Numerical Study On The Dynamic Compression Of Porous Materials

Porous metal foam is a new kind of energy absorbing material,which has wide application prospects in many engineering fields due to its unique mechanical properties and excellent buffer energy absorbing characteristics.At present,although the dynamic mechanical behaviors of open-cell foam metals has been extensively studied by domestic and foreign scholars,there are relatively few studies on the influence of the randomness,pore size of porous materials and other factors on their mechanical properties.In addition,the experimental study on dynamic compressive mechanical properties of porous foam metal materials filled with liquid is still rare,and numerical simulation research is almost blank.Therefore,it is necessary and important to study the dynamic mechanical properties of the porous foam metal materials and their liquid-filled composite materials.In this paper,the dynamic compressive mechanical behaviors and energy absorption properties of open-cell foam copper and liquid-filled composite were studied by means of finite element numerical simulation combined with the experimental results of previous studies,and the energy absorption law and mechanism were also analyzed in detail.Firstly,the Kelvin tetradecahedral framework was selected as the typical cell of the porous copper foam,and the regular and random models of the same relative density and different porosity were established.The effects of pore size,randomness and impact velocity on the dynamic mechanical properties of porous materials were discussed by numerical simulation studies.On the basis of this,the Kelvin solid models of porous copper foam filled with liquid was established by means of fluid-solid coupling method and the dynamic compression behaviors and energy absorption characteristics of the porous metal materials which filled with liquid were analyzed.The effects of liquid-filler,viscosity,model randomness,pore size and impact velocity on the mechanical properties of liquid-filled porous metal materials were studied.Finally,based on the numerical results,the dynamic deformation process,energy dissipation and energy distribution of the porous metal materials with/without liquid filling were analyzed and discussed from the aspect of energy absorption.The effects of liquid viscous dissipation,liquid kinetic energy and solid-liquid interaction on the energy absorption of porous materials were obtained.The results of this paper have important theoretical significance for understanding the dynamic mechanical properties and energy absorption characteristics of fluid-filled porous materials,which provides important basis for the development and engineering application of the porous materials.