Journal ArticleDOI
Stress relaxation of wood at several levels of strain
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In this article, a model consisting of an isolated spring in parallel with a spring and dashpot in series was used as an aid in the derivation of equations describing stress relaxation.Abstract:
Stress relaxation tests were performed with six tropical American species. Stress relaxation was not found to be a linear function of strain at any level of strain. At qual low levels of strain, stress relaxation in compression was much greater than in tension. A mechanical model consisting of an isolated spring in parallel with a spring and dashpot in series was used as an aid in the derivation of equations describing stress relaxation. An attempt to apply Newtonian viscous theory to the model was unsuccessful in accounting for rate of relaxation. However, when the hyperbolic sine law of viscous flow was applied, mathematically derived curves fitted the data very well. Stress relaxation appears to be related to “departure strain” which may be obtained readily from static stress strain diagrams.read more
Citations
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Journal ArticleDOI
Wood as a linear orthotropic viscoelastic material
Arno P. Schniewind,J. D. Barrett +1 more
TL;DR: In this article, the principal components of the creep compliance tensor in the radial longitudinal and the tangential longitudinal planes of Douglas-fir at 10 percent moisture content were measured.
Journal ArticleDOI
Linearity and non-linearity in mechano-sorptive creep of softwood in compression and bending
TL;DR: In this paper, it was shown that the nonlinearity of softwood in axial mechano-sorptive creep during moisture cycling can be characterised as departure from linear behaviour.
Journal ArticleDOI
Mechanical Behavior of High Polymers
TL;DR: Alfrey as discussed by the authors provides a concise treatment of the classical theory of elasticity, flow in Newtonian and non-Newtonian liquids, plasticity and thixotropy, and simpler types of visco-elastic behaviour.
Journal ArticleDOI
Load-carrying capacity of steel-to-timber joints with a pretensioned bolt
TL;DR: In this article, an extended yield model that considers the fastener's pretension force was presented, where the load-carrying capacity was defined as the load at a slip of 15 mm and the ultimate fastener bending angle at the yielded cross section equivalent to this joint slip, which was iteratively evaluated in numerical analyses.
Journal ArticleDOI
Thermal stability of organo-montmorillonite-modified wood flour/poly(lactic acid) composites
Ru Liu,Yao Peng,Jinzhen Cao +2 more
TL;DR: In this article, wood flour was modified using organo-montmorillonite (OMMT) at four different concentrations (0.5, 1.0, 2.0 and 4.0 wt%, respectively) and didecyl dimethyl ammonium chloride (DDAC) in a two-step process.
References
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Book
Viscoelastic properties of polymers
TL;DR: In this article, the authors describe the nature of Viscoelastic behavior of polymeric systems and approximate relations among the linear Viscoels and approximate interrelations among the Viscelastic Functions.
Journal ArticleDOI
Mechanical Properties of Polymeric Materials
Arthur V. Tobolsky,Henry Eyring +1 more
TL;DR: In this paper, a molecular model in terms of which the elastic viscous properties of rubber-like substances can be interpreted is presented, and experiments on stress relaxation at constant extension, creep under constant load, extrusion, vibration, and breaking are discussed.
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