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.

Parallel strand bamboo has extensive potential applications as a structural material for construction. Studying longitudinal stress-strain relationships is essential as a means to build a constitutive law for parallel strand bamboo composites and to conduct an inelastic analysis for structural members constructed by this material. For this reason, failure modes and the damage mechanisms were investigated for tension and compression in parallel strand bamboo composites in the longitudinal direction. An analytical stress-strain formula for the parallel strand bamboo composites was developed for tension and compression related calculations. Tensile failure was caused by the damage of the longitudinal fibers and showed brittle characteristics. The compressive failure resulted from the buckling of the fibers near the damage area. In addition, three types of failure modes were observed; longitudinal buckling failure, compressive-shearing failure, and longitudinal crush failure. The stress-strain relationship in the longitudinal direction of parallel strand bamboo composites exhibited linear behaviour for tension. However, the stress-strain relationship for compression remained linear within the proportional limit, while becoming nonlinear, which can be simulated by a quadratic polynomial, once the stress exceeded the limit. The experimental data agreed well with the model predictions, showing that the present model had high prediction accuracy.

Parallel strand lumber (PSL) is an attractive structural wood composite which may have prospective use in building constructions. Conducting nonlinear analysis for the bending of PSL beams is a critical step in the determination of ultimate strength and deflection of them, which is an essential requirement of the building design philosophy based on probability of ultimate state. For the purposes of this article, an inelastic theoretical model regarding the load‐carrying capacity of the PSL bending component has been developed. Based on the uniaxial loading tests, the stress‐strain behaviors of PSL composite in the grain direction were measured. 4‐point bending experiments were also performed in this study to investigate the failure mechanism of the PSL components. The results show that the tensile stress‐strain relationship of PSL materials in the grain direction remains linear until breaking, while the compressive stress‐strain relationship exhibits nonlinear characteristics once the compressive stress exceeds the proportional limit, which can be expressed by a quadratic polynomial. The failure mode of the PSL beam can be summarized that the fibres in the top of the broken section were buckling and those in the bottom of the section were broken when failure occurred. Significant nonlinear behavior was exhibited based on the load‐deflection curves of the PSL beams. To predict the nonlinear bending performance of the PSL beams, a theoretical model that could consider the nonlinear stress‐strain relations of PSL and predict the damage modes of the PSL beams was developed. Well agreements can be observed between the results of calculations and experiments.