Dynamic Response of Inter-story Isolated High-rise Building Subjected to Wind Flow

The effects of base and inter-story isolation devices on the dynamic response of a high-rise building under wind flow were investigated in this study. In this regard, dynamic fluid-high rise structure interaction due to wind load was studied using Computational Fluid Dynamics (CFD) by ABAQUS software. The model was divided into two main parts including building with isolation system and wind domain (Eulerian domain) which simulated using Finite Element Method (FEM) and CFD, respectively. In the CFD, the k-epsilon renormalization group RNG turbulence model was considered. The Lead Rubber Bearing (LRB) isolation device was simulated in this study. Four types of buildings including fixed-base, base-isolated, base and 10th story isolated and base and 20th story isolated buildings were developed in this study. All components of the building as well as LRB device were simulated as three-dimensional solid parts. Each part of the model was tied to corresponding components using Tie-Constraint tool. According to previous studies, a proper material behavior was assigned to each component of the model. The Dynamic-Implicit step was used to analysis the FEM model. Both CFD and FEM models were interacted using Fluid–Structure Co-simulation boundary. The buildings were subjected to the wind flow with mean speeds 75, 100 and 125 km/h. Through a parametric study, the effects of base and inter-story isolation devices on the lateral displacement of building, story drift ratio, variation of shear stress along the height of the building, base shear force, wind streamlines, wind pressure distribution and wind velocity distribution were investigated. The key findings indicate that although the base and inter-story isolation devices have no significant effects on the wind velocity and wind pressure around the high-rise building, they decrease the drift ratio of upper stories of the building about 14 to 21 percent for wind speed of 75 km/h. Moreover, this reduction was about 2.9 to 3.7 percent at wind speed of 100 km/h. In addition, base and inter-story isolation devices decrease shear stress along the building height and the base shear force by about 27 to 29.5 percent at 75 km/h wind speed, and 2 to 26.5 percent at wind speed of 125 km/h.