Mechanical Properties and Damage Modes of Composite Pre‐Tightened Teeth Joints: A Combined Experimental and Numerical Study

ABSTRACT The advancement of large‐span, high‐load composite lightweight emergency bridges necessitates enhanced joint bearing capacity in composite structures. The study proposes a new type of pre‐tightened tooth joint with an inner and outer sleeve for joint force transmission, improving upon conventional designs through optimized force transmission mechanisms. Experimental and numerical investigations were conducted on carbon/glass hybrid fiber‐reinforced composite joints (200 mm diameter, 8 mm wall thickness) to assess ultimate load‐bearing performance and failure characteristics under tensile/compressive loading. A progressive damage model was established using Hashin's failure criterion, with validation achieved through experimental‐numerical correlation analysis. Results demonstrate 11.2% and 38.9% increases in compressive and tensile ultimate bearing capacities, respectively, compared to traditional joints. Crucially, failure modes transitioned from interlaminar shear failure at composite teeth in conventional joints to compressive pipe failure at the primary tooth in modified configurations under compression, while maintaining dominance of interlaminar shear failure under tension. The study reveals that the proposed new connection configurations have higher ultimate bearing capacity and provide a reference for the design of composite structural connections.