An overview on the mechanical and physical properties of cross laminated timber (solid wood
panels) in the building industry and its use in timber construction is presented. Structure-property
relations for solid wood based materials are discussed. Important properties, such as strength, sorption, diffusion, thermal conductivity in relation to the board structure are presented. By varying the structure, the properties can be optimized over a wide range. The focus of this publication lies on experimental works performed by Swiss researchers at the ETH Zürich.
Structural Health Assessment of Timber Structures 15
September 9-11, 2015, Wroclaw, Poland
The paper presents the application of ultrasonic and stress wave techniques in testing the physical and mechanical properties of timber. One of the non-destructive methods for testing timber in construction involves measuring the velocity of ultrasonic and stress wave propagation. The research was carried out using a portable Sylvatest Trio device, which uses ultrasonic technology and a Fakopp Microsecond Timer device, which employs the stress wave technique. The devices measure the wave transition time along a given length of the material, providing qualitative (the extent of possible degradation, structural discontinuities etc.) and quantitative results (density, strength, modulus of elasticity) relating to the state of the timber under study. The paper reports on research on the correlation between wood properties and parameters of ultrasonic and stress wave propagation. The study focused on glued laminated spruce wood of strength class GL24h. Testing involved application of two methods of setting up transducers: directly where the device heads are located on the opposite planes of the test specimens, and where the device heads are located in parallel to or perpendicular to the grain.
Annals of Warsaw University of Life Sciences - SGGW
Non-destructive testing of wood – correlation of ultrasonic and stress wave test results in glued laminated timber members. The paper presents application of selected non-destructive testing techniques – ultrasonic and stress wave methods - for assessment of the physical and mechanical properties of wood. Nondestructive testing is a scientific field related to: identification of mechanical properties and physical parameters of materials and structural members, detecting material defects and discontinuities, measurement of geometrical dimensions without affecting the functional properties of the elements under investigation. The paper provides a short description of selected methods used for non-destructive and quasi non-destructive testing of wood. It also reports on research on the correlation between glued laminated spruce wood properties and parameters of ultrasonic and stress wave propagation The research was carried out with a Sylvatest Trio device, which uses ultrasonic technology and a Fakopp Microsecond Timer device, which uses the stress wave technique.
Palm trees are a family of plants with hundreds of species. Most important species are coconut palm, oil palm and date palm. Most palms grow in tropical regions, but some species also in semidry regions (date palms). Palms have played an important role for the supply of food and they provide shade for agricultural crops and they are planted in parks and gardens. With exception for coconut wood, the wood from palm trees has not been used to a large extent. But it is considered as an important resource. According to FAO, coco-, oil- and date palms cover over 30 million ha worldwide with a total stem wood potential of 150-200 million m³ per year. Generally this wood resource can play an important role in the regional/worldwide wood supply; mainly in Asia, Arabic countries, Africa and Latin America. The stem of the tree (coconut-, oil- and date Palm) is between 10 and 20 (25) m long, has a lower diameter of 40 – 60 cm and a taper of 0.3 – 0.7 cm/m. Being monocotyledons, palms show distinct differences in the wood structure compared to common wood species.
Summarizes information on wood as an engineering material. Presents properties of wood and wood-based products of particular concern to the architect and engineer. Includes discussion of designing with wood and wood-based products along with some pertinent uses. Keywords: wood structure, physical properties (wood), mechanical properties (wood), lumber, wood-based composites, plywood, panel products, design, fastenings, wood moisture, drying, gluing, fire resistance, finishing, decay, preservation, wood-based products, heat sterilization, sustainable use.