ULTRASONIC WELDING OF ADVANCED （先进的超声波焊接）.pdf

ULTRASONIC WELDING OF ADVANCED THERMOPLASTIC COMPOSITES: AN INVESTIGATION ON ENERGY DIRECTING SURFACES I. Fernandez, D. Stavrov, H.E.N. Bersee Design and Production of Composites Structures Delft University of Technology Kluyverweg 1, 2629 HS Delft I.Fernandez@TUDelft.nl SUMMARY Research on different energy directing surfaces for ultrasonic welding of advanced thermoplastic composites was performed. Special attention was paid to the influence of the orientation of the energy directors with respect to the load direction and to multiple energy directors’ configurations. Keywords: Thermoplastic composites, processing techniques, ultrasonic welding, energy directors, mechanical testing INTRODUCTION Fusion bonding, also known as welding, is considered to be a technique ideally suited for joining continuous fibre reinforced thermoplastic c omposites (CFTPCs). It takes advantage of the main characteristic of thermoplastic resins, which is the possibility of being melted and cooled while retaining their properties. Fusion bonding eliminates the well known drawbacks of the traditional joining techniques, like stress concentration and intense labour (mechanical joining) or extensive surface preparation and long curing cycles (adhesive bonding). As a result, the possibly of assembling structures by welding adds to the numerous advantages of thermoplastic composites over thermosets, like improved toughness, better environmental resistance, shorter processing times, non-flammability and infinite shelf life. Fusion bonding techniques