Lateral load capacity of WikiHouse composite walls from CNC cut timber panels

Abstract

Computer-numerical-control (CNC) fabrication of interlocking-plate timber structures is a novel construction method that allows to build structural elements without mechanical fasteners: the load transfer mainly relies on direct contact and friction between the composing panels. In this work, the lateral load capacity of shear walls formed from interlocking CNC cut plywood elements is investigated by means of experimental testing and analytical modelling. The experimental campaign comprises four full scale 5.4 m x 3.1 m wall specimens with and without window openings, and component tests on shear connectors and pegged connections which resist uplift at the base of the wall. The results obtained from the connection tests were used in combination with a proposed analytical model to simulate the force-displacement response of the full scale specimens. Results show that the behaviour of the walls is governed by the stiffness and capacity properties of the connectors. The elastic analytical model of the racking behaviour of the wall captured the stiffness of each of the specimens well once a global factor is applied to capture the effect of joint tolerance and other rigid body rotations, and the lateral load capacity of the walls fell within the range of predictions.