共查询到17条相似文献,搜索用时 125 毫秒
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西藏部分古建筑腐朽与虫蛀木构件的PILODYN无损检测研究 总被引:1,自引:0,他引:1
对西藏布达拉宫和罗布林卡不同地方更换下来的杨木、沙棘和白叶柳旧木构件进行了PILODYN现场无损检测,得到了木构件腐朽与虫蛀程度的定量结果;根据GB/T 13942.2-92对每根旧木构件进行了肉眼表面腐朽分级,得到了旧木构件腐朽与虫蛀程度的定性判断结果,将二者进行对比分析和讨论,说明PILODYN无损检测设备用于古建筑木构件的腐朽与虫蛀程度检测是完全可行的,同时强调了PILODYN无损检测设备使用过程中的局限性. 相似文献
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原木内部腐朽应力波二维图像的获取与分析 总被引:2,自引:1,他引:1
应用Arbotom应力波检测系统,对东北林区3个针叶树种(云杉、冷杉、落叶松)和9个阔叶树种(白桦、色木、椴木、杨木、水曲柳、核桃楸、榆木、铁木和柞木)的原木内部腐朽进行检测,并对原木内部腐朽面积的实际估算值和检测估算值进行比较分析.结果表明:Arbotom应力波无损检测系统可以获取原木内部腐朽的二维图像,但检测准确率较低,建议采用多点测量和改进应力波测试仪器,以提高检测准确率. 相似文献
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基于应力波与X射线二维CT图像原木内部腐朽无损检测 总被引:3,自引:0,他引:3
木材无损检测技术是在20世纪60年代后逐步兴起的对木材性质进行非破坏性检测的技术,如今该技术已多达几十种,产生了多种多样的木材无损检测方法。为了更好地运用这些方法,找出它们的优缺点,有必要对它们检测木材内部缺陷进行试验和评价。同时使用应力波和X射线两种方法对原木内部腐朽进行检测,结果表明:应力波和X射线二维CT图像都能检测出原木内部腐朽,显示出腐朽的区域,而且能利用图像计算出腐朽区域的面积。两种方法计算出的腐朽区域的面积准确度φ都较高,但是应力波二维CT图像在其他许多方面逊于X射线二维CT图像:应力波二维CT图像对腐朽区域形状的显示不够准确,不能根据图像辨别出腐朽的严重程度,利用图像确定腐朽面积效率很低;X射线二维CT图像对腐朽区域形状的显示与实际较吻合,可以根据图像辨别出腐朽的严重程度,利用图像确定腐朽面积效率高。但是X射线仪器笨重不便携,而应力波检测仪轻快便携。 相似文献
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应力波用于木材和活立木无损检测的研究进展 总被引:2,自引:0,他引:2
在简单介绍应力波无损检测技术的基本原理、特点以及目前应力波主要的检测设备同时,对国内外应力波无损检测技术在木材和活立木领域的研究进展做了叙述,分析了现阶段应力波无损检测技术存在的问题,并对应力波无损检测技术进一步发展做了展望。 相似文献
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应力波在旱柳立木内的传播规律分析及其安全评价 总被引:3,自引:0,他引:3
应用应力波对东北林业大学校园内的40株旱柳进行检测,获取样本树120个横断面的二维应力波图像及波速矩阵.依据图像,把立木横断面腐朽状况分为尤腐朽、心腐、边腐、心腐边腐共存断面等4类.进一步分析表明:应力波在健康立木横断面内径向传播速度最快,并且波从某一传感器到其余传感器(按顺时针计)的速度变化是先增后减的趋势;立木腐朽会导致应力波传播速度降低,应力波在心腐立木横断面内传播趋势不是先增后减,而变成非常平坦的曲线.因此,可以利用应力波波速的变化来对立木内部腐朽进行估计.另外,根据应力波检测成像结果可以识别腐朽面积及位置,并能够依据断面t/R值对旱柳行道树的安全性进行初步评价. 相似文献
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SHANG Dajun DUAN Xinfang HE Xiaocui LI Jianing WANG Ping . College of Mechanical Electronic Engineering Northwest Agriculture Forestry University Yangling P.R.China . Research Institute of Wood Industry Chinese Academy of Forestry Beijing P.R.China 《中国林业科技(英文版)》2007,6(4):20-24
Visual classification and stress wave non-destructive testing technology were adopted to evaluate the decay status of ancient Populus wood members (rafters) replaced from the Potala Palace. The decay status of wood members was evaluated by stress wave testing and visual observation. For most of the ancient wood members, the evaluation results by two methods were consistent with each other. Also stress wave testing techniques can find the internal wood member decay to eliminate the hidden hazard for ancient wood members, and offer relatively accurate quantitative information for the safety status of ancient wood members. Thus during the maintaining for ancient architectures, visual observation combined with stress wave testing techniques is a good way to evaluate the degradation of ancient wood members. 相似文献
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介绍了古建筑木构件勘查中常用的无(微)损检测技术,阐述了各种仪器工作原理、检测方法及其优缺点,其中包括皮罗钉、阻力仪、应力波和超声波检测设备。基于以上技术,结合古建筑木构件特点,提出仪器结合使用、构件分类检测、设备便携化以及以树种鉴定为基础的木结构古建筑无损评估体系。Abstract: Commonly used nondestructive inspection technologies involved in the survey of the wood structures of ancient buildings are introduced and the inspection methods,working principle,advantages and disadvantages of various instruments,including of pilodyn,re 相似文献
