Download or read book Stress Wave Techniques for Determining Quality of Dimensional Lumber from Switch Ties written by Kristin C. Schad and published by . This book was released on 1995 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Stress Wave Techniques for Determining Quality of Dimensional Lumber from Switch Ties written by Kristin C. Schad and published by . This book was released on 1995 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: Researchers at the Forest Products Laboratory, USDA Forest Service, have been studying nondestructive techniques for evaluating the strength of wood. This report describes the results of a pilot study on using these techniques to determine the quality of large dimensional lumber cut from switch ties. First, pulse echo and dynamic (transverse vibration) techniques were used to determine the modulus of elasticity (MOE) of 12 untreated red oak switch ties. The ties were then sawn into nominal 2 by 8 specimens, which were later resawn into nominal 2 by 4 specimens. Pulse echo and transverse vibration techniques were used to determine the MOE of the individual lumber members. Positive correlations were observed between the pulse echo MOE of a switch tie and the full-length parallel-tograin pulse echo MOE and dynamic MOE of the lumber sawn from the tie. The accuracy of the prediction of lumber MOE decreased with a reduction in the size of the members: the greater the number of members cut from the tie, the less accurate the prediction. Strong relationships were seen between pulse echo and dynamic MOE of both green and dry lumber. The data also demonstrate that the speed of sound can be useful in predicting internal degradation of a tie and can be correlated to the specific gravity of the tie. The latter finding may be useful to hardwood crosstie producers who have expressed interest in a simple species-independent technique for nondestructive grading of ties on the basis of density.
Download or read book Stress Wave Techniques for Deter omomg Quality of Dimensional Lumber from Switch Ties written by Kristin C. Schad and published by . This book was released on 1995 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Research Note FPL written by and published by . This book was released on 2006 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book U S Forest Service Research Note FPL written by and published by . This book was released on 1995 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book PRO 8 1st International RILEM Symposium on Timber Engineering written by Lars Boström and published by RILEM Publications. This book was released on 1999 with total page 872 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Resistance Moisture Meter Correction Factors for Four Tropical Wood Species written by William Turner Simpson and published by . This book was released on 1994 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Research Paper FPL RP written by and published by . This book was released on 1986 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dividends from Wood Research written by and published by . This book was released on 1995-07 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Several Nondestructive Evaluation Techniques for Assessing Stiffness and MOE of Small diameter Logs written by and published by . This book was released on 2001 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many forests of the United States have large areas that contain trees of small diameter, mixed species, and undefined quality. Because these areas are at risk from attack by insects, disease, and uncontrollable wild fires, it is essential to find ways to increase the incentive to harvest this small-diameter material. One way to do this is to develop cost-effective products for the fiber from these trees. Nondestructive technology needs to be developed to evaluate the potential quality of stems and logs obtained from trees in such ecosystems. Static bending, transverse vibration, and longitudinal stress wave techniques are frequently used to assess the modulus of elasticity (MOE) of lumber. Excellent correlations between MOE values obtained from these techniques have been reported. The objective of this study was to investigate the use of these techniques to evaluate the flexural stiffness and MOE of small-diameter logs. A total of 159 red pine and jack pine logs were obtained from northern Michigan and were assessed nondestructively using these techniques. Statistical comparisons between stiffness and MOE values obtained from each technique were then examined. Results of this study demonstrated that strong relationships exist between the log properties determined by the three techniques, longitudinal stress wave, transverse vibration, and static bending. Developed models allow for the prediction of static bending properties of logs at levels of accuracy previously considered unattainable. This indicates that any of these techniques can be used to sort small diameter logs with reasonable accuracy.
Download or read book Cantilever beam Dynamic Modulus for Wood Composite Products written by Chris Turk and published by . This book was released on 2008 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: A cantilever-beam vibration-testing apparatus has been developed to provide a means of dynamic and non- destructive evaluation of modulus of elasticity for small samples of wood or wood-composite material. The apparatus applies a known displacement to a cantilever beam and then releases the beam into its natural first-mode vibration and records displacement as a function of time. That frequency and amplitude attenuation is then used to calculate the dynamic material properties of the cantilever beam. The dynamic testing is quick and calculates the dynamic modulus and loss-tangent damping coefficient.
Download or read book National Conference on Wood Transportation Structures written by and published by . This book was released on 1996 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Research Note FPL RN written by and published by . This book was released on 1986 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Role of Wood Production in Ecosystem Management written by International Union of Forestry Research Organizations. Sustainable Forestry Working Group and published by . This book was released on 1997 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book General Technical Report FPL written by and published by . This book was released on 1978 with total page 784 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Wood and Fiber Science written by and published by . This book was released on 1983 with total page 696 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Undervalued Hardwoods for Engineered Materials and Components written by Eugene Lee Bryan and published by . This book was released on 2005 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:
