Last modified: 2018-07-22
Abstract
The important physical and mechanical properties exhibited by porous materials have led to a vast range of industrial and engineering applications. Used as light-weight materials, catalyst carriers, electrodes, vibration and acoustic energy damping materials, impact energy absorption materials, they have aroused the interest of many researchers particularly over the last three decades. Mechanical and physical properties for the structural materials such as elasticity, plasticity and thermal conductivity have been largely investigated with the pore morphology as the main parameter of the studies, see [1] for the thermal conductivity and [2] for the plastic property.
In this study, a numerical homogenization technique and morphological analysis based on the finite element method are used to compute mechanical properties of porous materials. This is achieved by considering two–dimensional matrix containing random distribution of identical non–overlapping circular or elliptical voids. Several microstructure configurations are considered by varying the voids morphology and the porosity of the matrix. The notion of the representative volume element (RVE) is used for numerical simulations in order to estimate the morphology effects of the voids on the effective elasticity modulus of the called Lotus–Type Porous Metals [3].
A confrontation of the obtained numerical results of the representative microstructures for different morphologies of voids and different properties with an analytical model and experimental data is performed. Finally, a formula improving the Boccaccini model is proposed to estimate effective elasticity modulus of porous metals taking into account the voids morphology [4].
Keywords: Numerical homogenization, lotus type porous metals, effective elasticity modulus, representative volume element.
References :
[1] W. Kaddouri and al. effective thermal conductivity of heterogeneous materials, J Mech Mater. 2016, 92:28-41.
[2] M. Masmoudi and al. Modeling of the effect of the void shape on effective ultimate tensile strength of porous materials: numerical homogenization versus experimental results. International Journal of Mechanical Sciences 2017,130:497-507.
[3] T. kanit and al. Determination of the size of the representative volume element for random composites: statistical and numerical approach. Int J Solids struct 2003;40(13):3647-79.
[4] Boccaini and al. Determination of stress concentration factor in porous materials. J Mater Sci Lett 1996; 15(6):534-59.