Investigating the Scaling Effect of 3D-Printed Synthetic Hollow Section Beams

Traditional full-scale experimental testing of structural elements takes a significant amount of time, effort, and resources. To overcome the abovementioned issues associated with full-scale experimental testing, similitude theory has been introduced by producing a scaled-down model of the original element to be tested. Previous studies examined different materials and shapes in scaling a prototype using similarity analysis. However, little work has been done on utilizing Additive Manufacturing (AM) technology to produce scaled-down physical models of structural elements, specifically, a standard rectangular hollow structural section (HSS). To address this gap, the scaling effect of 3D-printed simply supported HSS beams was investigated. A generic similarity relationship was established for simply supported rectangular HSS. Physical scaled-down samples of different sizes were produced using AM technology and tested subsequently. The printing time and material required for each sample were used to develop scaling curves that can estimate the time and material necessary for any other simply supported hollow section. A three-point bending test was carried out for the printed samples. Experimental results were used to establish scaling curves that predict the ultimate load of a full-scale hollow beam. The results were verified by performing finite element analysis (FEA) using ABAQUS. The load-deflection behavior predicted from the FEA model was in good agreement with the behavior obtained from the scaling curve formula. The proposed methodology paves the way for feasible and cost-effective modeling of HSS beams, as new materials and manufacturing techniques can be studied. For future work, the effect of printing configurations namely infill pattern and printing direction on the structural behavior of the printed models will be investigated.