Investigation of Ultrasonically Welded Thermoplastic Composite Joints Using Netlike Energy Directors

Abstract This paper proposes a netlike energy director (ED) made of carbon fiber-reinforced thermoplastic (CFRP) composites for ultrasonic welding. To explore the benefits using EDs, joint qualities with flat EDs and without are included references. The influence ED geometry on weld attributes quality investigated in terms cross-sectional microstructure, fracture morphology, maximum shear load. It is found that both welding process can be accelerated compared one caused by concentration into expected region avoidance edges introduced surface curvature. Meanwhile, loads joints higher than those because decrease contact area consequent cyclic strain, resulting more melted materials during process. However, increasing thickness, porosities generated layer leading to reduced bonded From morphology analysis, it introduce fibers layer, modes include fiber-matrix debonding fiber pull-out addition polymer fracture, confirming feasibility improving introducing CFRP EDs.