NUMERICAL FRACTURE TOUGHNESS TEST FOR IMPROVING WORKPIECE MODEL IN MACHINING SIMULATION

摘要

This paper presents a numerical fracture toughness test for evaluating the fracture toughness of a synthetic brittle material. Parallel-bonded particle model (PBPM) and distinct element method (DEM) are used to create a synthetic silicon nitride ceramic. The fracture toughness of the synthetic material is found by the newly developed numerical fracture toughness test. A parametric study shows that the fracture toughness of the synthetic material is mainly related to the normal bond strength between particles and the average particle radius. A correlation is obtained between the fracture toughness and the two parameters. The mathematical description is shown to be equivalent to that from linear elastic fracture mechanics (LEFM). The numerical fracture toughness test allows a better workpiece to be modeled for machining simulation.