Abstract
The structural contribution of entasis, the subtle curvature observed in classical columns such as those in the Parthenon (ancient Greece) and Horyu-ji Temple (Japan), was investigated. The study employed a two-segment-width beam model for both traditional buckling analysis based on the bending beam theory and physical experimentation to determine its effect on column strength. The results indicated that, when the two-segment-width beam was treated as a two-dimensional experiment of entasis, it was confirmed that the buckling load increased. This increase was observed under specific conditions when compared against straight beams of uniform width and two-segment-width beams sharing the same projected area. The investigation reconfirms that the traditional architectural style of entasis in columns provides a verifiable structural strengthening benefit.