WOOD RESEARCH Volume 71, Number 3, 2026
Xingyu Shao, MING LI, SAIYIN FANG, TINGTING DENG, KUN DU, JINGGUI WANG, WENTAO XU, and HAO SHI

The Study on the Frequency Response Characteristics of Wood Orthotropy Based on Stress Wave Propagation Direction and Distance

This study investigates the frequency response of Zelkova schneideriana and Pinus sylvestris var. mongholica Litv. along longitudinal, radial, and tangential directions at different propagation distances. Sinusoidal signals from 20 to 200 kHz with 2 kHz intervals were applied using a piezoelectric device, and the responses were recorded by an acoustic emission sensor. Frequency response curves were obtained from the amplitude ratios of response to excitation signals. The results showed that attenuation in the radial direction was lower than that in the longitudinal and tangential directions between 20 and 100 kHz. Both species exhibited stable characteristic response bands around 35, 154, and 188 kHz, which showed good agreement with one-dimensional elastic wave theory, with a minimum relative error of 0.48%. Zelkova schneideriana also exhibited a characteristic frequency near 79 kHz and more stable high-frequency responses.

WOOD RESEARCH Volume 71, Number 1, 2026
KUN DU, LIJIAN YUAN, YOULI WANG, XINLIN LI, MING LI, SAIYING FANG, HAO SHI, YONGYOU CHEN, and XUANRUI GONG

DYNAMIC DETECTION THE DAMAGE AND FRACTURE PROCESS OF LOAD-BEARING WOOD USING ACOUSTIC EMISSION TECHNOLOGY

This research utilizes three-point bending experiment to simulate actual load-bearing scenarios of wood, and uses acoustic emission monitoring system to collect real-time acoustic emission signal parameters, such as ringing count, energy, amplitude, etc. Analyze the relationship between acoustic emission signals and internal damage during different loading stages, and construct an acoustic emission recognition model for damage and fracture process of elm. Research result shown that during elastic deformation and early plastic deformation stage, the activity of acoustic emission is weak, mainly due to damage and delamination at cell wall, and cell wall buckling and collapse. Entering plastic deformation stage, acoustic emission ringing count and energy significantly increase, corresponding to a large number of cell wall ruptures and microcrack initiation. Near macroscopic fracture stage, high-intensity and high-energy acoustic emission signal clusters appear, indicating rapid propagation of main crack and ultimately leading to fracture.