Mode I fracture behavior of unidirectional bamboo laminate and its applications to the estimation of bamboo-steel-bamboo connections’ bearing capacities

Abstract

Fracture caused by crack propagation is prevalent in bamboo laminate. Mode I fracture of bamboo laminate in which the fracture surface is composed of multilayer strips with fracture along the Tangential-Longitudinal (T-L) direction was studied. The load-crack opening mouth displacement (CMOD) curves of Mode I fracture, and the post-peak behavior of bamboo laminate were analyzed. The Mode I fracture toughness was calculated based on the modified beam theory. The effect of the bamboo node on fracture toughness was studied. The Mode I fracture toughness of bamboo laminate increases with the crack growth due to bamboo nodes. The toughening mechanism is the interlocking effect and fiber bridging on the uneven fracture surface. The mean value of the Mode I fracture toughness of unidirectional bamboo laminate panels along the y-x direction of the unidirectional bamboo laminate was suggested to be 225.7 J/m2 for the estimation of bamboo-steel-bamboo connections' bearing capacities. Based on the measured fracture properties of bamboo laminate and the fracture mechanics models, the brittle bearing capacities of the bamboo-steel-bamboo connections were discussed at the end of this research.