Determination of the moisture change behavior of cross-laminated timber using an optical flow based computer vision technique

Although cross-laminated timber (CLT) offers greatly improved directional stability against moisture changes compared to lumber, some layup dependent directional differences still remain. Furthermore, even under a purely homogeneous distributed moisture change strong deformations appear along the boundaries, which show a decrease of swelling/shrinkage towards the inside of CLT panels. Metrological determination of this behavior is still a challenging task and involves long-lasting moisture content conditioning and typically manual measurements. This limits the amount of measurable data-points and thus the gain-able insights.
We apply a recently introduced computer vision technique based on optical flow from scan images to measure surface deformation fields of various CLT specimens with different layups. This allows us to measure the change of average differential swelling and shrinkage coefficients …