ABSTRACT
Buckling is loss of stability due to geometric effects rather than material failure. But it can lead to material failure and collapse if the ensuing deformations are not restrained. The load capacity for long slender columns will be controlled by buckling, as opposed to the crushing strength of the material. The bifurcation loads, one for every possible mode of buckling, are fairly easy to obtain using commercial software. The geometry of the structure is that of the perfect undeformed configuration, loaded with the nominal loads, and the material is elastic. The curvature of the post-critical path gives a good indication of the post-buckling stiffening and it can be used to a certain extent to predict post-buckling deformations. Material nonlinearity is one reason that motivates an incremental analysis. Another reason is to evaluate the magnitude of the buckling load for an imperfection sensitive structure. Incremental analysis must include some type of imperfection, in the geometry, material, or alignment of loads.
