Development of a new hybrid damper for steel bracing systems


Tezin Türü: Doktora

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, İnşaat Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2017

Öğrenci: NEFIZE SABAHATIN SHABAN

Danışman: ALP CANER

Özet:

A new hybrid energy dissipation device named as “Backbone Damper” is introduced. The device assembly is composed of two main components: a viscoelastic (VE) unit and an internal displacement amplification mechanism. Energy dissipation is generated through deformations of the VE unit and friction within the mechanism. The mechanism is designed to remain elastic. The effectiveness of the device is verified through numerical simulations of tests of full-size prototypes. A comprehensive three-dimensional solid model of the device is developed to produce the parts of the assembly. The manufactured prototypes are tested under reversed sinusoidal cycles of displacement inputs over a range of frequencies and displacements. The test results evidence a promising device with significant energy dissipation capacity and stable behavior. Prototype tests are used to monitor the device response under different dynamic motions to quantify the design parameters of expected prevalent effect on the Backbone damper performance. vi The device demonstrates a stable hysteretic performance, satisfactory energy dissipation capacity and no damage after 100 cycles of reversed loading. Neither strength nor stiffness degradation are observed in the device performance. Numerical simulations are performed to monitor some of the parameters that are not measured during tests. To this aim, detailed three-dimensional numerical models of a prototype are developed in ABAQUS finite element analysis software. The numerical model is verified against the test results of the device. The test results are also studied to analyze the device behavior and provide estimates for the upper and lower bound values of device modelling parameters. Finally, the response of five buildings equipped with Backbone dampers under an ensemble of strong ground motions is analyzed. A significant improvement of structural response is recorded. The final aim and contribution of the research can be divided in three modules: (1) introduction of a new patented passive energy dissipation device; (2) assessment of its performance and (3) setting design parameters to control its response.