Predicting the crack initiation fracture toughness for a crack along the bimaterial interface

• Main Authors: Shah, Qasim Hussain, Azram, Mohammad, Iliyas, M. H.
• Format: Article
• Language: English
• Published: Asian Network for Scientific Information 2005
• Subjects: TJ227 Machine design and drawing
• Online Access: http://irep.iium.edu.my/5658/1/253-256.pdf; http://irep.iium.edu.my/5658/; http://scialert.net/abstract/?doi=jas.2005.253.256

Three Point Bend (3PB) bimaterial specimens of PMMA/PC were made by joining the two materials using friction welding. The specimens were tested and the crack initiation loads were recorded to evaluate the K using ASTM standard E 1820-01. Stress field in the crack tip vicinity was studied using finite element IC analysis of the specimen model. Normal and shear stresses were recorded for a series of nodes ahead of the crack tip at (2=0°). SIF values were calculated using these stress values and it was found that the stresses at a certain distance lying outside the process zone provide a SIF value matching to that of experimental fracture toughness of the specimen under study. Based upon the experimental evidence and finite element analysis, a simple step by step procedure is proposed to calculate the fracture toughness of bimaterials for a complex stress field.