A shear strength criterion for the buckling analysis of CLT walls

Abstract

The proper sizing of Cross Laminated Timber (CLT) walls for the construction of high rise buildings requires to take into account their low shear stiffness and their viscoelastic properties and to integrate them into the framework of actual building codes which are all based upon Ayrton-Perry approach of imperfect columns. The present paper starts thus by recalling the framework of Linear Buckling Analysis of shear weak columns using the Timoshenko beam model. Then, Ayrton-Perry approach of the buckling of imperfect columns is introduced and used to develop a normal stress strength criterion for CLT walls but also an additional shear strength criterion. Both criteria are compared for three characteristic sizes of initial imperfections. Afterwards, orthotropic creep is introduced and its effect on long term stability of shear weak members is investigated and an extension of the previous criteria to long term behaviour is developed. Throughout the study, three numerical examples are used for illustration (a low strength panel, a high strength and an aerated panel) revealing the importance of proposed shear strength verification and the need of experimental characterisation.

Buckling Analyses of Cross Laminated Timber Panels

“…In this framework, native hardwoods species such as beech which is extensively available in European forests [13] proved to have relevant mechanical features for CLT structural applications [14]. Many researches have been also conducted to better understand the CLT behavior under different load conditions as bending [15], compression [16,17], and shear [18,19], nevertheless the CLT in-plane behavior under compressive loads, leading to column buckling is currently poorly investigated as for softwood [20,21] as for hardwood species. For timber structural components and systems, stability issues have a critical role in design procedures, due to the challenging trend of modern applications towards the construction of high-rise timber buildings as well for the intrinsic material's nature.…”

The Effect of the Bearing Width on the Buckling Capacity of Partially Loaded CLT Member

“…Pina et al [9] studied the influence of the number of layers and openings on the buckling capacity of CLT members via a multi-scale finite element model. Perret et al [10] introduced the Ayrton-Perry approach for buckling of a column with imperfections by adding the shear strength criterion, and the effect of creep on the buckling capacity was investigated. Huo et al [11] proposed formulas for calculating the stability coefficient applicable to CLT members based on the available formulas for general timber members by regressing the material parameters and using the effective moment of inertia and section areas.…”