Modeling of the viscoelastic mechano-sorptive behavior in wood

Dubois, Frédéric; Husson, Jean-Marie; Sauvat, Nicolas; Manfoumbi, Nicaise

doi:10.1007/s11043-012-9171-3

Cited by 30 publications

(17 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition to what has been said above, changes in moisture content can cause changes in the mechanical properties of wood [9,10]. If we talk about foundations, controlling moisture can be especially important.…”

Section: Introductionmentioning

confidence: 99%

Measurement of Moisture in Wood for Application in the Restoration of Old Buildings

Morón

García-Fuentevilla

García

et al. 2016

Sensors

View full text Add to dashboard Cite

There are many historic buildings whose construction is based on timber frame walls. Most buildings built during the nineteenth and early twentieth centuries were based on timber frame walls with vertical support elements. These timber frame elements are affected by their moisture content and by the passage of time. If the interaction of the timber frame walls with hygrothermal fluctuations were known, the maintenance of these buildings could be improved significantly. To determine the moisture content of wood there are two types of meters on the market: on the one hand, capacitance meters which consist of two side ends and where the moisture content is measured locally between two peaks. On the other hand, there are meters based on the variation of electromagnetic transmittance of timber, which depends on the moisture of timber. The second ones are very expensive and difficult to handle. This work presents a new non-intrusive capacitive sensor that measures the global moisture content in a section of the timber frame walls and therefore its accuracy is similar to the accuracy that can be obtained with electromagnetic transmittance meters. Additionally, as it is a capacitive sensor, it is low cost and easy to operate.

show abstract

Section: Introductionmentioning

confidence: 99%

Measurement of Moisture in Wood for Application in the Restoration of Old Buildings

Morón

García-Fuentevilla

García

et al. 2016

Sensors

View full text Add to dashboard Cite

show abstract

“…As it will be seen hereafter, this distance denotes the existence of a mechanosorptive effect. The fact that it finally disappears shows the ability of the material to cancel the mechanosorptive effect which has recently been considered as a kind of memory effect by some authors (Husson et al 2009;Dubois et al 2012). …”

Section: Mechanosorptive Tests In Relaxationmentioning

confidence: 99%

“…Based on this assumption, a model was developed where this effect is coupled with creep (Dubois et al 2005). Later on, this effect was represented by means of a 'hygrolock spring' connected to a Kelvin generalized model (Husson et al 2010;Dubois et al 2012). Besides, an alternative model was developed where the mechanism of creation of the hygrolock strain is represented by an 'active box' in which the elastic behaviour of wood is progressively tuned during a drying-moistening cycle (Colmars et al 2009).…”

Section: Introductionmentioning

confidence: 99%

Experimental study of the mechanosorptive behaviour of softwood in relaxation

et al. 2016

View full text Add to dashboard Cite

In softwood material, the coupling between mechanical loading and hydric state is known as the mechanosorptive effect. However, the coupling with viscoelastic effect remains unclear so far, especially when the loading is controlled by strain. In this context, the present paper is focused on the process of creation and recovery of 'hygrolock' behaviour, i.e. a stress locking effect which occurs in a phase of drying under load. For this purpose, several relaxation tests were first performed on small-scale silver fir specimens in order to express the relaxation function in terms of the ambient humidity. Then, two mechanosorptive tests were carried out in order to induce hygrolock stresses in the same sample loaded in sustained strain condition, and subjected to cyclically varying humidity. Based on the assumption of stress partition, the analysis of the test results clearly shows the existence of a hygrolock stress. From these experimental evidences, a law is finally proposed to describe the evolution of the hygrolock stress in terms of the hydric state of the softwood material.Electronic supplementary material The online version of this article (

show abstract

“…By using incremental formulation deduced from equation 5, Dubois (2012) gave the formulation of a discrete time-dependant behavior including hygrolock effect for implementation in finite element code.…”

Section: Hygrolock Modelsmentioning

confidence: 99%

One-dimensional discrete formulation of a hygrolock model for wood hygromechanics

Colmars

Dubois

Gril

2013

Mech Time-Depend Mater

View full text Add to dashboard Cite

International audiencea new 1D discrete formulation of hygrolock models is proposed for modeling wood time-dependent behavior. This discrete formulation is compared to an integral formulation presented in a previously published paper. Simulations with various humidity cycles are performed under constant stress (creep) or constant strain (relaxation) using first a hygrolock spring and then a generalized Kelvin-Voigt model with a time-spectral distribution of hygrolocks springs. The discrete formulation presented here, based on original idea of mixed series/parallel rheological model, is shown to be very practical for implementation in scientific numerical codes. In order to compensate a lack of complete data-set on wood material, a generic time and moisture-dependent material is proposed to compare the various models: this dataset could be re-used in other studies. Finally the relevance of hygrolock models for wood time-dependent behavior is discussed: it appears that hygrolock models suits well to the upper part of wood hygroscopic domain, whereas further hypothesis should be tested for dry domain. A judicious choice in moisture activation of material parameters, combined with the blocking effect of hygrolock, agree with recent experimental results on simplifying the description of so-called ++ effect

show abstract

Modeling of the viscoelastic mechano-sorptive behavior in wood

Cited by 30 publications

References 29 publications

Measurement of Moisture in Wood for Application in the Restoration of Old Buildings

Measurement of Moisture in Wood for Application in the Restoration of Old Buildings

Experimental study of the mechanosorptive behaviour of softwood in relaxation

One-dimensional discrete formulation of a hygrolock model for wood hygromechanics

Contact Info

Product

Resources

About