东北落叶松材单向顺纹受拉损伤模型

发布时间：2018-04-13 11:44

本文选题：木材 + 顺纹受拉　；参考：《湖南大学学报(自然科学版)》2017年11期

【摘要】：从细观层次揭示木材顺纹受拉破坏的损伤演化机制,是建立木材损伤本构模型的基础.在分析木材宏观及细观构造特征的基础上,将木材等效为若干根并联的受拉木纤维,每根顺纹受拉木纤维等效为弹脆性的受拉微弹簧.基于概率思想,假定受拉微弹簧的极限应变Δ为服从某一分布形式fΔ(x)的随机变量,推导了木材顺纹受拉损伤演化方程.在正确设置木材声发射参数即峰值定义时间(PDT)、撞击定义时间(HDT)和撞击闭锁时间(HLT)的基础上,通过木材顺纹受拉试件破坏过程中的声发射试验确定了受拉木纤维极限应变分布函数的参数,进而建立了木材顺纹受拉损伤模型.分析结果表明,声发射累计振铃计数与木材顺纹受拉细观损伤的累积过程是一致的,可用于反映木材顺纹受拉过程中的损伤演化特征.
[Abstract]:It is the foundation of the constitutive model of wood damage to reveal the damage evolutional mechanism of wood progressive tensile damage from the meso level.On the basis of analyzing the macroscopical and meso-structural characteristics of wood, the wood is equivalent to a number of parallel pulled wood fibers, and each tensioned wood fiber is equivalent to an elastic brittle tensile micro-spring.Based on the theory of probability, assuming that the limit strain 螖 of the tensile microspring is a random variable from a certain distribution form f 螖 x, the evolution equation of the tensile damage of wood is derived.Based on the correct setting of wood acoustic emission parameters, i.e., peak defining time (PDT), impact definition time (HDT) and impingement latching time (HLTT),The parameters of the ultimate strain distribution function of the tensioned wood fiber were determined by acoustic emission (AE) test during the damage process of wood tensile specimens, and the tensile damage model of wood was established.The results show that the cumulative ringing number of acoustic emission is consistent with the cumulative process of progressive tensile damage of wood, and it can be used to reflect the damage evolution characteristics of wood in the process of progressive tension.
【作者单位】：西安建筑科技大学土木工程学院;机械工业勘察设计研究院有限公司;
【基金】：国家自然科学基金资助项目(51278399) 陕西省自然科学重大基础研究项目(2016ZDJC-23) 国机集团科技发展基金资助项目(13科192号) 西安建筑科技大学创新团体资助计划~~
【分类号】：TU531.1

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