Development of tension and compression creep models for wood using the time-temperature superposition principle
Development of tension and compression creep models for wood using the time-temperature superposition principle
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发表时间：
1997
影响因子：
0.9
通讯作者：
B. H. Bond;J. Loferski;J. Tissaoui;S. Holzer
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文献类型：
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作者：
B. H. Bond;J. Loferski;J. Tissaoui;S. Holzer
本文介绍了木材在拉伸和压缩的长期蠕变模型的发展，使用时间-温度叠加原理（TTSP）。在受控环境中进行了拉伸和压缩的短期加速蠕变试验。所测试的标本包括南方松（Pinus spp.），花旗松（Pseudotsuga menziesii）和黄杨（鹅掌楸）。测试温度范围为20° C至80°C。用于测试平行于纹理的张力的含水量（MC）对于花旗松和南方松分别为6%、9%和12%，对于黄杨分别为6%和9%。在平行于纹理的压缩试验中，花旗松和南方松的MC分别为9%和12%，黄杨为6%、9%和12%。应变是用粘贴应变片测量的。针对对数时间轴绘制每个温度的个体顺应性曲线，以获得主曲线。然后绘制温度偏移因子关系。非线性回归分析用于估计模型参数。结果表明，TTSP成功地应用于所有三个物种测试在MC刚刚指出在拉伸和压缩。TTSP的成功是由平滑拟合的主曲线，符合阿克里尼乌斯方程，并在公布的结果范围内的活化能。
This paper describes the development of long-term creep models for wood in tension and compression using the time-temperature superposition principle (TTSP). Short-term accelerated creep tests were conducted in both tension and compression in a controlled environment. The tested specimens include southern pine (Pinus spp.), Douglas-fir (Pseudotsuga menziesii), and yellow-poplar (Lirodendron tulipifera). Test temperatures ranged from 20° to 80°C. The moisture contents (MCs) for testing tension parallel to the grain were 6, 9, and 12 percent for Douglas-fir and southern pine, and 6 and 9 percent for yellow-poplar. The MCs for testing in compression parallel to the grain were 9 and 12 percent for Douglas-fir and southern pine, and 6, 9, and 12 percent for yellow-poplar. The strain was measured using bonded strain gauges. The individual compliance curve for each temperature was plotted against the log-time axis to obtain a master curve. The temperature shift-factor relationship was then plotted. A nonlinear regression analysis was used to estimate the model parameters. The results show that the TTSP was successfully applied to all three species tested at the MCs just stated in both tension and compression. Success of the TTSP was supported by smooth-fitting master curves, conformance to the Arrhenius equation, and the activation energies falling within published results.