Natureas engineering of wood through genetics, stand conditions, and environment creates wide variability in wood as a material, which in turn introduces difficulties in wood processing and utilization. Manufacturers sometimes find it difficult to consistently process wood into quality products…
Keywords: Picea sitchensis, Tsuga heterophylla, forest trees, nondestructive testing, wood strength, strength testing, stress analysis, silvicultural systems, forestry practices, stiffness
Source: (Research paper FPL ; RP-585):9 p. : ill. ; 28 cm.
Bridges require periodic inspections to ensure the safety of those using the structure. A visual inspection has historically been the most common form of investigation for timber bridges. This poses many problems when inspecting bridge timbers since often the damage is internal, leaving no visible…
Keywords: Timber bridges, nondestructive testing, impact generated FRFs, frequency response functions
Source: Proceedings of the 20th International Modal Analysis Conference. Bethel, Conn. : Society for Experimental Mechanics, 2002: Pages 1567-1573
Existing log grading procedures in the United States make only visual assessments of log quality. These procedures do not incorporate estimates of the modulus of elasticity (MOE) of logs. It is questionable whether the visual grading procedures currently used for logs adequately assess the…
Keywords: Red maple, log grading, nondestructive testing
Source: Hardwood Symposium proceedings : May 11-13, 2000, Davis, WV. Memphis, TN : National Hardwood Lumber Association, 2000: Pages 95-101
This paper presents some research results from recent trial studies on measuring acoustic velocities on standing trees of five softwood species. The relationships between tree velocities measured by time of flight method and log velocities measured by resonance method were evaluated. Theoretical…
Keywords: Trees, nondestructive testing, wood, grading, mechanical properties, softwoods, wood quality, acoustic testing, standing trees, acoustic velocity
Source: Proceedings of the 14th International Symposium on Nondestructive Testing of Wood : May 2-4, 2005, University of Applied Sceinces, Eberswalde, Germany. Aachen, Germany : Shaker Verlag, 2005: ISBN 3832239499: pages 455-465
This poster presentation reports on recent laboratory work aimed at quantifying the biodegradation process of wood during exposure to natural weathering. Approximately 330 southern pine lumber specimens were placed “above-ground” at an outdoor exposure site near Gulfport, Mississippi for periods up…
Keywords: Wood preservatives, multivariate analysis, near infrared spectroscopy, nondestructive testing, spectrum analysis, deterioration, weathering, preservatives, DDAC, Didecyl-dimethyl ammonium chloride, treated wood, chromated copper arsenate, CCA, durability, southern pine, wood decay, exposure tests
Source: WCTE 2006 : 9th World Conference on Timber Engineering, August 6-10, 2006, Portland, OR, USA : program and abstracts. Portland, Or. : World Conference on Timber Engineering, :  pages.
The Federal Highway Administration (FHWA) set up a validation test to compare the effectiveness of various nondestructive inspection techniques for detecting artificial defects in glulam members. The validation test consisted of a glulam beam fabricated with artificial defects known to FHWA…
Keywords: Inspection, timbers, wood defects, ultrasonic waves, laminated wood, ultrasonics, nondestructive testing, voltage, glulam
Source: Proceedings of the 90th Annual Meeting of the Transportation Research Board : Jan. 7-11, 2001. [S.l. : s.n.], 2001: pages 1-19.
This paper describes an effort to refine a global dynamic testing technique for evaluating the overall stiffness of timber bridge superstructures. A forced vibration method was used to measure the frequency response of several simple-span, sawn timber beam (with plank deck) bridges located in St.…
Keywords: Dynamic testing, service life, wood deterioration, deterioration, nondestructive testing, vibration, wooden bridges, inspection, bridges, frequency response, bending strength, simple beam theory, bending mode frequency, stiffness, timber bridges
Source: Proceedings : NDE Conference on Civil Engineering : a joint conference of the 7th Structural Materials Technology: NDE/NDT for Highways and Bridges and the 6th International Symposium on NDT in Civil Engineering, 2006 August 14-18, St. Louis, MO. Columbus, OH : American Society for Nondestructive Testing, Inc., 2006: ISBN: 1571171487: pages 63-70.
A timber bridge consisting of three 6.7 meter spans with a stress laminated deck was constructed in 1991 in the Spirit Creek State Forest near August, Georgia, USA. The stress laminated bridge uses a series of post-tensioning bars to hold the laminations together. The bridge remained in service…
Keywords: Laminated wood, bridges, floors, nondestructive testing, dead loads, testing, inspection, wooden bridges, moisture, glulam timbers, static loads, laminated bridges, stress-laminated bridges, timber bridges
Source: Proceedings of the 7th International Conference on Short and Medium Span Bridges 2006, 2006 August 23-25, Montreal, Quebec, Canada. Montreal, Quebec, Canada : Canadian Society for Civil Engineering: pages RE-012-1--RE-012-10.
This report summarizes the main points considered and the conclusions reached during the Symposium on Nondestructive Testing, October 7 to 9, 1963, at the Forest Products Laboratory. The purpose of this symposium was to bring research and industry leaders together to examine what is being done in…
Keywords: Industry, wood products, nuclear radiation, vibration, forest products, nuclear magnetic resonance, spectroscopy, hydrogen, moisture content, nondestructive testing, sonic devices, electrical devices, NMR, internal friction, speed of sound
Source: Res. note FPL-40. Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory: 56 pages.
Ultrasonics, the technology of high-frequency sound, has been developed as a viable means for locating most defects In lumber for use in digital form in decision-making computers. Ultrasonics has the potential for locating surface and internal defects in lumber of all species, green or dry, and…
Keywords: Computers, ultrasonics, decision making, moisture content, species, surfaces, nondestructive testing, scanning, lumber, planing, processing, rough sawn, sanded, defect detection, wood decay
Source: Res. Paper FPL-311. Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory: 21 pages.