Effective shear stiffness of cross-laminated timber : Comparison between numerical and analytical approaches

Abstract: The increasing importance of sustainability has led to a focus on smart solutions for energy consumption and materials. Cross-laminated timber (CLT) has gained attention as a sustainable alternative in construction, offering high strength, stiffness, and dimensional stability. However, there is a lack of standardized methods for shear design of CLT members loaded in plane, leading to the use of simplified approaches. This study aims to investigate the effective shear stiffness of CLT using Finite Element Analysis (FEA) and validate analytical models. This is done through studying a small volume element “RVE” of a CLT panel. The software Abaqus, in conjunction with a Python script, is employed to analyze the impact of various layer thicknesses on the effective shear stiffness. Two FEA methods, namely the Geometric Method and the Energy Method, are utilized and compared against the hand-calculated models, namely the Analytical Method and the Analytical Method with a correction factor. The findings contribute to understanding the impact that different layer thickness combinations have on the shear stiffness of CLT. The limitations include specific cross-sectional dimensions, linear analyses, and the focus on five-layered CLT panels.The study compares different mesh sizes and element types in FEA and assesses the reliability of analytical and numerical methods. The Energy Method and the Geometric Method generally yield consistent and more conservative results, while the Analytical Methods tend to produce higher stiffness values. However, the Geometric Method exhibits inconsistencies in certain thickness combinations, suggesting modeling challenges. The results provide insights for designing and optimizing CLT panels, but further research and real-life experiments are recommended to validate the methods. Additionally, larger finite element models and improved surface constraints should be explored to improve accuracy.