Initial shapes of stress-strain curve of wood specimen subjected to repeated combined compression and vibration stresses and the piezoelectric behavior
Initial shapes of stress-strain curve of wood specimen subjected to repeated combined compression and vibration stresses and the piezoelectric behavior
复制标题
重复压缩和振动联合应力作用下木材试样应力-应变曲线的初始形状和压电行为
DOI：
10.1007/s10086-005-0801-0
复制
发表时间：
2006
影响因子：
2.9
通讯作者：
T. Nakao
中科院分区：
文献类型：
--
作者：
T. Nakai;Hiroyuki Yamamoto;M. Hamatake;T. Nakao
研究了在纤维方向与载荷方向夹角不同的反复组合压缩和振动应力作用下，圆木试件的应力(σ)-应变（ε）曲线初始形状与压电性能的关系。主要研究结果有：(1)σ-ε曲线先呈凸形，然后应力与应变成正比；在加载和卸载过程中，σ-ε曲线的形状基本一致。(2) σ-压电电压(P)曲线是非线性的，在加载和卸载过程中，曲线上存在一个最大值或顶点，其形状基本相同，σ-ε曲线也是如此。(3)应力[dσ/dε（=σ′）]对ε的一阶导数曲线为非线性曲线。各角度下的σ′-ε和p -ε曲线基本相似。(4) σ- p曲线最大值处的应力随纤维方向与载荷方向夹角的增大而减小。应力的变化趋势与胡克定律计算的杨氏模量和汉金森定律计算的抗压强度非常相似。
This study investigated the relationship between the initial shape of the stress (σ)-strain (ε) curve of aChamaecyparis obtusawood specimen subjected to repeated combined compression and vibration stresses at various angles between the fiber direction and load direction and the piezoelectric behavior. The main findings of the study are: (1) theσ-εcurve became convex initially, and then the stress was proportional to the strain. Theσ-εcurve had almost the same shape during both loading and unloading. (2) Theσ-piezoelectric voltage (P) curve was nonlinear, with a maximal point or cusp on the curve, which had almost the same shape during both loading and unloading, as was also observed for theσ-εcurve. (3) The plot of the first derivative of the stress [dσ/dε(=σ′)] againstεwas nonlinear. Theσ′-εandP-εcurves at various angles were fairly similar. (4) The stress at the maximal point (or cusp) of theσ-Pcurve decreased with an increase in the angle between the fiber direction and load direction. The tendency of the stresses was very similar to that of Young’s modulus and compression strength calculated from Hook’s law and Hankinson’s law, respectively.