Effect of the consolidation degree on the fracture and failure behaviour of self-reinforced polypropylene composites as assessed by acoustic emission

IZER ANDRAS; ARIEL STOCCHI; BÁRÁNY TAMÁS; VALERIA PETTARIN; CELINA BERNAL; TIBOR CZIGANY

Budapest

Conferencia; 14TH EUROPEAN CONFERENCE ON COMPOSITE MATERIALS; 2010

In this work, the failure behaviour of self-reinforced polypropylene composites (SRPPC) was studied. As reinforcement a fabric, woven from highly stretched split PP yarns, was used whereas as matrix materials α and β crystal forms of isotactic PP homopolymer and random PP copolymer (with ethylene) were selected. Composite sheets were produced by a film-stacking method and compression moulded for constant holding time and at constant pressure but at different processing temperatures to obtain SRPPC sheets with different consolidation degree. The failure behaviour of tensile specimens was assessed by the acoustic emission (AE) technique and the typical failure behaviour was deduced for the different consolidated composites. Both the number of AE events and the shape of the cumulative AE events versus deformation curve depend on the adhesion between phases. Correlations between the dominant failure mechanisms and AE events amplitude for model specimens were established. They can be used to monitor the damage growth process in SRPPCs.