Redundancy of a mid-rise CFS composite shear wall building based on seismic response sensitivity analysis

Abstract

The redundancy characteristics of a mid-rise CFS composite shear wall building are investigated in this paper taking the basis of the response-based sensitivity methodology (RBSM), and the redundancy results are used to identify the weakness and to reveal the collapse mechanism of the building. Firstly, the sensitivity of the energy dissipation to the elastic modulus of the CFS members and to the stiffness of the equivalent members of the composite shear walls are used as the redundancy indexes for the CFS members and the composite shear walls, respectively. Then the “stacked-type” element modelling method is proposed in this paper because of the RBSM cannot be directly implemented for the CFS buildings according to the current numerical tools. The Two-node link elements and the Nonlinear beam column elements are used to input the hysteretic parameters of the CFS shear walls and the sensitivity parameters, respectively. The classical structural dynamical theory is also used to prove the feasibility of the proposed method in theoretically. Lastly, to verify the redundancy results calculated by the proposed method, a 5-story CFS composite shear wall building was designed and tested by the authors. The results show that the identified components with lowest redundancy are same with the failed components of the test model, indicating that the redundancy could effectively predict and identify the weakness and key components of the CFS composite shear wall system, and it could represent the importance of the components in the CFS structures. The components with lowest redundancy are more easily failed subjected to the earthquake loads, which are needed to be paying attention for the structural design and the collapse mechanism analysis of the CFS structures.