%0 Journal Article
%T 自由板扭转振形法测定木材剪切模量
%A 王正
%A 王刚刚
%A 王韵璐
%A 曹瑜
%A 高子震
%J 林业工程学报
%D 2016
%R 10.13360/j.issn.2096-1359.2016.04.002
%X 在木材加工行业中,锯材是木结构建筑、家具、木地板等产品的主材,研究其刚度力学性能十分重要。为探讨与完善自由板扭转振形法动态测定木材3个剪切模量的原理和方法,应用自由板一阶扭转振形和能量法,导出了木材剪切模量与自由板一阶扭转频率的关系式,并给出木材弦切面、径切面和横切面振形系数依赖于自由板宽长比和厚宽比的公式。木材的弦切面、径切面和横切面振形系数可以通过公式计算,也可以通过查表获得。通过多树种的仿真计算和动静态试验验证了自由板扭转振形法测定木材弦切面、径切面和横切面剪切模量的正确性。结果表明:自由板扭转振形法适用于测定木材3个剪切模量GLT、GLR和GRT,其测定方法具有简单、快速、重复性好和精度高等优点; 实施自由板扭转振形法测定木材剪切模量的关键是测试自由板频谱,并从频谱图上正确识别出一阶扭转频率,推荐用互功率谱概念识别频谱图上的一阶扭转频率。</br>In the wood processing industry, since the sawn timber is the major material for wood structure buildings, furniture, wood flooring, etc., it is critical to examine the mechanical properties of timber. In order to investigate the principle and method for determining three shear modulus of wood by the dynamic free-plate torsional vibration, this study used the free-plate first-order torsional vibration shape and energy method to derive the relational formula between the wood shear modulus and free plate's first-order torsional frequency, and provide the vibration shape coefficients for the free plate's relational formula between width-to-length ratio and thickness-to-width ratio on the tangential section, radial section and transverse section. The values of shear modulus can be obtained not only by the calculation using the formula, but also using the table. Finally, the accuracies of the wood shear modulus of tangential section, radial section and transverse section obtained using the method of the free-plate torsional vibration were validated by the static and dynamic experiments. The results showed that the free-plate torsional vibration method is suitable for the determination of three shear modulus of wood(GLT, GLR and GRT), and the determination method is simple, rapid, reproducible and accurate; the key to the determination of the shear modulus of wood by the free-plate torsional vibration method is to test the free-plate spectrum, correctly identify the first-order torsional frequency from the spectrum, we recommend using cross power spectrum concept to identify the first-order torsional frequency on the spectrum
%K 自由板
%K 扭转振动
%K 振率
%K 剪切模量&lt
%K /br&gt
%K free plate
%K torsional vibration
%K vibration frequency
%K shear modulus
%U http://lkkf.njfu.edu.cn//oa/darticle.aspx?type=view&id=201604002