Measurement of surface growth stress in Eucalyptus nitens Maiden by splitting a log along its axis

Holzforschung ◽  
2010 ◽  
Vol 64 (2) ◽  
Author(s):  
Shakti Chauhan ◽  
Kenneth Entwistle
Keyword(s):  
Splitting Method ◽  
Circular Cross Section ◽  
Growth Stress ◽  
Surface Growth ◽  
Longitudinal Growth ◽  
Growth Strain ◽  
Eucalyptus Nitens ◽  
Growth Stresses ◽  
The Relationship ◽  
Longitudinal Growth Strain

Abstract When a log is sawn along the length, an outward bending or deflection of two half rounds arises from the release of growth stresses in the log. The relationship between this outward bending and the peripheral longitudinal growth strain in logs from a 10-year-old Eucalyptus nitens plantation was investigated. In total, 63 trees were felled and two logs (one bottom and an upper log) were cut from each felled tree. A strong association was observed between the measured longitudinal growth strain and the outward bending produced by splitting the log along its axis. A mathematical model was developed that enables calculation of the relationship between the surface axial growth stress and the opening of the split log. This involves calculation of the lateral deflection of a tapered cantilever beam of semi-circular cross-section under a known bending moment. The relationship between the opening of the slit log and the surface axial stress showed good agreement with the measured data on 126 logs. The model equation is effective in predicting the growth stress from the magnitude of the log distortion. This log sawing or splitting method is quick and reliable for assessing the surface growth stresses in small diameter trees. It could have potential in breeding programs for identifying families or clones for low-growth stresses of superior eucalypts for sawn timber production.

Longitudinal growth strain as a log and wood quality predictor for plantation-grown Eucalyptus nitens sawlogs

2010 ◽  
Vol 45 (1) ◽  
pp. 15-34 ◽  
Author(s):  
Juan Valencia ◽  
Chris Harwood ◽  
Russell Washusen ◽  
Andrew Morrow ◽  
Matthew Wood ◽  
...  
Keyword(s):  
Wood Quality ◽  
Longitudinal Growth ◽  
Growth Strain ◽  
Eucalyptus Nitens ◽  
Longitudinal Growth Strain

scholarly journals Growth Stresses are Highly Controlled by the Amount of G-Layer in Poplar Tension Wood

IAWA Journal ◽  
2008 ◽  
Vol 29 (3) ◽  
pp. 237-246 ◽  
Author(s):  
Chang-Hua Fang ◽  
Bruno Clair ◽  
Joseph Gril ◽  
Sheng-Quan Liu
Keyword(s):  
Tension Wood ◽  
Growth Stress ◽  
Strain Level ◽  
Longitudinal Growth ◽  
Growth Strain ◽  
Growth Stresses ◽  
Tissue Area

To determine how gelatinous fibres and gelatinous layers contribute to the magnitude of longitudinal growth stress in tension wood, anatomical measurements of gelatinous fibres were carried out on poplar tension wood (Populus I4551). It was found that (a) no gelatinous fibres were observed under a growth strain level of 0.06 to 0.08%; (b) almost 100% of the non-conductive tissues contained gelatinous fibres above a growth strain level of 0.15 to 0.19%; and (c) the area of fibres, the area of fibres with gelatinous layers per unit of tissue area, and the thickness of the gelatinous layers predominantly influenced the magnitude of growth stress

Some Tree Growth – Wood Property Relationships of Eucalypts

1975 ◽  
Vol 5 (3) ◽  
pp. 424-432 ◽  
Author(s):  
J. E. Nicholson ◽  
W. E. Hillis ◽  
N. Ditchburne
Keyword(s):  
Wood Property ◽  
Basic Density ◽  
Wood Properties ◽  
Reaction Wood ◽  
Growth Strain ◽  
Fiber Structure ◽  
Tree Crown ◽  
Stem Form ◽  
The Relationship ◽  
Longitudinal Growth Strain

The relationship between level of longitudinal growth strain and stress, modulus of elasticity, basic density, volumetric shrinkage, fiber classification, and stem form was investigated with 10 Eucalyptusregnans regrowth trees. Close relationships were observed. It is suggested that variations in these properties within trees are closely controlled, possibly to enable optimum positioning of the tree crown in relation to its immediate environment. The concept of fiber structure varying as a response to environment is supported by the observed variation in wood properties within and between trees of this species. The often-reported association between eccentric radial growth and reaction wood was not substantiated in this study.The data indicate that if economically justifiable, it would be possible to segregate trees that are likely to contain material that is hard to season.

