Volume 8, Issue 5 (September 1980)
Measuring JIc, and the Resistance to Crack Growth After Initiation
A ductile fracture toughness (JIc) test that uses fracture specimens with finite differences in crack area is reviewed. Experimental results are given for Ti-6Al-4V, A471 Ni-Cr-Mo-V rotor steel, and 4140 high strength steel. Resistance to further crack propagation after initiation is discussed in terms of the tearing modulus, which is equal to dJ/dA, A being the crack area. A useful expression for the tearing modulus is given.