this video shows a pin-ended column of low slenderness being tested in compression this type of specimen is commonly referred to as a stocky column the specimen is a rectangular Hollow section made of structural steel the length has been chosen such that the failure is dominated by the material strength the loading diagram shows a purely axial compressive Force evenly applied to both ends of the specimen the testing rig is now starting to apply a compressive Force to the specimen we can see the top end displacing and the column begins to deflect sideways as a result of
the material damage which can be seen at midspan on the concave side once this occurs the column begins to lose its load carrying capacity this particular phenom is not in the elastic but in the plastic range therefore the failure is governed by the material rather than the geometry of the specimen turning the specimen to the side you can see that the deformation has localized to the midspan of the specimen in a plastic hinge the graph initially shows a linear relationship between for and displacement in this range no cers displacement has taken place however ever once
failure takes hold the slope begins to reduce rapidly and the point at which the curve becomes flat marks the failure load
