ABSTRACT
All structures deflect under loading. The effect of this loading acting on the deformed geometry of the structure creates what is referred to as the second-order effects. Second-order effects are usually detrimental to the strength and stability of the structure, and for safety reasons these effects should be considered in design. The consideration of second-order effects requires an analyst to perform nonlinear analysis; however, in general, rigorous nonlinear analyses are tedious and time-consuming. For cases in which accurate solutions are not required, it may be more advantageous to resort to simplified techniques by which secondorder effects are considered in an approximate manner. For example, in designing a structure, it is often necessary to iterate the analysis/design sequence several times before a final design can be made. The structure is re-analyzed for each new design. Normally, accurate analysis results are not required for improving a current design during the analysis/design cycle. The use of approximate secondorder analysis techniques allows an analyst to perform the re-analysis in a simple and expeditious manner.
