Sequentially linear versus nonlinear analysis of RC structures

摘要

Purpose - The purpose of this paper is to review recent advances and current issues in the realm of sequentially linear analysis. Design/methodology/approach Sequentially linear analysis is an alternative to non-linear finite element analysis of structures when bifurcation, snap-back or divergence problems arise. The incremental-iterative procedure, adopted in nonlinear finite element analysis, is replaced by a sequence of scaled linear finite element analyses with decreasing secant stiffness, corresponding to local damage increments. The focus is on reinforced concrete structures, where multiple cracks initiate and compete to survive. Findings - Compared to nonlinear smeared crack models in incremental-iterative settings, the sequentially linear model is shown to be robust and effective in predicting localizations, crack spacing and crack width as well as brittle shear behavior. To date, sequentially linear analysis has not been devised with a proper crack closing algorithm. Besides, of utmost importance for many practical applications, sequentially linear analysis requires an improvement of the algorithm to deal with non-proportional loadings. Originality/value - This article gives an up-to-date research overview on the applicability of sequentially linear analysis. For the issue of non-proportional loading, it indicates solution directions.