Some aspects of the rheological behaviour of wood part IV: Non-linear behaviour at high stresses in bending and compression
Some aspects of the rheological behaviour of wood part IV: Non-linear behaviour at high stresses in bending and compression
复制标题
木材流变行为的某些方面第 IV 部分：弯曲和压缩高应力下的非线性行为
DOI：
10.1007/bf00351580
复制
发表时间：
1972
影响因子：
3.4
通讯作者：
B. Budgen
中科院分区：
文献类型：
--
作者：
R. Kingston;B. Budgen
摘要 木材在弯曲过程中的流变行为中与应力的非线性关系早先已被证明在出乎意料的低应力下发生。对另外一种树种——高山白蜡木的研究进一步证实了这一点。对环松（之前研究弯曲的树种之一）的测试表明，在压缩过程中，非线性首先发生在应力处，该应力占极限应力的比例比弯曲时高得多，但与实际应力的范围大致相同。这表明在如此低的弯曲应力下产生非线性的原因在于压缩强度远低于弯曲强度。当弯曲应力达到弯曲比例极限时，梁受压面上的应力达到极限抗压强度的较高百分比，梁中的非线性效应主要归因于受压面附近的应力。即使在 20 至 50°C 范围内，也发现温度对环松受压总蠕变分数有显着影响，在此范围内蠕变增加了约 2.5 倍。
SummaryThe incidence of non-linearity with stress in the rheological behaviour of wood in bending was shown earlier to occur at an unexpectedly low stress. This has been further confirmed by the study of an additional species, alpine ash.Tests on hoop pine, one of the species previously studied in bending, have shown that in compression, non-linearity first occurs at stresses which are a much higher fraction of the ultimate stress than in bending, but in approximately the same range of actual stress. This suggests that the cause of non-linearity at such a low stress in bending lies in the fact that the compressive strength is considerably lower than the bending strength. The stress on the compression face of a beam reaches a high percentage of the ultimate compressive strength by the time the bending stress reaches the limit of proportionality in bending and the nonlinear effects in a beam are attributable mainly to stresses near the compression face.A marked effect of temperature on fractional total creep for hoop pine in compression was found even within the range 20 to 50° C, the creep increasing by a factor of about 2.5 in this range.