Mechanical model for seismic nonlinear behavior of rubber bearings with end-rotation in highway bridges. (January 2023)

• Record Type: Journal Article
• Authors: Pishgahi, Farnoush; Taghikhany, Touraj
• Is Part Of: Structures. Volume 47(2023)
• Page Start: 875
• Page End: 890
• Publication Date: 2023-01
• Subjects: Elastomeric isolation bearing -- End-rotation -- Macro modeling -- Horizontal stiffness -- Rotational stiffness; Structural engineering -- Periodicals; 624.1
• DOI: 10.1016/j.istruc.2022.11.081
• Languages: English
• ISSNs: 2352-0124

Abstract

Abstract: Rubber bearings in seismic isolated structures are mainly modeled by combination of shear and axial springs. However, the placed isolators under large girders or tall piers are faced with considerable end-rotation which affects their seismic performance. To date, some studies have tried to simulate this effect in bearings with linear elastic behavior. Nevertheless, these models are not proper for high damping elastomeric bearings (HRBs) or lead rubber bearings (LRBs) with nonlinear behavior. In this regard, the present study introduces an improved two-dimensional mechanical model to simulate the interaction between nonlinear shear deformation and end-rotation. The model is verified by previous experimental studies. Later, a sensitivity analysis is conducted by various axial and shear loads with end-rotation to investigate the coupling behavior in HRBs or LRBs. The results indicate that increasing the axial load and shear deformation have a reverse effect on rotational stiffness. Furthermore, end rotation does not have a remarkable effect on critical displacement, however, has a significant impact on the shear force. Moreover, Compressive and shear forces can alter the initial rotational stiffness of the elastomeric bearings.