Study On The Thermal Conductivity And Local Compression Properties In Temperature Field Of Aluminum Foam Sandwich Panels

Aluminum foam sandwich(AFS)panels have the advantages of light weight,high stiffness,high damping properties and impact energy absorption rate,low thermal conductivity,good electromagnetic wave absorption and reflection ability.These excellent properties make it have been widely used in aerospace industry,train and automobile structures,household appliances,and civil structures.The AFS panel will be subjected to various forces in practical application.Therefore,the researches on the AFS panel have been paid more and more attention to its mechanical properties.In addition,the AFS panel also has a great application prospect in the extreme environmental conditions,such as the combustion chamber structure by gas turbines and steam turbines,nozzle structure of rockets and aircraft exhaust heat insulation devices.Therefore,it is very meaningful to explore the heat transfer properties and compression response at high temperature when studying the properties and developing applications of AFS panels.For the reasons above,the research on the properties of AFS panels is carried out in this paper,and the main work is as follows:Firstly,the two-dimensional random circle model of The AFS panel was established by using C++ and ANSYS software.The effective thermal conductivity of AFS panel was studied by simulation method,and the influence of porosity and cell size on the effective thermal conductivities was analyzed.The results show that the temperature distributions of AFS panel are uneven,and its effective thermal conductivity decreases with the increase of the porosity of the aluminum foam core.Meanwhile,it is found that the effective thermal conductivity of AFS panel also decreases with cell size increasing when the porosity is the same.On this basis,the simulation results are verified by the theoretical formula of the effective thermal conductivity of the AFS panel.Secondly,the quasi-static localized compression experiments of AFS panel under different temperature were completed.In addition,the effects of the experimental temperature,aluminum foam core porosity and face sheet thickness on the compression responses and energy absorptions of AFS panel were discussed.The results show that the deformation behaviors of AFS panel under different temperatures can be divided into three stages: elastic stage,plastic plateau stage and densification stage.In addition,due to the softening effect,the yield strength and energy absorption capacity of AFS panel decreases with increasing temperature.However,the densification strain of the specimens with the same porosity remains unchanged at different temperatures.At the same temperature,the yield strength,plateau stress and energy absorption capacity of the AFS panel correspondingly increases with the decrease of the porosity or increase of the face sheet thickness.Lastly,the local compression experiment of AFS panel under high temperature was simulated.By comparing the actual test results,the correctness of the simulation results and the feasibility of the simulation method are verified.In addition,the comprehensive effects of temperature,porosity and pore size on the local mechanical properties and energy absorption properties of AFS panel were studied by simulation.The results show that the maximum influence on the mechanical and energy absorption properties of AFS panel is the test temperature,and the influence of the pore size is the weakest.The results also show that the plateau stress and energy absorbed of the AFS panel decreases with the increase of temperature,porosity and pore size.