Computational micromechanics of composites: The effect of particle spatial distribution

Abstract The effect of the reinforcement spatial distribution on the tensile deformation was investigated in a sphere-reinforced ductile-matrix composite through the finite element simulation of a representative volume element of the material. Composites with four different random and isotropic particle spatial distributions were considered: a homogeneous one and three heterogeneous ones, where the particles were clustered in spherical regions with increasing local reinforcement volume fractions. The inhomogeneities in the particle spatial distribution had a negligible influence on the effective composite properties in the elastic and plastic regimes. The average stresses borne by the particles were, however, higher in the clustered microstructures and marked stress concentrations were found between particles very close to each other along the loading direction. This affected the damage: the probability of fracture of the spherical reinforcements in the clustered materials was 3–6 times higher than in the homogeneous one, and decohesion at the particle/matrix interface (which was simulated by interface elements around the particle surfaces) occurred earlier and grew faster in the inhomogeneous composites, leading to a significant reduction in the hardening rate and ductility. These simulations showed that damage (either by particle or interface decohesion) was preferentially nucleated within the clusters between particles very close to each other and oriented along the loading axis within a conic angle of ±45°, in excellent agreement with the experimental observations reported in the literature.

[1]  J. Llorca,et al.  A self-consistent approach to the elasto-plastic behaviour of two-phase materials including damage , 2000 .

[2]  Anthony G. Evans,et al.  Interface adhesion: effects of plasticity and segregation , 1999 .

[3]  Javier Segurado,et al.  A numerical approximation to the elastic properties of sphere-reinforced composites , 2002 .

[4]  J. Segurado,et al.  A computational micromechanics study of the effect of interface decohesion on the mechanical behavior of composites , 2005 .

[5]  John J. Lewandowski,et al.  Effects of matrix microstructure and particle distribution on fracture of an aluminum metal matrix composite , 1989 .

[6]  Y. Benveniste,et al.  A new approach to the application of Mori-Tanaka's theory in composite materials , 1987 .

[7]  S. Torquato.  Random Heterogeneous Materials , 2002 .

[8]  Javier Segurado,et al.  Three-dimensional multiparticle cell simulations of deformation and damage in sphere-reinforced composites , 2004 .

[9]  Javier Segurado,et al.  A numerical investigation of the effect of particle clustering on the mechanical properties of composites , 2003 .

[10]  Javier Segurado,et al.  On the accuracy of mean-field approaches to simulate the plastic deformation of composites , 2002 .

[11]  S. Nemat-Nasser,et al.  Micromechanics: Overall Properties of Heterogeneous Materials , 1993 .

[12]  K. Tanaka,et al.  Average stress in matrix and average elastic energy of materials with misfitting inclusions , 1973 .

[13]  M. Elices,et al.  Particulate fracture during deformation , 1993, Metallurgical and Materials Transactions A.

[14]  J. Llorca.  An analysis of the influence of reinforcement fracture on the strength of discontinuously-reinforced metal-matrix composites , 1995 .

[15]  Helmut J. Böhm,et al.  Comparisons between three-dimensional and two-dimensional multi-particle unit cell models for particle reinforced metal matrix composites , 2001 .

[16]  Y. Mahajan,et al.  Structure–property correlation in discontinuously reinforced aluminium matrix composites as a function of relative particle size ratio , 2002 .

[17]  W. Drugan,et al.  A micromechanics-based nonlocal constitutive equation and estimates of representative volume element size for elastic composites , 1996 .

[18]  T. Clyne,et al.  Cavity formation during tensile straining of particulate and short fibre metal matrix composites , 1993 .

[19]  Rajiv S. Mishra,et al.  Friction Stir Welding and Processing , 2007 .

[20]  P. Withers,et al.  Weibull modelling of particle cracking in metal matrix composites , 1995 .

[21]  Javier Segurado,et al.  A new three-dimensional interface finite element to simulate fracture in composites , 2004 .

[22]  Salvatore Torquato,et al.  Effective stiffness tensor of composite media : II. Applications to isotropic dispersions , 1998 .

[23]  J. Llorca,et al.  Fracture toughness and fracture mechanisms of Al-Al2O3 composites at cryogenic and elevated temperatures , 1996 .

[24]  Javier Segurado,et al.  Numerical simulation of elasto-plastic deformation of composites: evolution of stress microfields and implications for homogenization models , 2004 .

[25]  Rintoul,et al.  Reconstruction of the Structure of Dispersions , 1997, Journal of colloid and interface science.

[26]  R. Christensen,et al.  Solutions for effective shear properties in three phase sphere and cylinder models , 1979 .

[27]  J. Llorca,et al.  Microstructural factors controlling the strength and ductility of particle-reinforced metal-matrix composites , 1998 .

[28]  Laurent Babout,et al.  Damage initiation in model metallic materials: X-ray tomography and modelling , 2004 .

[29]  A. A. Gusev.  Representative volume element size for elastic composites: A numerical study , 1997 .

[30]  H. Böhm,et al.  Multi-Inclusion Unit Cell Studies of Reinforcement Stresses and Particle Failure in Discontinuously Reinforced Ductile Matrix Composites , 2004 .

[31]  J. Michel,et al.  Effective properties of composite materials with periodic microstructure : a computational approach , 1999 .