文献类型：期刊文献

英文题名：ACOUSTIC WAVE PROPAGATION IN STANDING TREES-PART I. NUMERICAL SIMULATION

作者：Liu, Fenglu[1] Wang, Xiping[2] Zhang, Houjiang[1] Jiang, Fang[1] Yu, Wenhua[1] Liang, Shanqing[3] Fu, Feng[3] Ross, Robert J.[2]

第一作者：Liu, Fenglu

通信作者：Wang, XP[1]

机构：[1]Beijing Forestry Univ, Sch Technol, Beijing, Peoples R China;[2]US Forest Serv, USDA, Forest Prod Lab, Madison, WI 53726 USA;[3]Chinese Acad Forestry, Res Inst Wood Ind, Beijing, Peoples R China

年份：2020

卷号：52

期号：1

起止页码：53-72

外文期刊名：WOOD AND FIBER SCIENCE

收录：;EI(收录号：20201608414107);Scopus(收录号：2-s2.0-85083028239);WOS:【SCI-EXPANDED(收录号:WOS:000529410400004)】；

基金：This project was conducted through the research cooperation between Beijing Forestry University and the USDA Forest Service Forest Products Laboratory (11-MU-11111133-031; 18-LI-11111133-024) and was partially funded by the National Natural Science Foundation of China (grant no. 31328005). Financial support to Mr. Fenglu Liu's visiting study in the United States was provided by the China Scholarship Council.

语种：英文

外文关键词：Acoustic waves; boundary condition; COMSOL Multiphysics software; impulse load; orthotropic material; wave front; trees

摘要：The use of acoustic waves for assessing wood properties in standing trees has been investigated extensively in recent years. Most studies were experimental in nature and limited to direct measurement of wave velocities in trees using a time-of-flight (TOF) method. How acoustic waves propagate in a tree trunk and how tree diameter, species, stand age, and juvenile wood affect wave propagation behavior in standing trees are not well understood. In this study, we examined propagation patterns of acoustic waves in a virtual tree trunk through numerical simulation using COMSOL Multiphysics (R) software (COMSOL, Inc., Burlington, MA). The simulation was based on the elastic theory of a solid medium with the assumption of an orthotropic material for a standing tree. Extensive acoustic measurements were conducted on green larch log samples to validate the simulation results. Our results showed that the wave front maps of the tree model from numerical simulations were consistent with those obtained through TOF measurements on the log samples, indicating that the simulation results were accurate and reliable. Wave propagation patterns of the tree model revealed that the side surface-generated acoustic wave expanded as a dilatational wave within a 0- to 1.2-m transit distance; as the wave moved up along the tree model, the shape of the wave front gradually flattened and the wave eventually transformed into a quasi-plane wave from a 2.4-m transit distance.