Validation of Fiber-Based Distributed Plasticity Approach for Steel Bracing Models
Abstract: Nonlinear analysis
approach is not anymore limited only to research purposes, but becoming more
popular as a tool that can be used during design, thanks to the increased
efficiency of computer software and hardware. An accurately calibrated
numerical model may simulate the behaviour of buildings in a quite realistic way,
which helps designers understand better the performance of their structures.
However, the feasibility of the nonlinear analysis approach is limited by the
complexity of the numerical model, and the aim of any researcher or engineer is
to obtain the most useful information in a reasonable amount of time. This
study focuses on the validation of a simplified numerical modelling approach to
simulate the nonlinear behaviour of steel bracings. The paper presents a
comparison between two different modelling approaches; a refined finite element
model using volumetric elements, and fiber-based model using beam elements with
distributed plasticity. The numerical models calibrated with the experimental
result from existing literature, reproduce the behaviour of cold formed square,
and hot rolled open section steel elements under inelastic cyclic loading. The
hysteresis loops obtained from two models show that the accuracy obtained by
simpler fiber-element formulation is quite close to the more refined volumetric
model. Finally, in order to assess the accuracy of the fiber-based modelling
approach to estimate the nonlinear cyclic response of full-scale braced frame
configurations, two real scale frames are analysed, and the results are
compared with the results of the experiments performed on the test frames. In
terms of computation time and accuracy, distributed plasticity model is much
more efficient, and can be a good option to perform nonlinear analysis of
multi-level buildings, which would be quite cumbersome with volumetric
modelling approach. This study has been realized thanks to the research fund
received from European commission with the contract MEAKADO RFSR-CT-2013-00022.
Author: Alper Kanyilmaz
Journal Code: jptsipilgg150035
