Efficient analysis of flat slab structures subjected to lateral loads

The flat slab system has been adopted in many buildings constructed recently due to the advantage of reduced floor heights to meet the economical and architectural demands. Structural engineers commonly use the “equivalent frame method” with equivalent beams proposed by Jacob S. Grossman in practical engineering for the analysis of flat slab structures. However, in many cases, when it is difficult to use the equivalent frame method, it is necessary to use a refined finite element model for an accurate analysis. However, this takes a significant amount of computational time and memory if the entire building structure were to be subdivided into a finer mesh. An efficient analytical method is proposed in this study to obtain accurate results in significantly reduced computational time. The proposed method employs super elements developed using the matrix condensation technique and fictitious beams are used in the development of super elements to enforce the compatibility at the interfaces of super elements. The stiffness degradation due to cracking in the flat slab system considered in the equivalent frame method was taken into account by reducing the modulus of elasticity of floor slabs based on linear elastic finite element analysis in this study. Static and dynamic analyses of example structures were performed and the efficiency and accuracy of the proposed method were verified by comparing the results with those of the refined finite element model and the equivalent frame method.