Experimental and numerical investigation of high-strength steel circular columns subjected to fire

摘要

This paper presents an experimental-numerical study on the behaviour of High Strength Steel (HSS) columns at elevated temperature, both on Circular Hollow Sections (CHS) and on a Concrete Filled Tube (CFT). The measured yield strength of the circular sections was in the order of 820 MPa. In detail, three HSS CHS and a HSS CFT were tested under the standard ISO fire with constant eccentric compression applied load. The evolution of temperature and deformation patterns were measured by means of a comprehensive instrumentation made of thermocouples and displacement transducers. Numerical analyses were performed and compared with experimental data by employing stress-strain relationships of carbon steel at elevated temperatures provided by the Eurocodes associated to two different sets of reduction factors: ⅰ) those provided by the Eurocodes valid up to S460 steel grades; and ⅱ) those proposed in the literature and based on tests on HSS.