An Investigation Into the Dynamic Response and Failure Mechanism of CFRTP / Ti6Al4V Hybrid Welded/Bolted Joints Under Low‐Velocity Impact

ABSTRACT With the increasing demand for high‐performance and lightweight structures in the aerospace, the integration of carbon fiber reinforced thermoplastic (CFRTP) and titanium alloys has become a research priority. To explore the potential application of CFRTP, this study proposes a CFRTP/Ti6Al4V hybrid welded/bolted joint (HWBJ). The effects of impact energy (15/20/25/30 J) and impact surface (CFRTP/Ti6Al4V) on the mechanical performance and failure behavior of the HWBJ were investigated. The results indicate that, regardless of the impact surface, increasing impact energy leads to higher values of key impact response parameters (peak force, response time, maximum displacement, residual displacement, absorbed energy and peak energy moment) and larger delamination damage projection area, while the residual strength of the weld interface decreases. Using CFRTP as the impact surface reduces the loss of weld interface residual strength by 8% compared to the Ti6Al4V surface observed at 30 J. Low‐energy impacts (15–20 J) do not cause specimen deflection, while high‐energy impacts (25–30 J) induce significant deflection reaching a maximum of 7°. For CFRTP under tensile after impact (TAI) loading, damage at the impact location extends to the edges of the impact point at 25 J and penetrates the entire laminate at 30 J. 25 J became the anomalous failure energy threshold for HWBJ. Except for 30 J impacts on CFRTP, the residual strength in the bolt‐bearing phase of other specimens remains similar to that of undamaged specimens (12780N). This study provides a solid technical basis and experimental paradigm for the design of heterogeneous material joints.