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Book The Influence of Moisture Content on the Flexural Properties of Southern Pine Dimension Lumber

Download or read book The Influence of Moisture Content on the Flexural Properties of Southern Pine Dimension Lumber written by and published by . This book was released on 1984 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: Based on the study results we conclude that: (1) In general, drying increases the flexural properties of Southern Pine dimension lumber. (2) Improvements in Moduli of Rupture (MOR) and Moduli of Elasticity (MOE) with drying are significant for Select Structural lumber at virtually all levels of the cumulative frequency distribution. The magnitude of the increase for mean MOE and fifth percentile MOR for Select Structural lumber appears to exceed that assumed in ASTM standard D245-81 for lumber dried to an equilibrium Moisture Content (MC) of 15%. (3) The degree of improvement in strength as lumber dries decreases as lumber quality decreases and width increases. For lower grades and wider widths, the 25% increase in fifth percentile MOR assumed in D245-81 appears excessive. (4) The effect of MC on MOE is relatively independent of lumber size and quality. (5) Drying lumber to an average MC less than 15% cannot usually be justified on the basis of improvements in flexural strength and stiffness.

Book Strength Moisture Content Relationships for Southern Pine Structural Lumber

Download or read book Strength Moisture Content Relationships for Southern Pine Structural Lumber written by A. Louis DeBonis and published by . This book was released on 1980 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effect of moisture content on the strength and stiffness of southern pine dimension lumber is being investigated. Three visual grades (Select Structural, No. 2 and No. 3) and three sizes (2x4, 2x6 and 2x8) are being conditioned to four target moisture content conditions (10%, 15%, 20% and green). The lumber is being non-destructively evaluated in a flatwise orientation for determination of Modulus of Elasticity (MOE) and is then tested to failure in edgewise bending to evaluate MOE and Modulus of Rupture (MOR). It is anticipated that the relationships found will be used for the development of an analytical model describing the effect of moisture content on the strength and stiffness of visually-graded southern pine dimension lumber. (Author).

Book Computer Programs for Adjusting the Mechanical Properties of 2 inch Dimension Lumber for Changes in Moisture Content

Download or read book Computer Programs for Adjusting the Mechanical Properties of 2 inch Dimension Lumber for Changes in Moisture Content written by James William Evans and published by . This book was released on 1990 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book The Effect of Moisture Content on the Tensile Strength of Southern Pine Lumber

Download or read book The Effect of Moisture Content on the Tensile Strength of Southern Pine Lumber written by Bambang Suryoatmono and published by . This book was released on 1994 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Research Paper FPL

Download or read book Research Paper FPL written by and published by . This book was released on 1985 with total page 682 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Long term Load Performance of Hardboard I beams

Download or read book Long term Load Performance of Hardboard I beams written by J. Dobbin McNatt and published by . This book was released on 1983 with total page 688 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Characterizing the Effect of Moisture Content on the Flexural Properties of Sugar Pine and Black Spruce Dimension Lumber

Download or read book Characterizing the Effect of Moisture Content on the Flexural Properties of Sugar Pine and Black Spruce Dimension Lumber written by James J. Vogt and published by . This book was released on 1988 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Current Topics in Forest Research

Download or read book Current Topics in Forest Research written by and published by . This book was released on 1987 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thirty-four papers are presented in nine categories: silviculture/ecology, genetics, soils and nutrients, regeneration, forest products, sociology, economics, policy, and insects and diseases. Also included is the keynote address, "Women in natural resources," by R. Max Peterson

Book Wood Water Relations

Download or read book Wood Water Relations written by Christen Skaar and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wood is formed in an essentially water-saturated environment in the living tree, and the cell wall remains in this state until the water flow from the roots is interrupted, such as by felling the tree. The wood then begins to lose most of its moisture by drying, resulting in changes in most of its physical properties. These changes, and their relationship to the environment to which the wood is subsequently ex posed, are the subject of this book. The text consists of six chapters. The first chapter discusses cer tain empirical relationships between wood and water, methods of measuring wood moisture content, factors which affect its equilib rium moisture content, and the effect of moisture content on wood strength. The second chapter treats the thermodynamics of moisture sorption by wood, inc1uding enthalpy, entropy, and free energy changes. The third chapter discusses some of the theories which have been proposed to explain the sorption isotherms for hygroscopic ma terials such as wood. Chapter 4 considers hygroexpansion or the shrinking and swelling of wood associated with moisture change. Chapter 5 is concerned with how moisture moves through the cell wall of wood in response to both moisture and temperature gradients. The sixth and final chapter discusses the theoretical and practical aspects of the electrical resistance and dielectric properties of wood, in c1uding the principles involved in their application in electrical moisture meters.

Book Confidence Intervals for Predicting Lumber Strength Properties Based on Ratios of Percentiles from Two Weibull Populations

Download or read book Confidence Intervals for Predicting Lumber Strength Properties Based on Ratios of Percentiles from Two Weibull Populations written by Richard Arnold Johnson and published by . This book was released on 2003 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ratios of strength properties of lumber are commonly used to calculate property values for standards. Although originally proposed in terms of means, ratios are being applied without regard to position in the distribution. It is now known that lumber strength properties are generally not normally distributed. Therefore, nonparametric methods are often used to derive property values. In some situations, estimating properties based on a parametric estimate is required. For these situations, the three-parameter Weibull distribution looks promising. To use this approach, procedures for estimating confidence intervals for ratios of percentiles from two Weibull populations are needed. In this study, we employed the large sample properties of maximum likelihood estimators to obtain a confidence interval for the ratio of 100Sa-th percentiles from two different three-parameter Weibull distributions. The coverage probabilities were investigated by a computer simulation study. We concluded that the procedure has considerable promise, but many questions remain to be answered.