Experimental verification of the Fictitious Material Concept for tensile fracture in short glass fibre reinforced polyamide 6 notched specimens with variable moisture

In the present research, the fracture prediction of U-notched single edge notched bend (SENB) specimens made of the short glass fibre reinforced polyamide 6 (SGFR-PA6) with variable moisture is investigated experimentally and theoretically. In the experimental program, numerous rectangular specimens weakened by edge U-shaped notches of different tip radii are tested for fracture under pure mode I loading, and the load-carrying capacity (LCC) of the specimens is experimentally measured. In the theoretical program, in order to avoid time-consuming and complex elastic-plastic failure analysis, and due to the significant strain-hardening and the substantial strain-to-failure of the composite material tested, the prediction of the experimentally obtained LCCs is approached in order to test its validity using the Fictitious Material Concept (FMC), proposed most recently by the first author, in combination with the well-known Theory of Critical Distances (TCD). According to the new proposed failure model, since the fictitious linear-elastic material is used, TCD can be applied by means of its basic formulation without considering any previous calibration of the corresponding critical distance. It is revealed that the FMC-TCD combined criterion can predict the experimental results well.