scholarly journals Relationships and estimates of longitudinal growth stress in Eucalyptus dunnii at different ages

2008 ◽  
Vol 32 (4) ◽  
pp. 723-729 ◽  
Author(s):  
Paulo Fernando Trugilho ◽  
José Tarcísio da Silva Oliveira
Keyword(s):  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Basic Density ◽  
Longitudinal Direction ◽  
Growth Stress ◽  
Longitudinal Growth ◽  
Growth Stresses ◽  
Dynamic Modulus Of Elasticity ◽  
Eucalyptus Dunnii ◽  
Standing Trees

The objective of this study was to obtain estimates of longitudinal growth stresses in standing trees of the Eucalyptus dunnii Maiden at eight, thirteen, fifteen and nineteen years of age and to determine their relationships with wood characteristics. The longitudinal growth stresses were indirectly measured by the "CIRAD-Forêt" method and estimated from both the dynamic modulus of elasticity and the modulus of elasticity in tension parallel to the grain. The longitudinal residual strain (LRS) and the estimates of the longitudinal growth stresses tended to increase with the age of the material. The LRS correlated positively and significantly with all the growth stresses estimates. The largestes magnitudes were at 13, 15 and 19 years of age. The basic density presented high, positive and significant correlations with the dynamic modulus of elasticity, estimated in the longitudinal direction, for wood saturated and at 12% moisture content, for all the ages assessed. All the growth stresses estimates presented high, positive and significant correlations between themselves.

Fracture Energy of Refractories

2012 ◽  
Vol 503-504 ◽  
pp. 1142-1145
Author(s):  
Fan Qian ◽  
Hong Xia Li ◽  
Guo Qi Liu ◽  
Wen Gang Yang ◽  
Jin Song Yang ◽  
...  
Keyword(s):  
High Temperature ◽  
Fracture Energy ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Splitting Method ◽  
Research Status ◽  
Shock Resistance ◽  
The Relationship ◽  
Wedge Splitting

This paper introduce the relationship between fracture energy of refractories and its thermal shock resistance, and research status about fracture energy of refractories. It shows that investigation on fracture energy of refractories at high temperature is positive significance for evaluation of thermal shock resistance, and wedge splitting method for fracture energy of refractories is an effective method.

Branches versus stems in woody plants: control of branch diameter growth and angle

1998 ◽  
Vol 76 (11) ◽  
pp. 1852-1856 ◽  
Author(s):  
Brayton F Wilson
Keyword(s):  
Acer Rubrum ◽  
Growth Stress ◽  
Diameter Growth ◽  
Reaction Wood ◽  
Differential Growth ◽  
Lateral Shoot ◽  
Branch Diameter ◽  
Growth Stresses ◽  
Branch Angle ◽  
Apical Control

The results of three studies at different stages of branch development demonstrated the importance of apical control of diameter growth in both stem formation and branch angle. Diameter growth is controlled by competition between branches and the stem for branch-produced photosynthate. Apical control of branch angle occurs only in species that can produce differential growth stresses. In those species, upward bending is largely regulated by the amount of branch diameter growth. The first study followed stem formation from current shoots in Kalmia latifolia L., a shrub without terminal buds or apical control of branch angle. When several current or older shoots were competing, the longest, most distal lateral shoot usually became the stem. Shoot angle was poorly correlated with eventual dominance. A more proximal lateral shoot on the underside of a leaning parent became the longest, dominant lateral in 24% of the parent shoots. The second study used stem girdles to test the hypothesis that the subjacent stem competes with the branch for branch-produced photosynthate. Results from Pinus strobus L. supported the hypothesis, but results from Betula lenta L. and Acer rubrum L. did not. The third study removed apical control from branches of six forest-shrub species by cutting off the stem above the branch. Branches of all species increased diameter growth after cutting the stem, but only branches of Ilex verticillata (L.) Gray, Hamamelis virginiana L., and Cornus amomum Mill. developed differential growth stress and bent upward. Treated branches of Gaylusaccia baccata (Wang.) K. Koch, Viburnum cassinoides L., and K. latifolia sagged as much as controls.Key words: apical control, diameter growth, branch angle, growth stress, reaction wood.

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