南京林业大学学报（自然科学版）2017，Vol.41Issue(3)：133-139,7.DOI:10.3969/j.issn.1000-2006.201609032
应力波在落叶松活立木中的传播规律
Stress wave propagation patterns in larch standing trees
摘要
Abstract
[Objective] The primary purpose of this study was to explore the propagation patterns of stress waves traveling in larch standing trees,and pave a theoretical foundation for further study on the prediction and evaluation of the mechanical properties of these plantation trees.[Method] In this study,the wave fronts of stress waves propagating in standing trees were simulated,and the forms of two-dimensional and three-dimensional propagation patterns of the stress waves propagating in standing trees were studied by using COMSOL Multiphysics finite element analysis software,based on the stress wave propagation theory in a solid medium and the orthotropic assumption for standing trees.Finally,a field experiment for the measurement of stress-wave timing was conducted to verify the validity of the numerical simulation method.[Result] It was found that the wavefront at the starting stage was a sloping curve or surface,bending to input point of force pulse and with the increase in distance,the inclination of the wavefront decreased gradually until it was approximately vertical to the length direction,i.e.,the wavefront gradually changed from a 3D wave to a quasi-plane wave.The rate of decrease of the wavefront inclination increased with decreasing tree diameter.The travel distance had no effect on the wave velocity,but the wave velocity generally increased with increasing diameter.Finally,the feasibility of the simulation method used for investigating the stress-wave propagation pattems in standing trees was verified.[Conclusion] The numerical simulation method is practicable for the study of the propagation patterns of stress waves in standing trees and the effects of the diameter and propagation distance on the wave velocity.The diameter as well as the propagation distance could influence the propagation patterns of stress waves in standing trees,but their effects on stress-wave velocity were different.关键词
应力波/落叶松活立木/COMSOL Multiphyscis/数值模拟/正交各向异性Key words
stress wave/larch standing trees/COMSOL Multiphysics/numerical simulation/orthotropy分类
农业科技引用本文复制引用
刘丰禄,姜芳,王喜平,张厚江,刘兴凯..应力波在落叶松活立木中的传播规律[J].南京林业大学学报（自然科学版）,2017,41(3):133-139,7.基金项目
国家自然科学基金项目(31328005) （31328005）
