Efficient non‐linear reanalysis of skeletal structures using combined approximations

Non‐linear reanalysis of large‐scale structures usually involves much computational effort, because the set of non‐linear equations must be solved repeatedly during the solution process. Various approximations that are often used for linear reanalysis are not sufficiently accurate for non‐linear problems. In this study, solution procedures based on the combined approximations approach are developed and compared in terms of efficiency and accuracy. Various path‐independent non‐linear analysis and reanalysis problems are considered, including material non‐linearity, geometric non‐linearity and buckling analysis. Numerical examples demonstrate the effectiveness of the procedures presented. It is shown that in various cases accurate results can be achieved efficiently.