Download or read book Strength and Stiffness of Small Glued laminated Beams with Different Qualities of Tension Laminations written by Catherine M. Marx and published by . This book was released on 1981 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Strength and Stiffness of Small Glued laminated Beams with Different Qualities of Tension Laminations written by Catherine M. Marx and published by . This book was released on 1981 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this research study was twofold: (a) to determine at what beam depth specially graded 302-24 (2) tension laminations are required to attain a 2,400 lb/sq. in. design stress; (b) to determine the appropriate design stress for specification-type beams with the regular laminating grades of L1 Douglas Fir-Larch (DF-L) or No. 1D Southern Pine (SP) as the tension laminations. The 302-24 grade of lumber required for tension laminations on 24F4 deep beams is a limited resource and is not as readily available as L1 or No. 1D lumber now used as the tension lamination on 24F shallow beams-thus necessitating objective (b). The 180 glued-laminated beams evaluated were of near-minimum quality; each selected tension lamination had a near-maximum-size, strength-reducing characteristics positioned in the most highly stressed region of the test beams. (Author).
Download or read book Strength and Stiffness of Reinforced Yellow poplar Glued laminated Beams written by and published by . This book was released on 1997 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: In bridge applications, it is often necessary to minimize the depth of the bridge structure to provide for the required hydraulic opening or reduce the volume of approach fill. For bridges that utilize structural glued-laminated (glulam) timber beams as stringers, reinforcement using thin strips of pultruded E-glass-fiber-reinforced plastic (GFRP) composites may permit reduced depth, because the reinforcement has the potential to increase stiffness and strength. This study is part of an overall effort aimed at evaluating the potential for commercial production of glulam-GFRP beams in current wood laminating plants and a wood adhesive compatible with existing equipment. Twelve Yellow-Poplar glulam GFRP beams were commercially manufactured, and their performance was evaluated. The GFRP panels were bonded to the wood with a resorcinol formaldehyde adhesive to provide the reinforcement. The simplicity of the process used to manufacture the test beams indicates that the commercial production of glulam-GFRP beams is feasible. Increases of 18 percent in stiffness and 26 percent in strength were achieved by adding 3 percent of GFRP by volume. The bending strength values of the beams predicted by the ASTM D3737 procedure correlate well with the experimental values. However, the observed delamination of the reinforcement indicates that improved bonding strength of wood--GFRP interfaces is needed. Results of this study will be useful to manufacturers interested in improving the performance of glulam timber beams.
Download or read book Strength Validation and Fire Endurance of Glued laminated Timber Beams written by Erwin L. Schaffer and published by . This book was released on 1986 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: A previous paper presented a reliability-based model to predict the strength of glued-laminated timber beams at both room temperature and during fire exposure. This Monte Carlo simulation procedure generates strength and fire endurance (time-to-failure, TTF) data for glued-laminated beams that allow assessment of mean strength and TTF as well as their variability. This paper reports an effort to validate model predictive capability through an independently fabricated set of 21 glued-laminated beams. Based upon the available data for the model input parameters on lumber strength and stiffness, finger-joint strength, and length of laminating lumber between sequential finger joints, the model of beam strength appears acceptable and possibly slightly conservative. Refinements in the beam strength model allow its use for predicting fire endurance. In this case, the fire endurance is measured by the TTF and is defined as the time the beam will support its design load while subjected to fire. The residual strength of the beam is analytically calculated by removing the char layer, plus a finite thickness of weakened wood, from the beam cross section as fire exposure time increases. Employing the input parameters for values of finger-joint strength and lamination grades of Douglas-fir, the fire endurance TTF was analyzed for a 5.12- by 16.50-inch 11-lamination Douglas Fir-Larch beam (24F-V4) carrying full allowable uniform load (47.7 lb/in.). (Three-sided fire exposure was assumed; however, four-sided exposure can also be accommodated.) A simulated random fabrication and analysis of the TTF under fire exposure for 100 beams was performed. The mean TTF was estimated as 35.2 minutes with a coefficient of variation of 13.7 percent. Lateral torsional buckling was never the cause of failure in any of the simulations. The results compared well (within a 65 pct confidence band) with the observations and predictions for timber beams reported by sources in other countries. A simulation for a single glulam beam test in cooperation with the National Forest Products Association was also conducted which predicted the result exactly.
