Mode-I interlaminar fracture behavior of laminated bamboo composites was characterized by mechanical testing in a bonded double cantilever beam configuration. No obvious fiber bridging was observed during the test. At the front of crack tip, nonlinear response was relatively small and negligible. The failure mode of laminated bamboo composites was mainly governed by brittle fracture. Mode-I interlaminar fracture toughness ([ ]) calculated using the modified beam theory was 501.08 J/m ² . Besides, numerical simulation combined with cohesive elements was used to simulate the mode-I interlaminar fracture behavior. A direct method for the determination of cohesive parameters without recourse to iterative fitting was presented in detail. The applicability and effectiveness of this method for interpretation of the fracture behavior of laminated bamboo composites were verified by comparing numerical predictions with experimental results.

High-strength steels (HSSs) with nominal yield stress not less than 460 MPa have been increasingly employed in bridge structures. Compared with SM490 normal-strength steel (NSS), HSSs, including SBHS500 and SM570, have higher strength but lower ductility, and brittle fracture can easily occur in the HSSs members with notches. Therefore, 48 tension specimens with U-notch or V-notch made of SBHS500, SM570 and SM490 structural steels are carried out. The influences of notch depth, U-notch radius, V-notch degree and chemical composition on the mechanical and fracture performances of the steel specimens are investigated. It is concluded from experimental results that SBHS500 and SM570 HSSs with higher yield stress have a relatively higher elastic stress concentration factor, crack initiation appears earlier, and brittle fracture is more likely to occur. Compared to SM570 HSS, SBHS500 HSS has better weldability.