Behaviour Study of Steel Building System using Different Connection

Abstract

In reality, all beam-to-column connections are considered to be rigid or simple when analysing and designing steel frames. Every realistic beam-to-column connection has some rotational stiffness, ranging from completely rigid to ideally pinned. As a result, SR modelling of connections is more realistic. Assuming that the connections are rigid or perfectly pinned makes it much easier to design and analysis framed structures. As a result, estimating whether the connections are rigid, SR, or pinned is advantageous and practical. The behaviour of the frames at the serviceability and ultimate-limit states should be used to classify the connections. The primary index factors that influence the M-θ properties of connections are stiffness, strength, and rotational capacity. The classification systems for connections by Bjorhovde et al., Eurocode 3, and AISC360-16 are discussed in the present study. In the study, the Frye-Morris Polynomial Model was used to compare the behaviour of the eight types of connections suggested by IS 800:2007. A two-story, one-bay steel frame was used as an example. It was found that the SWA connection is flexible, while the T-stub connection is rigid, and all the other connections are somewhere in between.

In ABAQUS, a 3-D FEM is generated to investigate the impact of various parameters on the behaviour of FEP steel connection under monotonic loading. The suggested model takes into account material and geometrical non-linearities, contact between adjoining surfaces, as well as the pretension force on the bolts. The experimental findings of J.R. Ostrander were utilised to calibrate the finite element results. Comparisons of experimental data with those generated by the present finite element model reveal that the current numerical model can accurately predict and describe the behavior of bolted end-plates.

Connection stiffness features a considerable effect on forces developed within the frame members, lateral displacements of joints, as well as the base shear of the structure during seismic events. The impacts of the beam-column connection’s SR behaviour on the frame structure’s response are being investigated. The M-θ relationship is an important measure of the connections’ semi-rigidity. The SR connections are modelled as MLP link elements with kinematic hysteresis behaviour in SAP2000. A 5-story steel SMRF is modeled, considering rigid connections as well as SR connections. The performance of x the frame is analysed using pushover analysis and response parameters like time period, lateral displacements, base shear and IDR are compared for rigid and SR connections. The semi-rigidity of the connection was found to increase lateral displacements of the modelled frame. Apart from this, the base shear also decreases in SR frames as compared to rigid frames.

The study also discusses the idea of a hybrid steel frame. A hybrid steel frame combines FR and SR steel connections to create a new lateral resistant steel moment structure. The seismic performance of several alternative patterns and locations of SR connections is studied on the 9-story SAC frame. The NSPA is conducted on the suggested chosen frames. The maximum base shear and displacement are used to assess the frame’s performance. Using this concept, the lateral displacement also decreases along with base shear compared to the original SAC frame. The hybrid frames maximum story drift was determined and compared to the FEMA 356 recommended limits for LS and CP performance, as well as to standard SAC frames without SR connections.