Experimental Study on Ultrasonic Wave Velocity and Compression Performance of Small Glued Bamboo Specimens

As a deep processing product of bamboo, the glued bamboo material has the characteristics of high strength, uniform performance, good suitability for industrial production and processing. In order to study the mechanical properties of the glued bamboo materials, seven groups of 70 small glued bamboo specimens with different stacking directions and lengths were tested by ultrasonic wave velocity and axial compressive strength. The results showed that the glued bamboo material had high strength, and the main failure mode was the substrate failure rather than the delamination. The lamination direction of the glued substrate had a great influence on the ultrasonic velocity, stiffness and axial compressive strength, and the ultrasonic velocity was correlated with the strength and elastic modulus to a certain degree. Therefore, the strength and elastic modulus of the glued bamboo specimen can be non-destructively tested based on the ultrasonic wave velocity index. According to the compressive strength curve of each specimen, it can be found that the strength of the parallel compression specimen is significantly higher than that of the two other types of transverse compression specimens, the latter can still produce strength improvement in the later stage of the test, and the three types of specimens have greater plastic deformation capacity, and the different mechanical properties of the three types of specimens can make them be used in different scenarios.