Download or read book Large Glued laminated Timber Beams with Two Grades of Tension Laminations written by Billy Bohannan and published by . This book was released on 1969 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Flexural Properties of Glued laminated Southern Pine Beams with Laminations Positioned by Visual stiffness Criteria written by Russell Charles Moody and published by . This book was released on 1970 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Improved Utilization of Lumber in Glued Laminated Beams written by Russell Charles Moody and published by . This book was released on 1977 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Reliability Formulation for the Strength and Fire Endurance of Glued laminated Beams written by and published by . This book was released on 1985 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: A model was developed for predicting the statistical distribution of glued-laminated beam strength and stiffness under normal temperature conditions using available long span modulus of elasticity data, end joint tension test data, and tensile strength data for laminating-grade lumber. The beam strength model predictions compared favorably with test data for glued-laminated beam strength data with 8 and 10 laminations; however, the model predicted strength values 30 percent higher for glued-laminated beam strength data with 4 laminations. Fire endurance and structural resistance were evaluated by artificially reducing the cross section. This reduction accounts for char depth as well as for reduced wood strength caused by the elevated temperature. Average time-to-failure predictions using the developed model compared well with those from conventional prediction methods.
Download or read book Design criteria for large structural glued laminated timber beams using mixed species of visually graded lumber written by Russell Charles Moody and published by . This book was released on 1974 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bending Strength of Water soaked Glued Laminated Beams written by Ronald W. Wolfe and published by . This book was released on 1978 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Flexural Properties of Glued laminated Southern Pine Beams written by Russell Charles Moody and published by . This book was released on 1971 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the continuing reappraisal of design criteria for glued-laminated timbers, five large beams with finger joints at midlength of the tension lamination were destructively evaluated. Results indicate finger joints of acceptable strength for tension laminations can be produced if wood quality is controlled and adequate quality control procedures followed. (Author).
Download or read book Fiber Stress Values for Design of Glulam Timber Utility Structures written by Roland Hernandez and published by . This book was released on 1995 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Flexural Properties of Glued laminated Southern Pine Beams with Laminations Positioned by Visual stiffness Criteria written by Russell Charles Moody and published by . This book was released on 1970 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: To establish the effect of using modulus of elasticity in addition to visual grades as criteria for the positioning of laminations in glued-laminated beams, an experimental study on southern pine members was conducted. The beams were manufactured in accordance with current specifications for glued-laminated southern pine timber, except that (a) minimum-quality tension laminations meeting AITC 301-67 were used and (b) restrictions were placed on the modulus of elasticity of all laminations. The average modulus of elasticity of the beams manufactured using both visual and stiffness criteria was 12 percent higher than that for beams using only the visual criteria. This agreed with the theoretically expected increase in modulus of elasticity. The average modulus of rupture of the visual-stiffness beams was 14 percent higher than that for the visual-only beams. However, the minimum strength for each group was approximately equal. (Author).
Download or read book Improved Performance of Southern Pine Structural Glued laminated Timber written by Roland Hernandez and published by . This book was released on 1992 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Performance of Red Maple Glulam Timber Beams written by Harvey Bright Manbeck and published by . This book was released on 1993 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Large Glued laminated Timber Beams with Two Grades of Tension Laminations written by Billy Bohannan and published by . This book was released on 1969 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bending strength of 26 glued-laminated timbers were appraised as a basis for more precise design. Part of the beams were manufactured according to present AITC and lumber industry specifications, while the other beams had improved tension laminations. When tested to failure, 11 beams failed at end joints and 15 in the wood. (Author).
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1982 with total page 1282 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
