The Analysis Of Precision And The Research Of Stress Wave Propagation Velocity Law In The Process Of Wood Nondestructive Testing

With the highly development of technology in today, stress wave wood nondestructive testing technology has been widely used in the timber and forestry and other related fields. Now there are a variety of mature stress wave wood nondestructive testing instruments in China and other countries. However, these stress wave wood nondestructive testing instruments have some common problems, such as that small cracks are always judged inaccurately, and a small area of rot is often reported by the smaller holes and mild rot timber cannot be detected. To solve these problems, the paper investigated the reasons of these problems through a series of experimental studies. In the paper, we analyzed the propagation speed of the stress wave difference in the healthy part of the timber and in the defective part of the timber. The effect causing by moisture or tangential angle on the stress wave propagation velocity in logs has been analyzed. In the end, the paper summarized the effect to stress wave propagation velocity caused by moisture and tangential angle together. In the end, a three-dimensional figure is fitted. These results provide theoretical support for the detection accuracy of stress wave nondestructive testing instrument and in-depth study of stress wave propagation in a timber.