increases with the thermal conductivity of filler, beyond the critical ratio there is no significant improvement.At the same volume fraction, the random distribution has higher thermal conductivity than the uniform distribution; when the volume fraction is between15%and35%, the effect of particles’spatial distribution on thermal conductivity is significant. The formation of thermal conductivity network chain is closely related to the particle spatial distribution. Particle-filled composites with high thermal conductivity could be made under proper spatial distributions.Finally, from the comparison between experiment date and numerical simulation result, the simulation results coincide well with the experiment dates, the trend is consistent. Thermal conductivity of composites can be predicted by the numerical simulation with finite element software. This can greatly reduce the number of experiments and the development costs. Numerical simulation with finite element software is instructive for the preparation of materials with high thermal conductivity.