Location

London

Event Website

http://www.csce2016.ca/

Description

A load deformation hysteresis model has been developed for the piston based self-centering (PBSC) bracing system. This bracing system utilizes shaft-piston mechanism for transferring load to its core energy dissipating elements, which are made of Nickel Titanium alloy (NiTinol) bars. These bars provide the brace its strength as well as the self-centering capability. Although in theory, the NiTinol based shape memory alloy bars are supposed to come back to their original shape after large nonlinear deformations, in reality, they experience residual deformation. The hysteresis models, which are currently available for capturing the behavior of self-centering systems, are known as flag shaped hysteresis. Unfortunately, these flag shaped hysteresis models cannot capture residual deformation. In order to solve this issue a novel hysteresis model has been developed for the PBSC bracing system. This model will enable researchers to capture the PBSC brace behavior in detail during quasi-static and dynamic time history analysis. This hysteresis model is developed using the results of nonlinear static analysis in MATLAB. The resultant plots were thoroughly examined to determine loading/unloading rules. These rules were coded and implemented in the S-FRAME software’s nonlinear analysis solver. A building frame model was built with PBSC bracing system and it was tested using ten earthquake records scaled to Vancouver soil class “C” response spectrum. It was observed that the PBSC brace has an excellent re-centering capability.


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Jun 1st, 12:00 AM Jun 4th, 12:00 AM

STR-978: A HYSTERESIS MODEL FOR THE PISTON-BASED SELF-CENTERING BRACING SYSTEM CONSIDERING RESIDUAL DEFORMATION

London

A load deformation hysteresis model has been developed for the piston based self-centering (PBSC) bracing system. This bracing system utilizes shaft-piston mechanism for transferring load to its core energy dissipating elements, which are made of Nickel Titanium alloy (NiTinol) bars. These bars provide the brace its strength as well as the self-centering capability. Although in theory, the NiTinol based shape memory alloy bars are supposed to come back to their original shape after large nonlinear deformations, in reality, they experience residual deformation. The hysteresis models, which are currently available for capturing the behavior of self-centering systems, are known as flag shaped hysteresis. Unfortunately, these flag shaped hysteresis models cannot capture residual deformation. In order to solve this issue a novel hysteresis model has been developed for the PBSC bracing system. This model will enable researchers to capture the PBSC brace behavior in detail during quasi-static and dynamic time history analysis. This hysteresis model is developed using the results of nonlinear static analysis in MATLAB. The resultant plots were thoroughly examined to determine loading/unloading rules. These rules were coded and implemented in the S-FRAME software’s nonlinear analysis solver. A building frame model was built with PBSC bracing system and it was tested using ten earthquake records scaled to Vancouver soil class “C” response spectrum. It was observed that the PBSC brace has an excellent re-centering capability.

http://ir.lib.uwo.ca/csce2016/London/Structural/108