A NEW ANALYTICAL MODEL FOR STRESS CONCENTRATION AROUND HARD SPHERICAL PARTICLES IN METAL MATRIX COMPOSITES

This analytical model predicts the stress concentration around an elastic, spherical particle in an elastic-plastic metal matrix using strain gradient plasticity theory and a finite unit cell. The model reduces to the special case with a spherical particle in an infinite matrix. It simplifies to models based on classical elasticity and plasticity, also. The solution explains the particle size effect and accounts for composites with dilute and non-dilute particle distributions. Numerical results show that the stress concentration factor is small when the particle size is tens of microns. The stress concentration factor approaches a constant when the particle size is greater than 200 microns