Mechanical performance analysis of transverse ultrasonic vibration‐assisted riveting for <scp>CFRP</scp> / <scp>TC4 titanium alloy</scp> heterogeneous components

Abstract The transverse ultrasonic vibration‐assisted riveting (TUVAR) technique for carbon fiber‐reinforced plastic (CFRP)/TC4 titanium alloy (TC4) components was investigated to address the challenge of ensuring reliable connections in heterogeneous materials. The forming quality, static tensile properties, failure modes, and fracture characteristics of CFRP/TC4 joints were analyzed under various TUVAR conditions. Scanning electron microscopy (SEM) and a 3D digital microscope were employed to examine the failure process and fracture mechanisms. The findings indicate that ultrasonic amplitude has a more considerable influence on relative interference and static tensile properties than riveting speed. With the driven head formed on the CFRP side, an increase in ultrasonic amplitude leads to a reduction in relative interference. At riveting speeds of 2 mm/s and 5 mm/s, the static tensile load grows as ultrasonic amplitude rises. The static tensile failure mechanisms include shear fracture of the shank and the penetration of the driven head through the CFRP hole. On the TC4 side, relative interference increases as ultrasonic amplitude increases. The static tensile load also rises with ultrasonic amplitude, with the failure mechanism being rivet shank shear fracture. Rivet‐driven heads formed on the TC4 side exhibit more consistent mechanical properties. The shear fracture behavior of the rivet shank shows a combination of brittle and ductile fracture characteristics. Highlights TUVAR process was first applied to CFRP/TC4 heterogeneous components. The response of ultrasonic amplitude is more significant than riveting speed. The direction of the driven head significantly affects joint performance.