INFLUENCE OF SPECIMEN GEOMETRY AND UD PLY LAYUP ON THERMOPLASTIC WELDED DOUBLE-NOTCHED TENSION TEST SPECIMEN BY USE OF MECHANICAL AND VIRTUAL TESTING

Thermoplastic composites can play a key role in developing future forms of transportation due to their high mechanical performance as well as their wide range of automatable joining and manufacturing methods. Thermoplastic welding techniques like induction and resistance welding provide flexible joining methods for many applications such as skin-stringer joints in an aircraft fuselage. With various welding processes existing, finding a suitable testing method to compare these processes would be beneficial. This paper shows the sensitivity of an ASTM D3165 based testing method (designated as double-notched tension test in this paper) especially to notch depth, as well as the three different laminate layups. It highlights the challenges to sample preparation and result interpretation, as well as the suitability of the testing method for the comparison of different welding techniques. Virtual testing is performed with a continuum damage finite element model, which is capable of mapping inter and intra-laminar failure, as well as failure of the welding zone itself to gain insight into the mechanical behavior of the tested sample.