Abstract
A statistically designed experimental approach was used to determine the optimum weld processing parameter values for a lap shear coupon prepared from a resis tance welded dual-polymer material system. The adherends used were 16-ply quasi isotropic laminates formed from T-750 graphite and polyarylsulfone prepreg (Radel®) with neat polysulfone comolded to each surface. The heating elements were made from a single layer of the Radel® prepreg with neat polysulfone comolded on each side. Electrical con nections were made through an expanded foil mesh conductor tab that was ultrasonically attached to each end of the heating element. The design-of-experiment approach was used for the experimental set-up and analysis. A series of response surface plots was prepared that allowed the optimum processing parameter values to be identified. Photomicrographs and C-scans were prepared from the welded region and compared to the lap shear strength values obtained. The relationship between the bondline thickness and the lap shear strength was also examined. The experimental results showed that maximum joint strengths were obtained at temperatures exceeding the glass transition temperatures (Tg ) of the polymers.