Mechanical Response and Multi‐Component Damage Mechanism of CFRP /Ti Hybrid Bonded/Bolted Joints Under Tensile Loading

ABSTRACT The study investigates damage progression and failure mechanisms in carbon fiber‐reinforced polymer (CFRP)/Ti hybrid bonded/bolted joints subjected to tensile loading. In contrast to previous studies focused on a single failure mode, four distinct damage mechanisms, fiber tensile damage, fiber compressive damage, matrix tensile damage, and matrix compressive damage were simultaneously quantified for individual layers with varying orientations. Additionally, the characteristics of stress distributions were summarized for each ply angle within the layup. The deformation behavior of the titanium plate under load was first examined. Subsequently, a progressive damage model based on the 3D Hashin failure criterion was developed to predict the tensile failure of the CFRP/Ti joints. The model enabled explicit prediction of intra‐laminar damage mechanisms and stress distributions within the CFRP laminate, including specific analysis of fiber and matrix tensile‐compressive failures across plies with varying orientations. Displacements of the titanium plate and bolt along the X , Y , and Z ‐axes, as well as their rotational angles about these axes, were quantified. Key findings demonstrated that CFRP ply damage initiation and progression were critically dependent on ply angle and the constraints imposed by the bolted joint. Under tensile loading, the titanium plate exhibited a maximum displacement of 0.9 mm along the Z ‐axis, while the bolt showed a peak displacement of 3.4 mm along the X ‐axis, both assemblies reached a maximum rotation angle around the Y ‐axis of −0.045° for the Ti plate and 0.115° for the bolt. The bolted joint produced a peak bending moment of approximately 3950 N·mm around the Z ‐axis.