This video shows an aluminium alloy plate girder being load tested in bending. The test specimen and load test have been designed to demonstrate local buckling in the web of the section.

Learning Outcomes:

Viewers will gain an improved understanding of:

• Local buckling effects in beams.
• The importance of providing adequate stiffeners to resist shear buckling
• The effect of shear buckling on the stiffness of a beam

The girder is laterally and torsionally restrained in four locations. It is then subjected to four point bending. The test specimen exhibits local buckling in the web of the section. As expected, no buckling occurs in the middle third of the beam, where there are no shear stresses acting. As shear buckling occurs, the beam experiences a sudden reduction in stiffness until permanent plastic deformation occurs.

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