Ultimate analysis of steel structures based on fiber hinge model and time-varying structure theory

Abstract

Oversize deformations and local damages may occur in steel structures due to inappropriate design, inadequacy of construction, improper uses and some other factors. Such damages could produce serious safety problems and shorten the service life of the structures. We proposed in this paper an effective and accurate method for analyzing the ultimate bearing capacity of steel framework based on the fiber hinge model and time-varying structure theory. A detailed study was conducted to investigate a cantilever column with I shaped cross section. The effects of cross section division and fiber hinge unit length on computation accuracy were investigated using SAP2000 finite element software. The proposed method was then applied to a real-life engineering problem, in which the steel structure of a mechanical building was gradually damaged under the action of uneven foundation settlement. The detailed information was obtained for the whole structural damage process as well as for the structural improvements after reinforcement. The results presented in this paper provided valuable information for strengthening of the damaged structures that are usually difficult to obtain in field detection, as well as the critical information for evaluating the structure conditions. In addition, the results in this paper could also provide useful information for safety assessment of new constructions.