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.