EFFECT OF THE MODELLING TECHNIQUE AND THE RATIO OF ADJACENT SPANS ON THE Negative MOMENT OVER COLUMNS IN FLAT SLABS

In this research, several techniques for modeling columns in finite element analysis of flat slabs were explored. A flat slab consisting of 3 spans in the X-direction and 2 spans m the Y-direction was analyzed using the SAP2000 finite element program. A parametric study was conducted to investigate the effect of the column modeling technique on the negative moment over the columns. For each modeling technique the lengths of adjacent spans were varied to study the effect of this variation on the values of the negative moments over the columns. It was noticed that there was a considerable variation between the results obtained using different techniques especially in cases were the difference in adjacent spans was large. Based on these results, guidelines for choosing a finite elements modeling technique for columns in flat slabs are proposed.