Indexed by:期刊论文

Date of Publication:2019-05-01

Journal:INTERNATIONAL JOURNAL OF PRECISION ENGINEERING AND MANUFACTURING

Included Journals:SCIE

Volume:20

Issue:5

Page Number:815-825

ISSN No.:2234-7593

Key Words:Crack propagation; Critical depth; Initiation crack; Crack delayed growth; SPH simulation

Abstract:In order to study the mechanism of crack propagation, the varied cutting-depth scratch experiment is carried out and smoothed particle hydrodynamics (SPH) simulation method is used to assistant the investigation. The SPH simulation results reveal that crack will propagate in the direction where stress concentration exceeds the fracture toughness of K9 glass. The initial crack length in critical transition depth is calculated by combining the critical stress of fracture and the fracture toughness of K9 glass. Based on the effective plastic strain, the relation between scratching depth and crack depth is obtained. The recovery of crack tip is found and explained from the relationship between cutting depth and crack depth. Using the energy balance theory of Griffith, the variation of material internal energy is revealed. Comparing the scratching forces obtained from experiment and simulation, the validity of simulation results is verified. The phenomenon of crack delayed propagation is found in both experiment and simulation. The explanation of mechanism is given.