Analysis of fire induced forces in steel design

Abstract

It is a very well know fact that fire may damage our structures. However, structures are not designed by taking into account its existance. Fire sourced additional loads on structures are neglected. Due to this reason, a fire scenario is carried out in a room of an existing building to observe the neglected forces. Forces occuring in structural members that surround the room are aimed to observe in this study. Besides, critical temperatures are also calculated by benefiting from recently made studies as critical temperature are both used as failure criteria in a fire design and behaviour of induced forces change when they reach critical temperatures. Another important part of this study is that it is hoped to form a guideline to explain behaviour of fire exposed members. To do that, recently made studies about fire engineering in the world were collected and presented in this study. Induced forces are calculated at each time step by using these studies and SAP 2000. In the last part of the study, SAFIR finite element program that is used in obtaining fire sourced forces, stresses and displacements are also used by applying the same parametric fire curve that is used in previous parts. Changes in forces sourced by fire is are also presented at each time step to observe the changes. It is also compared with SAP 2000 program that does not calculate all the fire sourced forces itself and it requires to be supported by hand calculation. Assumptions and simplifications caused both some differences and similarities to occur compared to the previously used finite element program in terms of induced forces. Similarities and differences in these two data and reasons behind these differences are tried to be explained as well.