[1]陈复明,江泽慧,王戈,等.单向及双轴向压缩载荷下的圆竹径向力学性能[J].深圳大学学报理工版,2012,29(No.6(471-580)):527-533.[doi:10.3724/SP.J.1249.2012.06527]
 CHEN Fu-ming,JIANG Ze-hui,WANG Ge,et al.Mechanical properties of bamboo with diametric uniaxial and biaxial compression tests[J].Journal of Shenzhen University Science and Engineering,2012,29(No.6(471-580)):527-533.[doi:10.3724/SP.J.1249.2012.06527]
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单向及双轴向压缩载荷下的圆竹径向力学性能()
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《深圳大学学报理工版》[ISSN:1000-2618/CN:44-1401/N]

卷:
第29卷
期数:
2012年No.6(471-580)
页码:
527-533
栏目:
材料科学
出版日期:
2012-11-30

文章信息/Info

Title:
Mechanical properties of bamboo with diametric uniaxial and biaxial compression tests
文章编号:
20120611
作者:
陈复明江泽慧王戈程海涛
国际竹藤中心, 国家林业局竹藤科学与技术重点实验室, 北京 100102
Author(s):
CHEN Fu-ming JIANG Ze-hui WANG Ge and CHENG Hai-tao
Key Lab of Bamboo and Rattan Science and Technology, International Center for Bamboo and Rattan, State Forestry Administration, Beijing 100102, P.R.China
关键词:
竹质工程材料 竹质构件 圆竹 双轴向压缩 尺寸效应 数字散斑相关方法 应变场 力学性能
Keywords:
bamboo engineering materials bamboo qualitative components bamboo biaxial compression size effect digital spackle correlation method strain-field mechanical properties
分类号:
TU 502+.6
DOI:
10.3724/SP.J.1249.2012.06527
文献标志码:
A
摘要:
研究圆竹在单向(x)和双轴向( x, y)压缩载荷下的径向力学行为.利用斜率法,估算双轴向载荷下竹间的长度尺寸效应;采用数字散斑方法,对应变场信息及长径比对环向应变的影响进行表征.结果表明:双轴向压缩强度是单向的2.4~2.5倍,压缩时间比单向减少30%~45%;双轴向载荷下竹节处强度是竹间的2.38倍,从结构方面看,竹节对竹筒是增强体而非缺陷.利用二参数Weibull分布函数,估算出双轴向压缩下的长度尺寸效应系数为0.056(x方向)和0.069(y方向), 双轴向载荷下破坏首先发生在与x/y轴大约成45°位置处.应变场分析表明:x方向应变分布较均匀,应变值变化区间为-0.138~0.096,均值为-0.006;y方向应变呈现较大波动,应变值变化区间为-0.372~0.437,均值为0.002;在45°位置处,竹环内侧靠近竹黄部位受压应力,竹环外侧靠近竹青部位受拉伸作用.在双轴向载荷0~300 N下,随着长细比增加,应变的25%~75%分位值和均值的绝对值总体上呈减小趋势.
Abstract:
Mechanical behaviours of bamboo at uniaxial (x) and biaxial (x, y) directions were investigated by diametric compression tests, and the long-size effects of bamboo under biaxial compression loadings were estimated by using the slope method. Meanwhile, the information of strain-filed and the effects of ration length/radius on strain were characterized by the digital speckle correlation method. The strength with biaxial texts was 2.4~2.5 times as hard as that of the uniaxial while compression time was 30%~45% less than that of the uniaxial. The strength of bamboo joint under biaxial compression loadings was 2.38 times as hard as its near parts at intermodal region, so, it acts as reinforcement for the bamboo and not a defect in its structure. The size effects of length under biaxial compression loading were 0.056(x-direction) and 0.069(y-direction)with the help of 2P-Weibull distribution functions. Failure occurs at an about 45°position with x/y axial firstly when conducting biaxial compression. The x-strain distribution was uniform. The range of variation was -0.138~0.096, and the mean value was -0.006. However, variation of y-strain field presented a more fluctuation compared with x-strain filed, as the range of variation was -0.138~0.096, the mean was -0.006. The location at 45° near the inner circle of bamboo ring suffered compression stress, conversely, the position close to the outside of the ring was given stretched effect. As the increase of length-diameter ratio, 25th~75th percentiles of strain value and absolute value of mean, as a whole, presented a decreasing trend under biaxial loads 0~300 N.

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备注/Memo

备注/Memo:
Received:2010-12-13;Revised:2012-05-30;Accepted:2012-07-28
Foundation:National Forestry Public Welfare Scientific Research Program of China (201204701)
Corresponding author:Staff Scientist WANG Ge. E-mail: wangge@icbr.ac.cn
Citation:CHEN Fu-ming, JIANG Ze-hui, WANG Ge, et al.Mechanical properties of bamboo with diametric uniaxial and biaxial compression tests[J]. Journal of Shenzhen University Science and Engineering, 2012, 29(6): 527-533.(in Chinese)
基金项目:国家林业公益性行业专项资助项目(201204701)
作者简介:陈复明(1985-), 男(汉族), 安徽省天长市人, 国际竹藤中心博士研究生. E-mail:chenfuming1985@126.com
引文:陈复明,江泽慧,王戈,等. 单向及双轴向压缩载荷下的圆竹径向力学性能[J]. 深圳大学学报理工版,2012,29(6):527-533.
更新日期/Last Update: 2012-11-30