Liu, Xu, and Li, 2019
A new steel plate shear wall system with self centering energy dissipation bracing (SPSW - SCEDB) system was proposed in order to increase the energy dissipation and self centering capacity of a building by concentrating these properties into a replaceable unit. A 1:3 scale single bay single story specimen was fabricated in order to observe the seismic performance of the system, and it exhibited flag shaped hysteretic responses while increasing the energy dissipation and self centering of the specimen.
System Concept
The steel plate shear wall self centering energy dissipation bracing system (SPSW - SCEDB) includes steel plate to improve the ductility of the structure and aid in energy dissipation, which is bolted only to horizontal boundary elements (HBE) in order to provide energy dissipation to the structure, along with pre-pressed spring self-centering energy dissipation braces (PS-SCED) in order to provide a greater self centering ability and increase the energy dissipation capacity of the structure. In order to resist lateral structures, the SPSW-SCEDB is bolted only to the upper and lower HBE’s, as well as two PS-SCED systems that are located symmetrically on either side of the SPSW.
The structure is intended to dissipate lateral loads through energy dissipation that occurs when the SPSW system yields and deforms, thus concentrating the permanent deformation of the structure into replaceable components, which will both increase energy dissipation capacity of the structure and reduce reparation costs post-earthquake. Furthermore, the repairability of the structure is further increased due to the self centering properties of the PS-SCED system, which is comprised of an inner and outer tube which move when the activation strength is exceeded by the external force, thereby providing a self centering force to the system and exhibiting flag shaped hysteretic responses.
Experimental Study, Results, and Discussion
The study within this paper consisted of a 1:3 scale single bay, single story system of the SPSW-SCEDB system which was fabricated in order to understand the system’s response to lateral loading and seismic conditions. Displacement meters and strain gauges were utilized in order to monitor the deformation of the structure due to strain, which was measured using a force transductor. Both in plane and out of plane deformations were monitored throughout the structure.
First, cyclic loading was performed on the individual elements of the SPSW and the PS-SCED systems in order to verify their individual hysteretic behaviors. Following the tests on the individual components of the system, a cyclic loading test was performed on the full 1:3 scale SPSW-SCEDB system. The system as a whole exhibited a flag shaped hysteretic curve due to the cyclic loading, however the activation forces of the PS-SCED system was larger than expected, meaning that it contributed less to the overall self-centering capacity of the system. Overall, the system remained ductile and had high energy dissipation due to the SPSW system, while still having full self centering capacity due to a maximum residual drift of 0.16%.
Reference
Liu, J., Xu, L., Li, Z. (2020). “Development and experimental validation of a steel plate shear wall with self-centering energy dissipation braces,” Thin Walled Structures, 148, pp 22.