Research on wood gluing factors by a resonant oscillations method

This paper presents the methodology and equipment that is applied for experimental investigation of glued wood articles and their components by means of resonant vibrations. It is demonstrated that beam and plate, which form wood assortments along and across grain, may be studied by using theoretical calculations based on deformed beam vibrations. In addition, research data of oak glued-up panels of varying width as well as adhesive and scantlings are included. It was determined that the increase of width of the panels (the number of scantlings) practically does not change the shape of their first vibration mode. However, the research revealed slight changes in the amplitude-frequency characteristic, i.e., the first natural frequency increased up to 5 %, and the bandwidth decreased by 30 %. Irrespective of additional factors, the modulus of elasticity of the glued-up panels was higher by 10 % in comparison to average modulus of elasticity of the used scantlings, whereas damping coefficient was lower by 40 %. Obtained results may be used to evaluate the behavior of glued-up panels in the zone of dynamical loads and to produce glued-up panels with proper parameters