The application of the essential work of fracture methodology to the plane strain fracture of ABS 3-point bend specimens

P. LUNA; C. BERNAL; A. CISILINO; P. FRONTINI; B. COTTERELL ; Y.-W. MAI

POLYMER

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2003 p. 1145 - 1150

0032-3861

The applicability of the EWF methodology to 3-point bend (SEB) specimens under conditions other than plane stress has been assessedexperimentally. Different fracture conditions, pure plane strain and plane strain/plane stress transition, were obtained by varying thespecimen thickness and testing temperature (20 and 80 8C). Post-mortem fracture surfaces appeared always completely stress-whitened,indicating ductile fracture. The load?line displacement plots are similar over a well-defined range of ligament lengths for which theapplication of the EWF methodology was in principle possible. Nevertheless, in experiments conducted at room temperature, crack growthwas observed to initiate before maximum load and complete ligament yielding. This behaviour was confirmed through plastic collapseanalyses. A critical ligament length was found, over which the total specific work of fracture was dominated by edge effects. Below thiscritical ligament length, EWF methodology was still applicable and it was possible to extrapolate reliable wIe values.