Experimental setup for beams with adjustable rotational stiffness: An educational perspective

Abstract

In structural analysis, the rotations of beams' supports are considered either completely fixed or completely free. Therefore, supports are idealized as fixed, pinned (hinged), or roller. In real structures, regarding rotation, the support behavior is neither fully rigid nor completely free and shows a semi-rigid behavior in most cases. In this study, an educational test setup was created for a beam with semi-rigid supports to examine the effect of semi-rigid support on structural behavior. In this experimental setup, support conditions with different rotational stiffness can be obtained from pinned support to fixed support, which can be easily changed between the pinned and the fixed support. The physical equivalent of the rotational stiffness concept is shown in an easy and understandable way with the theoretical equations. A simulation tool based on the derived analytical equation is also developed using Mathematica Software. The simulation tool provides the users with a way to visualize the deformation of the system. The results of beam tests with different support conditions were compared with the results of the simulation, and the effects of semi-rigid support on the beam behavior were shown. The results revealed that the semi-rigid supported beam assembly created can also be used to examine the behavior of frame beams under vertical load. These simple novel experimental setup and simulation tools provided are convenient and useful approaches to demonstrate the structural concepts, including the semi-rigid support and behavior of beams in a frame structure.