ORAL REFERENCE: ICF100650OR ON THE APPLICABILITY OF THE ESSENTIAL WORK OF FRACTURE METHOD TO THICK ABS SE(B)-SPECIMENS P. Luna 1 , P. Frontini 1 *, A. Cisilino 1 , C. Bernal 1 , B.Cotterell 2 and Y-W Mai 2 1 INTEMA, (UNMdP-CONICET), J. B. Justo 4302, 7600, Mar del Plata, Argentina. 2 Mechanical and Mechatronic Engineering Department, The University of Sydney, NSW 2006, Australia. ABSTRACT This paper deals with the application of the EWF methodology to thick ABS SEN(B)-specimens in order to study its applicability to conditions other than plane stress. Different loading regimes were induced by varying the testing temperature. Post-mortem fracture surface appears to be completely stress whitened, indicating ductile fracture. Load-line displacement plots display geometric similarity over a well-defined range of ligament lengths for which the application of the EWF methodology was in principle possible. At the same time crack growth was observed to initiate before maximum load and the complete ligament yielding. Over a critical ligament length gross yielding occurred and the total specific work of fracture was found independent of ligament length. Below this critical ligament length, EWF methodology seemed to be still applicable and it was possible to extrapolate reliable w e values. Besides, the EWF was simulated by elastic-plastic FEM analysis. Numerical results were consistent with experimental findings. KEYWORDS: essential work of fracture (EWF) applicability; ABS; plane stress- plane strain regime; FEM modeling. INTRODUCTION The essential work of fracture (EWF) has developed as an efficient methodology to characterize the fracture toughness of ductile polymers films under the plane stress condition[1-4]. At the same time the simplicity of this methodology makes very attractive to extend its applicability to other loading conditions, such us the plane-stress plane-strain transition and pure plane-strain regimes [5-11]. In this sense the present work deals with the application of the EWF methodology to thick ABS SEN(B)-specimens, for which different loading conditions were induced by varying the testing temperature. Experimental results are complemented with numerical FEM simulations. THE EWF METHODOLOGY The EWF method is based on the assumption that the total work of fracture, w f , consists of two work components: one referred to as the essential work of fracture, w e , which is related to the failure mechanisms that occurs in an inner fracture process zone, and the other referred as the non-essential total work of fracture, w p , which stands for the work dissipated in the outer plastic deformation zone and is geometry- dependent. To this extent application of the EWF must fulfil the following conditions [4]: (1) the ligament should yield prior to fracture initiation; (2) w e should be proportional to the ligament length, l; and (3) w p