Numerical analysis on seismic performance of corner fitting connection in modular steel building

In modular steel building (MSB), connection is a critical part in the structural behavior and ability of load transferring. Previous MSB joints mainly use inter-connection plate or plug-in device, which ignore practical difficulties to hoist and install the modular unit. Therefore, this paper proposed an innovative corner-fitting connection, which is fully prefabricated and liftable. The seismic performance of the novel connection was analyzed by using finite element (FE) software ABAQUS. Numerical study of the novel joint was based on Simplified FE model and Detailed FE model. The developed FE model was verified by comparing with the test results of innovative connections in the previous references. The Simplified model for the joint was developed by using springs to connect the components. Five quasi-static cyclic loading FE analysis were performed on the innovative MSB connection to explore its load transferring capacity and seismic behavior. Results showed that weakening at the beam end can transfer the plastic hinge to the weakened position with little effect on the overall strength. The developed Simplified model can accurately predict the load-displacement curve and Von-mises stress of the joint. With these results, the cyclic response can be incorporated into the Simplified global model by defining the stiffness and dashpot coefficient of the spring. This paper proposed an engineering practical joint and Simplified FE model for seismic analysis of MSB, which is useful for the rapid development of this promising construction method.

Automated summary

In this paper, an innovative corner-fitting connection for modular steel building was proposed, and its seismic performance was analyzed using finite element software. A Simplified FE model was developed to accurately predict load-displacement curve and Von-mises stress of the joint, showing that weakening at the beam end can transfer the plastic hinge to the weakened position with little effect on the overall strength.