ABSTRACT
Damage is a common occurrence in ancient wooden structures, and its impact on the mechanical properties of the structures cannot be ignored. A stress wave is a typical method to detect the internal damage to wood, and the needle-type sensor is usually used, which will cause slight damage to the outer surface of the wood. The protection of ancient wooden structures needs strict requirements, and the use of stickup sensors can avoid micro damage on the outer surface of wooden components, which is more appropriate from this perspective. In this paper, 17 different wood damage detection states are designed with the shape, area, location, and type of the damaged area and the number of measuring points as the running parameters. Based on the stickup sensors, a stress wave detector (FAKOPP 3D Acoustic Tomograph) is used for testing, and Arbor Sonic 3D produced by FAKOPP is used for graphic processing. The testing results show that the data gotten by the stickup sensors can obtain the stress wave detection images showing the hollows and the decayed areas. The stress wave detection image cannot effectively distinguish the shape of the damaged area, but can roughly display its position. The uneven side surface and the wood shrinkage crack impact the stress wave detection images to a certain extent. The test damage degree is higher than the actual damage degree on average, and the test damage degree deviation of the specimen with the damage type of hollow is larger. The increase in the number of measuring points can make the shape of the damaged area in the stress wave detection image and the test damage degree closer to the actual situation.