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In order to improve the accuracy and reliability of identifying wood defects and to realize the maximum wood utilization of trees, we employed an experimental method to test the stress wave propagation velocity in standing Fraxinus mandshurica trees selected from the Harbin Forest Experimental Station in winter. Thirty standing trees in good conditions were taken as test specimens and stress wave propagation velocities were measured using a FAKOPP Microsecond Timer in trees in both fall and winter. The test data were processed with the aid of Excel and SPSS software. The results show that 1) the velocities in longitudinal and radial stress wave propagation in frozen F. mandshurica trees were much higher than those in the non-frozen trees; 2) there was a highly positive correlation between longitudinal stress wave propagation velocity in frozen and non-frozen states, with a correlation coefficient of 0.82, as well as a positive correlation between radial stress wave propagation velocity in frozen and non-frozen states with a correlation coefficient of 0.87; 3) in the frozen state, the longitudinal stress wave propagation velocity was significantly affected by the moisture content (MC) of standing tree, while it was not obvious in the non-frozen state and 4) the radial stress wave propagation velocity was not significantly affected by MC in either frozen or non-frozen state. 相似文献
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Sangdae Lee Sang-Joon Lee Jong Su Lee Ki-Bok Kim Jun-Jae Lee Hwanmeyong Yeo 《Journal of Wood Science》2011,57(5):387-394
Most old buildings in Korea are wood framed and, with age, deterioration is found in all wood components of antique buildings.
Insects and rapid changes in humidity are among the main causes of deterioration. To preserve antique wooden buildings, nondestructive
testing (NDT) methods are required. Various methods of nondestructive evaluation (NDE) such as X-ray, stress wave, drilling
resistance test, and ultrasound are used to inspect the safety of wooden antique buildings. The ultrasonic method is relatively
simple, inexpensive, and accurate. The rafters are one of the main components of antique buildings and are seriously affected
by deterioration. This study aimed to develop a nondestructive ultrasonic technique for evaluation of wooden rafter deterioration.
Regression models describing the relationship between the artificial deterioration of the specimen and ultrasonic parameters
were proposed. The method was found to be reliable for evaluating wooden rafter deterioration. 相似文献
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对尾巨桉(Eucalyptus urophylla×E.grandis)无性系人工林隔行间伐和不间伐(对照)处理下的植株树冠和木材物理材性进行调查和测定。结果表明:间伐后第3年,尾巨桉无性系的树冠高度、冠幅半径、FAKOPP应力波速度、生长应变和Pilodyn值与对照相比,无显著差异;冠幅半径在东、南、西、北4个方向间存在显著差异,方向间的差异性受间伐影响;2个营林处理下的冠幅均向西、南2个方向间的区域偏移;FAKOPP应力波值在4个测定方向间无显著差异;对照和间伐处理下的生长应变各测定方向间均存在显著差异,但不同测定方向间的Pilodyn值无显著差异;各测定性状间无显著相关关系。由此说明,隔行间伐措施可调节树冠空间分布,但不影响林分树冠大小和主要木材物理材性。 相似文献