The LTC, supplemented by a fully equipped wood workshop for the production and processing of test specimens, has the following laboratory equipment:
The universal testing machine lignum_uni_275 (Z-250, Zwick GmbH & Co. KG) enables the accomplishment of various standard test procedures as well as those with special requirements within a load range of 0 kN to ± 275 kN. Specimen width is limited to 1,000mm.
The tensile testing machine lignum_z_850 (GEZU 850, ZUM WALD) enables the accomplishment of static tensile tests of rectangular shaped specimens within a load range of 0 kN to +850 kN. The free span length ranges between 1,450 mm and 6,000 mm.
The tensile/compressive testing machine lignum_dz_1000 enables the accomplishment of static and dynamic tests of rectangular shaped specimens within a load range of -800 kN to +1,100 kN. The free span length is continuously adjustable between 50 mm and 6,000 mm.
The torsional testing machine (owned by the TVFA), originally developed for torsional tests on screws, makes it possible to carry out torsional tests of rod-shaped members up to a maximum torque of 5 kNm.
The testing equipment developed by the LTC is used to determine the yield moment of dowel-type fasteners according to EN 409.
The dynamic modulus of elasticity is an appropriate indicator for the prediction of individual mechanical properties of wood and commonly applied as (stiffness) grading criterion. The dynamic modulus of elasticity is determined with the ultrasonic runtime and the density of the test specimen. The ultrasonic runtime is determined by measuring the time of an ultrasonic wave in the wood between two transducers. The measurement can be accomplished for single supported test specimens as well as for stacked specimens. This ensures an easy and fast determination.
The extended natural frequency measurement device works by excitation of a rod-shaped timber specimen and measurement of the arising longitudinal oscillation. The natural frequency is determined by FFT analysis and used for calculating the stress-wave speed. In contrast to common natural frequency measurement devices, the excitation apart of the oscillation response is additionally recorded. The dynamic modulus of elasticity is determined by considering the timber density. The natural frequency measurement is especially suitable for determining the dynamic properties of timber in green condition.
The Hydromette is an electronic wood moisture and temperature measurement device with the option of storing data locally and on a computer-interface. Wood moisture contents between 8 % and 28 % are determined exactly. Measurements of air and material temperatures are possible as well.
The drilling resistance instrument determines the drilling resistance of wood on site by recording measured data on strips of wax paper strips. The main application is the inspection of timber constructions (and tree care), additionally conducted to a visual inspection. The device is powered by a battery-operated drilling machine and thus suitable for almost all operating conditions. Measurement at angles deviating from 90° can be carried out by an attachable adapter.
The drying cabinet of Heraeus is used for the determination of the moisture content by means of the oven-dry method. The device works with natural convection in a temperature area up to 250°C.
The LTC has two climatic chambers with a total volume of 150 m³. The parameters temperature (10°C-30°C) and relative humidity (30 %-95 %) can be set individually for each chamber.
Institute of Timber Engineering and Wood TechnologyGraz University of TechnologyInffeldgasse 24A-8010 Graz
Tel.: +43 (0)316 873 - 4601Fax: +43 (0)316 873 - 4619lignumnoSpam@tugraz.at