Acoustic emission attenuation and source location on the bending failure of the rectangular mortise-tenon joint for wood structures

Since the mortise-tenon joints of wood structures are hidden members, the fracture location of the mortise-tenon joints could not be tested accurately by naked eyes. In order to predict accurately the health condition of the mortise-tenon joints, acoustic emission information location could be detected according to the propagation properties of acoustic emission energy released by wood before the mortise-tenon joints fracture. Energy attenuation law of the acoustic emission signal for wood was verified in this paper, and a new method was proposed to locate the damage of mortise-tenon joints based on energy attenuation model for wood. Firstly, using 0.5 mm diameter pencil lead as artificial acoustic emission source, acoustic emission wave propagation and attenuation characteristics were discussed for wood. And then the bending failure experiments of the mortise-tenon joints were studied. In the process of the experiments, acoustic emission source was located between the two sensors, and two-point positioning method was used to determine the fracture location of the mortise-tenon joints. The calculation values of the fracture location agreed with the experimental ones. The results show that the positioning method could acquire accurate fracture location based on energy attenuation model of the AE signal and two-point method, and the results are less affected by the external environment.