Abstract Changes in relative humidity of the ambient air, RH (%), cause wetting and drying of wood material, which results in non-uniform moisture contents or moisture gradients, and consequently in moisture-induced stresses and strains in the glued-laminated timber (glulam) members. The aim of the present paper is to perform a hygro-mechanical analysis to predict the mechanical behavior of glulam specimens exposed to two RH regimes, causing wetting from 50% to 90% RH and drying from 90% to 50% RH, and compare the numerical to the experimental results. The aims are also to quantitatively analyze the influence of characteristic material parameters required in the multi-Fickian moisture transport model and the mechanical model on moisture-induced strains and stresses in glulam specimens and to determine the possibility of cracking of the material by analyzing the maximum tensile stresses perpendicular to the grain. Accurate numerical predictions of moisture contents and moisture-induced strains are obtained in the glulam specimens during wetting and drying as compared to the experimental results. The influence of a particular characteristic material parameter on moisture-induced strains and stresses is characterized as significant, but not crucial when a rough numerical estimation of the mechanical behavior of the glulam beam exposed to RH changes is required.

中文翻译：

---

胶合层压木材中水分引起的应变和应力的数值分析

摘要 环境空气相对湿度 RH (%) 的变化会引起木材的润湿和干燥，从而导致不均匀的水分含量或水分梯度，从而导致胶合层压木材中水分引起的应力和应变。 (胶合木) 成员。本论文的目的是进行湿力学分析，以预测胶合木样品暴露于两种相对湿度条件下的力学行为，导致从 50% 到 90% RH 润湿，从 90% 到 50% RH 干燥，并比较实验结果的数值。目的还在于定量分析多菲克水分传输模型和力学模型中所需的特征材料参数对胶合木试样中水分引起的应变和应力的影响，并通过分析最大值来确定材料开裂的可能性。垂直于晶粒的拉伸应力。与实验结果相比，在润湿和干燥过程中，胶合木样品中的水分含量和水分引起的应变的准确数值预测是获得的。当需要对暴露于 RH 变化的胶合木梁的机械行为进行粗略的数值估计时，特定特征材料参数对湿气引起的应变和应力的影响被认为是重要的，但并不重要。