Laminated bamboo lumber in compression perpendicular to the grain direction: Experimental investigation and the finite element analysis

Localized damage may occur due to the fact that laminated bamboo lumber (LBL) has a lower compressive strength perpendicular to the grain direction than it does parallel to the grain. In this study, the transverse compressive performance of LBL under entire-surface compression and local-surface compression is investigated. Load–displacement curves, stress–strain relationship, detailed failure modes, and basic mechanical properties are obtained. The results show that despite the compressive strength and elastic modulus being nearly the same in the two transverse orientations, the failure patterns are distinct due to the layer structure. Ramberg-Osgood relation is utilized to fit the stress–strain curves. Proportional limit strength is determined indicating that specimens compressed locally have a greater load-bearing capability. Based on the finite element analysis and theoretical study, the mechanism of the enhancement in proportional limit strength is revealed. Equations for determining the bearing load of a specimen under local compression in the elastic stage are derived from the simulation data and logit model, considering the contact length and geometric size of the specimen. Additionally, parametric tests are conducted to determine the effect of bearing shape, bearing area, and loading mode on the stress distribution and bearing capacity.