Shape Optimization and Experimental Investigation of Glue-Laminated Timber Beams

Area of Science:

• Structural engineering
• Materials science
• Timber construction

Background:

• Glue-laminated timber (GLT) is a key construction material.
• Optimizing beam shapes can enhance structural performance and material efficiency.
• Understanding anisotropy and boundary conditions is crucial for GLT beam design.

Purpose of the Study:

• To determine the optimal shapes for glue-laminated timber beams.
• To minimize material usage (Vmin) for a fixed load-carrying capacity (LCC).
• To maximize load-bearing capacity (Qmax) for a fixed beam volume.

Main Methods:

• Formulated a control theory problem for beam shape optimization.
• Employed Pontryagin's maximum principle (PMP) for optimization.
• Utilized Dircol v. 2.1 software and 3D finite element analysis (FEA) in Abaqus.
• Produced and tested optimized beams (Vmin and Qmax) against reference beams.

Main Results:

• The Vmin optimization successfully reduced material usage by approximately 12.9% with comparable LCC.
• The Qmax optimization was less successful due to the high variability of GLT mechanical properties.
• Experimental results generally aligned with theoretical predictions for Vmin beams.

Conclusions:

• Shape optimization is effective for reducing material consumption in GLT beams.
• GLT material property variability poses challenges for maximizing load-bearing capacity through shape optimization.
• Further research into material characterization could improve Qmax optimization strategies.