000018261 001__ 18261
000018261 005__ 20170118182214.0
000018261 04107 $$aeng
000018261 046__ $$k2017-01-09
000018261 100__ $$aElghazouli, Ahmed Y.
000018261 24500 $$aPlasticity-Damage Material Constitutive Model for Timber Subjected To Cyclic Loading

000018261 24630 $$n16.$$pProceedings of the 16th World Conference on Earthquake Engineering
000018261 260__ $$b
000018261 506__ $$arestricted
000018261 520__ $$2eng$$aA plasticity-damage constitutive model for timber, which builds upon previous models developed for other quasi-brittle materials like concrete, is proposed in this article. Timber failure modes can be broadly defined as ductile failure due to compression stresses and brittle failure due to the combination of shear and tension stresses. This paper presents the formulation and implementation of a detailed and practical material constitutive model for timber subjected to cyclic loading, which can deal with both types of failure modes. Due to the anisotropic characteristics of timber, Hill’s expression was used as equivalent stress damage criterion for both compressive and shear-tensile failure. The damage evolution process starts once the failure criterion is reached, and is handled by two different monotonically increasing functions of the equivalent stresses for tension (exponential softening) and compression (perfect plasticity). The damage variables associated with these functions gradually reduce the timber stiffness material parameters (elastic moduli and shear moduli). The main advantage of incorporating a continuous damage model for timber is to capture the post-elastic stiffness degradation and thus enable an accurate prediction of experimental results. On the other hand, plasticity allows the incorporation of timber plastic flow in compression and its associated permanent deformations. This study discusses the theoretical framework and consistency of both models and presents the equations required for their coupling and implementation. Preliminary numerical results are presented for uniaxial cyclic loading in both directions, parallel and perpendicular to the grain. It is shown that tensile softening brittle failure, stiffness cyclic degradation and recovery after load-reversal, in addition to compressive permanent plastic deformation, are key characteristics of the non-linear behaviour of timber. These characteristics can be captured by the proposed constitutive model, which represents the first step towards a faithful estimation of the earthquake-induced collapse capacity of timber structures.

000018261 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000018261 653__ $$atimber; plasticity; damage; cyclic loading;

000018261 7112_ $$a16th World Conference on Earthquake Engineering$$cSantiago (CL)$$d2017-01-09 / 2017-01-13$$gWCEE16
000018261 720__ $$aElghazouli, Ahmed Y.$$iZapata, Luis Fernando Sirumbal$$iMálaga-Chuquitaype, Christian
000018261 8560_ $$ffischerc@itam.cas.cz
000018261 8564_ $$s461049$$uhttps://invenio.itam.cas.cz/record/18261/files/1122.pdf$$yOriginal version of the author's contribution as presented on USB, paper 1122.
000018261 962__ $$r16048
000018261 980__ $$aPAPER