Modeling Crack Behavior around Holes in Glulam Beams Using the WoodST Constitutive Model Based on Continuum Damage Mechanics

Abstract The integration of service holes in glulam beams is increasingly common in mass timber construction; however, these openings introduce stress concentrations that can compromise structural integrity through crack initiation and propagation. This study presents a robust numerical framework for simulating crack behavior around holes in glulam beams using the finite element software Abaqus. The framework incorporates the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper W o o d Superscript upper S upper T" display="inline" overflow="scroll"> <mml:msup> <mml:mi>Wood</mml:mi> <mml:mi>ST</mml:mi> </mml:msup> </mml:math> constitutive model, developed based on continuum damage mechanics, to capture the anisotropic damage evolution of timber under tensile and shear loading. Key modeling components include detailed geometric representation, layer-refined meshing strategies, and cylindrical orthotropic material systems to simulate the structure of the laminations. To validate the proposed approach, six glulam beams with three configurations—without holes, with a single hole, and with two holes—were tested under a single point load at midspan. The developed finite element models were calibrated and validated using experimental data, demonstrating strong agreement in terms of load–displacement responses and observed failure modes. The results confirm the model’s capability to predict the structural resistance and deformation behavior of perforated glulam beams. This predictive tool contributes to the advancement of structural design methodologies for engineered timber structures.