Discrete element modelling of silicon nitride ceramics: Crack formation and propagation in indentation test and four point bending test
Advanced ceramic materials have been extensively used in aerospace, automobile and other industries. However, the reliability of the advanced ceramics is the major concern because of the brittle nature of the materials. This work aims to model silicon nitride ceramics using Discrete Element Method (DEM) and simulating the crack formation and propagation. DEM software package PFC 2D is used to simulate indentation test and four point bending test on silicon nitride ceramics and the behaviour of crack formation and propagation is identified. The numerical representation of ceramic materials is done by generating a densely packed particle system using the specimen genesis procedure and then applying the suitable microparameters to the particle system. Indentation test has been performed on the sample with different loading forces and the width and depth of cracks generated have been studied. Four point bending test has been simulated and the fracture origins has been identified. Simulation of four point bending test is performed on sample having no defects, sample having manufacturing-induced defects like cracks, and sample having material-inherent flaws like voids. For the above cases the initiation and propagation of defects is simulated and the mean contact force on the loading ball is also obtained and plotted. The simulation prediction results are well in accordance with the experimental nondestructive testing results.
Senapati, Rajeev, "Discrete element modelling of silicon nitride ceramics: Crack formation and propagation in indentation test and four point bending test" (2009). ETD Collection for University of Texas, El Paso. AAI1473893.