Three dimensional frame element formulation for nonlinear analysis of semi rigid steel structures

Özel, Halil Fırat
Sarıtaş, Afşin
Karakaş, Zafer
In this paper, a force-based three-dimensional frame finite element formulation with spread of inelasticity through the element and localized nonlinear semi-rigid connections is developed. The proposed model utilizes Euler-Bernoulli beam theory assumptions, and adopts fiber discretization of monitored sections along element length and section depth for the spread of inelasticity in order to capture axial force and biaxial bending moment interaction. Defining any type of semi-rigid either linear or nonlinear connection behavior along element length does not necessitate any increase in number of degrees of freedom. The element is modelled with option of capturing nonlinear geometric effects. The proposed element is designated for the biased analysis of steel structures, since considering the presence of beam to column semi-rigid connections through analyses provides true behavior. The formulated element can also consider the presence of any type of connection that may be present in a steel structure; such as beam to column, column base, brace end connections. Specific to this study, moment-rotation response of beam to column connections is implemented for both the strong axis and weak axis bending directions. Numerical examples are considered to verify the results obtained from the developed finite element models with regards to other available structural analysis programs.
Citation Formats
H. F. Özel, A. Sarıtaş, and Z. Karakaş, “Three dimensional frame element formulation for nonlinear analysis of semi rigid steel structures,” presented at the 12th International Congress on Advances in Civil Engineering (21 - 23 Eylül 2016), İstanbul, Türkiye, 2016, Accessed: 00, 2021. [Online]. Available: