The J-integral as a fracture criterion for polycarbonate thermoplastic

Abstract

Fracture behaviour of a polycarbonate thermoplastic has been investigated. Fracture tests were conducted on single edge notched specimens and the J-integral evaluated using energy rate interpretation. Its value has been found to be independent of crack length when crack length to specimen width (a/w) is larger than 0.34. For smaller cracks general material damage away from the crack tip is also found to influence the energy absorbed. An extrapolation method has been used to separate the crack tip energy from the energy absorbed due to general material damage. The J-integral thus obtained is independent of crack length and specimen length and its critical value is the same as obtained for a/w > 0.34 without extrapolation. The critical stress intensity factor was also evaluated using the R-curve approach. It has been found that the J-integral agrees well with the criticial stress intensity factor obtained using the R-curve approach.

Ductile fracture characterization of polycarbonate by the R-curve method

“…Similar conclusions were obtained with J(.. This last remark is not in agreement with the recent results reported by Singh and Parihar [4] who found, by using SENT specimens, that fracture of a 4 mm thick polycarbonate sheet was obtained for a critical value of the J-integral (J~.). In our opinion, their results apply only to tension specimens of a given width and they cannot be generalized to other specimen widths and geometries.…”

Fracture toughness evaluation for short glass fibre reinforced composites

“…The Jc value thus evaluated was found to be approximately independent of crack length when the crack length to single-edge-notched specimen width ratio (a/w) was larger than 0.35. Singh and Parikar [15] employed the same approach to study the fracture behaviour of a polycarbonate thermoplastic and a similar result to that reported in Reference 14 was obtained.…”

Work of fracture of polystyrene/high density polyethylene blends compatibilized by triblock copolymer

“…10,11 On the contrary, for polymers having a low Y , such as polypropylene (PP) and polyethylene (PE), the size limitation presents some practical difficulties. 12 Another approach used to characterize the fracture toughness of ductile materials is the essential work concept, which was originally proposed by Broberg.…”