Plastic models for analysis of fully anchored light-frame timber shear walls

Abstract

In order to stabilise timber-framed buildings against lateral loads, the diaphragm action of roofs, floors and walls is often used. This paper deals with plastic analysis models for fully anchored sheathed shear walls. The models are based on the assumption of plastic load–slip relations for the sheathing-to-framing joints. Only static loads are considered. The basic structural behaviour and assumptions for the plastic models are elucidated. Both upper and lower bound methods are applied. The load-bearing capacity and the deformation of the shear walls in the ultimate and serviceability limit states, respectively, are derived. Both a discrete point description and a continuous flow per unit length modelling of the fasteners are discussed. Also, the forces and displacements of the fasteners and sheathing are derived. The influence of flexible framing members and shear deformations in the sheets, and also the effect of vertical loads on the shear wall, both with respect to tilting and second order effects, on the horizontal load-bearing capacity and displacement are evaluated. The stress distribution and the reaction forces at the ends of the different framing members are derived. The elastic model is experimentally verified and an illustrative example is given. The main objective of this work is to contribute to a better understanding of the structural behaviour of these fully anchored walls and form the basis for establishing a new plastic design method for partially anchored shear walls, i.e. a design method capable of analysing the more practical conditions of no or partial anchorage of the studs and/or bottom rail in real structures.