Abstract This paper reviews recent findings on wood–water interaction and puts them into context of established knowledge in the field. Several new challenge prevalent theories are critically discussed an attempt to advance current highlight gaps. The focus this review is put water broadest concept wood products, that is, living tree not considered. Moreover, covers basic relation, states transitions. Secondary effects such as ability alter physical properties only cases where there...

Abstract This paper presents a study and refinement of the sorption rate model in so-called multi-Fickian or multi-phase model. type describes complex moisture transport system wood, which consists separate water vapor bound-water diffusion interacting through sorption. At high relative humidities, effect this becomes apparent, since single Fickian equation fails to behavior, it has been referred as non-Fickian anomalous behavior. low slow fast allow simplification be modeled by equation. To...

Abstract The equilibrium moisture content in wood depends not only on the current relative humidity ambient air, but also history of variations. This hysteresis dependence sorption implies that worst case for a given may deviate by 30–35%. While researchers seem to have reached general agreement hypothesis phenomenon, few models describing phenomenon are available. Current such as independent domain model numerical deficiencies and drawbacks. paper presents new model, which mathematically...

Abstract Moisture transport in an open porous hygroscopic material such as wood is a complex system of coupled processes. For seasoned natural climate three fully processes active the moisture are readily identified: (1) diffusion vapor pores; (2) phase change from one state to another, also called sorption; and (3) bound water tissue (in cell wall). A mathematical model for predicting given condition must at least consider dominating simultaneously be considered accurate. In this study,...

Abstract In the cellular structure of wood, bound-water diffusion and water-vapor interact via sorption in a complex moisture-transportation system. At low relative humidities, moisture transport may be modeled by Fickian equation with good approximation. higher slow faster cause effects, which have been referred to as non-Fickian or anomalous, they cannot one equation. Previous research has demonstrated that set coupled equations, namely multi-Fickian model, can represent this behavior. The...

Abstract The time-dependent mechanical behaviour (TDMB) of softwood is relevant, e.g., when wood used as building material where the properties must be predicted for decades ahead. established mathematical models should able to predict behaviour. However, these are not always based on actual physical processes causing and interpretation their input parameters difficult. present study describes TDMB a tissue its individual tracheids. A model constructed with local coordinate system that...

Abstract A method to determine the internal stress state across grain of glued laminated wood (glulam), as well experimental equipment for measuring released deformation are described in this paper. The is calculated from measured deformations, which by a contact free based on digital camera technique. Non-destructive measurement modulus elasticity cross-grain direction presented and correlation between dynamic static shown. Results single specimen with induced moisture gradient show that...

Abstract The macroscopic formulation of moisture transport in wood below the fiber saturation point has motivated many research efforts past two decades. Many experiments demonstrated difference steady state and transient inadequacy models derived for when used to describe processes. A suitable modeling approach was found by distinguishing between phases water wood, namely bound cell walls vapor lumens. Such are capable reproducing processes, but physical origin coupling remains unclear. In...

Three coupled two-dimensional viscoelastic creep models for orthotropic material are analyzed. The of different complexity mathematically formulated and implemented in a finite element software. Required parameters determined by calibration procedure, where numerical results compared against experimentally obtained strains caused tensile or shear loading. Finally, comparison method is used to evaluate the accuracy strain predictions each particular model. analysis shows that all able...

Rheological behavior of wood under uniaxial compression along and perpendicular to the grain in constant environment was examined. Tests with deformation rate until failure stress relaxation tests applied stepwise were carried out. The experimental results showed nonlinear material over time that got more prominent high levels. Considerable amount relaxed during applying deformation. Wood experienced greater than it. Three rheological models for orthotropic calibrated experimentally...

Abstract A hygro-mechanical (H-M) analysis of a wooden specimen sustaining mechanical load while subjected to varying relative humidity was performed predict the long-term rheological behavior wood. The numerical based on experimental results total strains, monitored in two orthotropic material directions oak wood specimens under constant uniaxial compression and with moisture content (MC) variation. For analysis, multi-Fickian transport model (MFMTM) used obtain temporal spatial MC fields,...

A theory on the lateral load-carrying capacity of timber connections with slender fasteners is presented. The base coupled mechanical phenomena acting in connection, while wood and fastener deform yield prior to failure. objective derive a sufficient description actions responses which have determining influence fasteners. Model assumptions are discussed made, but simplifications left out. Even so, simple mathematical equations describing derived from equilibrium deformed fastener. herein...

Load-bearing capacity of slender dowel-type fasteners round ring-shank nails and U-shaped connectors (U-conn:s) square cross-sectional nail thread used as connections in Timber-Concrete Composite structures have been studied, experimentally with two different theoretical models. Tensile strength withdrawal embedment timber were tested evaluated. The parameters for calculation the plastic hinge location fastener on side load-bearing connections. For this, both European Yield Model known from...