J-R Curves of Rubber Modified Polystyrenes: The Use of Load Separation Parameter to determine Instantaneous Crack Lengths

P. M. FRONTINI; F. RUEDA; L.A. FASCE

Ottawa

Conferencia; 12th International Conference on Fracture (ICF 12); 2009

Natural Resources Canada - CANMET Materials Technology Laboratory (NRCan-CANMET) and the National Research Council of Canada (NRC)

Through this work J-R curves under quasi-static and impact loading conditions ofhigh impact polystyrene (HIPS) polymers differing in composition andmorphology were determined using the Load Separation Parameter to infer theinstantaneous crack growth length. The two advantages of this alternative methodover the usual multi-specimen technique are: i) it only requires one sharp and oneblunt-notched load–displacement record and ii) it does not necessarily requiresfinal crack length measurement, which is not trivial under impact loadings. Themethod was validated by the comparison of the estimated J-R curve with themulti-specimen technique for a commercial HIPS. The pseudo-initiationparameter, J0.2, was taken as the fracture toughness