Microscopic X-ray computed tomography (XµCT) aided finite element (FE) modelling is a popular method in material science to relate material properties to heterogeneous microstructures. Recently, a methodology was developed for the XµCT aided FE modelling of wood, which characterises the process from specimen preparation to estimation of material properties. In the current research, this methodology is tested on branches of Norway spruce (Picea abies (L.) Karst.) to estimate the hygroexpansion coefficients of opposite (OW) and compression wood (CW). These properties are largely unknown and have engineering implications. The study is complemented by measurements of density, moisture content (MC) and elastic moduli. Results showed that the methodology assisted in the design of an integrated process and the identification of bottlenecks. It was seen that the level of detail of the numerical model had a strong influence on the obtained hygroexpansion properties. CW from branches showed higher density and longitudinal shrinkage coefficients, and elastic moduli less affected by MC. These differences are unlikely caused by MC, but more likely by the characteristics of the microstructure.

中文翻译：

---

显微计算机断层扫描辅助有限元建模作为估计木材吸湿膨胀系数的方法：软木树枝中相对和压缩木材的案例研究

显微 X 射线计算机断层扫描 (XµCT) 辅助有限元 (FE) 建模是材料科学中将材料特性与异质微观结构联系起来的一种流行方法。最近，开发了一种用于 XμCT 辅助木材有限元建模的方法，该方法描述了从样本制备到材料特性估计的过程。在当前的研究中，这种方法在挪威云杉的树枝上进行了测试（云杉(L.) 喀斯特.) 来估计相对木材 (OW) 和压缩木材 (CW) 的吸湿膨胀系数。这些特性在很大程度上是未知的，并且具有工程意义。该研究还辅以密度、水分含量 (MC) 和弹性模量的测量。结果表明，该方法有助于集成流程的设计和瓶颈的识别。可以看出，数值模型的详细程度对获得的吸湿膨胀性能有很大影响。来自枝条的 CW 显示出较高的密度和纵向收缩系数，并且弹性模量受 MC 的影响较小。这些差异不太可能是由 MC 引起的，而更有可能是由微观结构的特征引起的。