Nondestructive Assessment of Flexural and Tensile Properties for Southern Pine Structural Lumber
Nondestructive Assessment of Flexural and Tensile Properties for Southern Pine Structural Lumber

Author: Marly Gabriela Carmona Uzcategui

Publisher:

Published: 2022

Total Pages: 0

ISBN-13:

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The flexural and tensile properties of visually graded southern yellow pine lumber were modeled. Longitudinal and transverse vibration techniques and proof-loading bending tests were used to assess the flexural and tensile properties of southern pine lumber. The properties evaluated were dynamic modulus of elasticity (dMOE), static modulus of elasticity (Eb), tension modulus of elasticity (Et), and ultimate tensile stress (UTS). The tensile properties were evaluated in the direction parallel to the grain. This study presents the results of tests conducted on No. 2 2 × 6 and 2 × 10 southern pine lumber of two different lengths (14 ft. and 16 ft.). The results of the analysis show that nondestructive testing techniques are excellent to assess Et and Eb. Moderate relationships were found between dMOE and UTS and between Eb and UTS. Improvements in the prediction of UTS were done with the inclusion of additional parameters into the model. The combination of dMOE, density, and frequency domain area (FDA) generated the highest coefficient of determination for UTS. The distributions of flexural and tensile properties were analyzed for the goodness of fit. Normal distribution was found for Eb data whereas the lognormal distribution was the best fit for the tensile properties.

Rapid Non-destructive Assessment of Southern Yellow Pine Lumber Properties by Near Infrared Spectroscopy
Rapid Non-destructive Assessment of Southern Yellow Pine Lumber Properties by Near Infrared Spectroscopy

Author:

Publisher:

Published: 2012

Total Pages:

ISBN-13:

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Over the last several years questions about the strength of structural lumber have been raised. The purpose of this study was to examine the relationship between physically measured wood properties using Near Infrared spectroscopy. Physical properties were determined from (2 x 4 x 2 in.) cut samples. Destructive mechanical testing was performed on 744; 8 feet long, No.2 grade 2x4's. Diffuse reflectance NIR spectra was collected from the cross-sectional face of each block using FOSS NIR Systems Inc. Model 5000 scanning spectrometer. Calibrations were then created between measured properties and NIR estimates. Density, specific gravity, latewood percentage, MOE and MOR had coefficient of determinations of 0.78, 0.56, 0.02, 0.56, and 0.48 respectively. The low correlation is likely caused by the grade of lumber. Because No.2 lumber has considerable knots, they were the determining factor in strength and stiffness; these results would likely not be similar in a higher grade lumber.

Nondestructive Evaluation of the Tensile Properties of Structural Lumber from the Spruce-pine-fir Species Grouping
Nondestructive Evaluation of the Tensile Properties of Structural Lumber from the Spruce-pine-fir Species Grouping

Author: Nusret As

Publisher:

Published: 2020

Total Pages: 12

ISBN-13:

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This study was undertaken to examine the relationship between lumber grain angle and the energy loss characteristics of structural lumber. A random sample of 100 spruce–pine–fir lumber specimens was obtained from a local lumber yard. Grain angle was measured at numerous locations for each specimen with equipment that uses a dielectric nondestructive testing technique. A commonly used free transverse vibration test, in which the specimens were simply supported in a flatwise bending mode, was used to determine the energy loss characteristics of the specimens. Increases in grain angle resulted in greater energy loss. A statisically significant positive correlative relationship was found between grain angle and energy loss. More importantly, based on results from this study, energy loss measurements may be useful for detecting lumber with low strength values.

Nondestructive Evaluation of the Tensile Properties of Structural Lumber from the Spruce-pine-fir Species Grouping
Nondestructive Evaluation of the Tensile Properties of Structural Lumber from the Spruce-pine-fir Species Grouping

Author: Nusret As

Publisher:

Published: 2020

Total Pages: 12

ISBN-13:

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The study summarized in this research note was conducted to examine the relationships between nondestructive evaluation (NDE) parameters, tensile modulus of elasticity (MOE), and strength of spruce–pine–fir structural lumber. Samples were procured from a local lumber yard using a random selection process and were conditioned at the USDA Forest Service, Forest Products Laboratory, to 10% equilibrium moisture content. Static bending and vibration (transverse and longitudinal) nondestructive tests were conducted on each specimen and MOE was calculated. The relationship between static and dynamic modulus values was examined, and empirical models were developed using statistical regression analysis techniques. Results revealed excellent correlative relationships among MOE values. Coefficients of determination obtained were 0.92, 0.96, and 0.93 for MOE of static transverse vibration, MOE of static longitudinal vibration, and MOE of longitudinal transverse vibration, respectively. Correlative relationships were also observed between NDE parameters and tensile strength. Coefficients of determination were similar to those observed for strength predication models developed for other species.

Nondestructive Evaluation of Southern Pine Lumber
Nondestructive Evaluation of Southern Pine Lumber

Author: Frederico Jose Nistal Franca

Publisher:

Published: 2017

Total Pages: 80

ISBN-13:

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Southern pine (SP) lumber is the primary softwood material in the United States. The main procedure during lumber grading process is the identification of the strength reducing characteristics that impacts the modulus of rupture (MOR). Non-destructive evaluation technology can be used to identify higher-stiffness material. This study investigated the use of vibration methods to evaluate the mechanical properties of southern pine lumber. Significant correlations between the properties determined by nondestructive techniques and the static MOE were found. No strong correlations were found for MOR because it is related to the ultimate strength of material, often associated with the existence of localized defects, such as a knot. Non-destructive measurements, visual characteristics, and lumber density were used as independent variables. Linear models were constructed to indirectly estimate the MOE and MOR. The variables selected was dynamic modulus of elasticity (dMOE) to predict MOE. Adding density and knot diameter ratio to the model it was possible to develop a prediction model for MOR. It was possible to improve predictability of strength (MOR) with a combination of non-destructive and knot evaluation.

Nondestructive Evaluation of Wood
Nondestructive Evaluation of Wood

Author: Forest Service (U S )

Publisher: Government Printing Office

Published: 2015

Total Pages: 176

ISBN-13: 9780160928871

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Nature's engineering of wood through genetics, wind, and weather creates a wide variability in wood as a material. Consequently, manufacture and users of wood products are frequently frustrated in dealing with the forest resource. Manufacturers sometimes argue that wood is difficult to consistently process into quality products because of the wide range of properties that exist in this raw material. Users of wood products can be equally frustrated with the performance variability found in finished products. Nondestructive evaluation (NDE) technologies have contributed significantly toward eliminating the cause of these frustrations. NDE technologies have been developed and are currently used in lumber and veneer grading programs that result in engineered materials that have consistent well-defined performance characteristics. This brief volume explores some of the processes that are used to manufacture wood, including green wood technology and provides a bit of history to wood production and its uses too. Other products that may interest you from the US Forest Service can be found at this link: https://bookstore.gpo.gov/agency/819

Tension Parallel-to-grain Properties of Southern Pine Dimension Lumber
Tension Parallel-to-grain Properties of Southern Pine Dimension Lumber

Author: D. V. Doyle

Publisher:

Published: 1967

Total Pages: 39

ISBN-13:

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Study provides an appraisal of tensile properties of present structural grades and sizes of southern pine 2-inch dimension lumber; provides a means of evaluating presently assigned working stresses; and includes pertinent data on appraisal of the possibilities and limitations of lumber grading based on a stiffness evaluation. (Author).