Volume 1, Issue 3 (May 1973)
Work of Fracture and Fracture Toughness of Graphite
Compact tension tests and notched bend tests, according to Tattersall and Tappin, were performed on nuclear graphite in different orientations relative to the extrusion direction. The extension of slow propagating cracks was measured. The critical crack extension compares with the dimensions of defects in the graphite such as shrinkage cracks, pores and crack-like pores which are caused by the extrusion process. Taking these cracks into account results in comparable fracture toughness values regardless whether they are determined by a load criterion or from the work of fracture.