Compressive fatigue in wood
Compressive fatigue in wood
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木材的压缩疲劳
DOI：
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发表时间：
2000
影响因子：
3.4
通讯作者：
L. Damkilde
中科院分区：
文献类型：
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作者：
C. O. Clorius;M. U. Pedersen;P. Hoffmeyer;L. Damkilde
摘要 对木材在平行于纹理的压缩载荷循环下的疲劳破坏进行了研究。在对应于短期强度 80% 的应力激发水平下，在方波形成的疲劳载荷下，对云杉的小透明样本进行破坏。使用从 0.01Hz 到 10Hz 的四种频率。人们发现，失效循环次数并不能很好地衡量木材的疲劳性能。在整个疲劳测试过程中都会监测蠕变、最大应变、刚度和功。建议将累积蠕变与损坏一起识别，并观察到刚度降低和累积蠕变之间存在相关性。拒绝基于疲劳寿命期间总功的失效模型，并通过实验支持基于弹性、粘性和非恢复粘弹性功的修改功模型，并尝试在微观结构水平上进行解释。给出了解释荷载持续时间效应和荷载序列效应之间相互作用的模型概要。
Summary An investigation of fatigue failure in wood subjected to load cycles in compression parallel to grain is presented. Small clear specimens of spruce are taken to failure in square wave formed fatigue loading at a stress excitation level corresponding to 80% of the short term strength. Four frequencies ranging from 0.01 Hz to 10 Hz are used. The number of cycles to failure is found to be a poor measure of the fatigue performance of wood. Creep, maximum strain, stiffness and work are monitored throughout the fatigue tests. Accumulated creep is suggested identified with damage and a correlation is observed between stiffness reduction and accumulated creep. A failure model based on the total work during the fatigue life is rejected, and a modified work model based on elastic, viscous and non-recovered viscoelastic work is experimentally supported, and an explanation at a microstructural level is attempted. The outline of a model explaining the interaction of the effect of load duration and the effect of the loading sequences is presented.