Behavior of Rectangular Concrete Filled Steel Tubular Columns Subjected to Biaxial Eccentricity

Abstract

With the advancement of construction technology, the focus has shifted from building a structure that can withstand specific stress to building structures by utilizing the materials to their maximum load capacity. This shifting of focus has made it possible to build lighter structures by eliminating and improving old materials’ drawbacks. Concrete filled steel tubular columns are the results of the advancement in construction technology. Their stiffness makes them suitable for earthquake resistant structures, and the steel encasement helps to get rid of the need for formwork, which is vital in saving money and speed of construction. Nowadays, we see rapid growth in the construction sector of Ethiopia. Many industrial zones are being constructed all over the country. Most of these industrial zones use steel-concrete composite materials because of the ease and speed of construction. Furthermore, a lot of halls and churches are using composite construction. Therefore this would be a great time to look at and research composite materials. In this research, three types of rectangular concrete-filled steel tubular columns subjected to different biaxial eccentricity values are studied. The parameters investigated are; height and area of concrete of columns, yield strength of steel, steel thickness, and eccentric distance. A total of 72 different column specimen combinations are studied using the Finite Element Analysis software ABAQUS. A total of 150 graphs showing the load versus deformation property of individual columns, along with graphs that compare different load versus deformation values, are presented in this research. The deformation values which mark the columns’ elastic limit range from 2mm-4mm and that of concentrated load varies from 3000KN – 9000KN. The results obtained show that steel yield strength, concrete area, and thickness of steel are directly proportional to the strength of RCFST columns and height of columns is inversely proportional to their strength. It is also found out that the performance of RCFST columns decreases the further the load moves away from the center of the columns,