An Experimental Study on the Tensile Behaviors of Ultrasonic Welded T-joints for Polyamide Composite

In this paper, an experimental investigation on ultrasonic welding of polyamide composites reinforced with glass fiber has been carried out. The effect of ultrasonic welding parameters, such as welding time, air pressure, hold time and the amount of glass fiber in the composite on tensile strength of weld joints were determined using response surface methodology. This methodology was applied for developing a mathematical model which can predict the main effects of the above parameters and their impacts on tensile strength of T-welded ultrasonic joints in 4-mm thick polyamide composite sheets. The analysis of variance was performed to check the adequacy of the developed model. A comparison was also made between the predicted and actual results. The results showed that a maximum failure force of about 4759 N is obtained when vibration amplitude, air pressure welding time, holding time and amount of glass fiber are 35 microns, 3.6 bar, 1.84 seconds, 0.9 seconds and 41 percent, respectively .The joint strength of welded parts increased with the fiber content in the composites.