ISSN:
1432-5225
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Summary Growth stresses originate in maturation strains, induced in cambial layers during the differentiation and the maturation of new cells, impeded by the mass of the whole trunk. To predict stresses in a stem, one must add successive incremental stresses at successively created points of the growing trunk. Usual measurements of released strains at the surface of a stem do not give the evolution of maturation strains with growth. As the assumption that states that maturation strains are constant since the beginning of secondary growth leads to singularities near the pith, an empiric pattern of variation of maturation strains along the radius is proposed, using observations about relationships between released longitudinal strain and microfibril angle. Furthermore, assuming an elastic, orthotropic behavior law and a cylindrical, sufficiently long stem, residual stresses are computed and discussed. For hardwoods, far enough from the pith, patterns of computed longitudinal and tangential stresses agree with distributions already stated by other authors although these stress components are limited near the pith. Computed radial stresses have lower levels than commonly admitted. On the other hand, stress-distributions in young softwoods are found very different, especially near the pith where the longitudinal component appears tensile and the tangential one compressive.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00229049
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