Long-term behaviour of Norway spruce glulam loaded perpendicular to grain
Long-term behaviour of Norway spruce glulam loaded perpendicular to grain
复制标题
垂直于纹理装载的挪威云杉胶合板的长期性能
DOI：
10.1007/s00107-019-01437-4
复制
发表时间：
2019
影响因子：
2.6
通讯作者：
K. Malo
中科院分区：
文献类型：
--
作者：
Francesco Mirko Massaro;K. Malo
木材在垂直于纹理的压缩载荷下的力学性能对于许多木结构的合理设计是必不可少的。经常承受这种荷载的结构部件包括底部栏杆上的立柱、应力层压木甲板、位于垂直承重柱之间的木构件以及传统的受压木接头配合面。在当前的欧洲木结构法规以及正在进行的下一代欧洲规范5-木结构的工作中，垂直于纹理的压缩一直是一个反复讨论的话题。然而，长期的行为是相当复杂的，考虑到时间和水分的变化，并提高理解和能力，考虑在实际设计中的长期影响，本文给出了一个简化的一维模型。本文提出了新的结果，从长期压缩正交粮食试验进行负载和水分控制。测试的目的是评估横向蠕变对木材构件长期行为的影响，包括机械吸附变形的影响。测试结果又被用来校准一个一维模型的预测木材的长期响应。该模型考虑了负荷和湿度变化的综合影响。有效的材料特性是通过使用有效的髓部位置连同正交各向异性材料参数来定义的。最后，模型结果和实验观察之间的比较，显示出整体良好的预测响应。
The mechanical behaviour of timber loaded in compression perpendicular to grain is essential for a rational design of many timber structures. Structural components frequently exposed to such loading include studs on bottom rails, stress-laminated timber decks, timber elements lying in between vertical load-bearing columns as well as traditional timber joints mating surfaces in compression. Compression perpendicular to grain has been a repeated topic for discussion both in the current European regulations for timber structures, as well as in the ongoing work with the next generation of Eurocode 5-timber structures. However, the long-term behaviour is quite complex, taking both time and moisture variation into consideration, and to improve the understanding and the ability to consider the long-term effects in practical design, a simplified one-dimensional model is given herein. The paper presents novel results from long-term compression orthogonal to grain tests performed with load and moisture control. The purpose of the testing was to evaluate the effect of transversal creep on the long-term behaviour of timber elements including the effect of the mechanosorptive deformation. The test results were in turn used to calibrate a one-dimensional model for the prediction of the long-term response of timber. The model takes into account the combined effects of loading and moisture variations. The effective material properties are defined by use of effective pith locations together with the orthotropic material parameters. Finally, a comparison between the model results and experimental observations is given, showing an overall good prediction of the response.