The mechanisms of crack propagation from surface 3-D fracture under uniaxial compression

This paper studies the crack propagation of a three dimensional surface fracture using PMMA material with the changing cutting depth of the flaw V, flaw angle 'a' and flaw length 2c. When the cutting depth V of the flaw is equal or greater than 0.3 of the thickness of specimen, crack propagates much easier and further. For flaw angle agreater than or equal to60degrees and with the flaw length greater than or equal to50% width of specimen, the stress required for crack initiation is lower and the crack extends towards to the free boundary of the specimen in a shell shape form with spalling failure. This study provides the fundamental understanding on failure mechanics of crack propagation from 3-D surface flaws.