EM-116 | Unsymmetrical Bending Apparatus

Symmetrical bending of a beam – also known as uniaxial bending – occurs when the load plane coincides with one of the main axes of the beam cross-section. The beam then deflects in the direction of the load and can be described by elastic lines. In unsymmetrical bending of a beam – also known as complex or biaxial bending – the main axes of the cross-section do not coincide with the direction of loading. To prevent torsion, the line of application of the load must pass through the shear center. If it does not, the beam undergoes combined bending and torsion loading. This apparatus is used to perform experiments relating to unsymmetrical bending. The beam under investigation is clamped into place on one end and loaded down at the free end. Two dial gauges record the horizontal and vertical deformation of the beam. The unit includes three beams with different cross-sectional profiles: I, L and U. The beam can be clamped with freedom to rotate in any direction. This enables investigation of loading along the main axis or of the general load case. An angle scale at the clamping point indicates the angular position of the beam. It is possible to adjust the load application point eccentrically, so that purely unsymmetrical bending or combined bending and torsion loading is investigated.