含中等韌性箱型鋼柱七層樓鋼造二元構架系統之複合模擬子結構試驗
Other Title
Hybrid Simulation of a Steel Seven-Story Dual System With Measured Buckling-Induced First-Story Box Column Shortening in Subassemblage Tests
Journal
結構工程
Journal Volume
39
Journal Issue
2
Start Page
39
End Page
67
ISSN
1021-7878
Date Issued
2024-06
Author(s)
Abstract
本文利用複合模擬實驗（hybrid simulation, HS）技術，探討一樓銲接箱型鋼柱在軸力及彎矩共同作用下局部挫屈導致鋼柱縮短對整體建築構架耐震行為影響。本研究將HS應用於一個七層樓鋼造二元構架的數值模型及一實尺寸試體子構架，探討在近斷層地震力作用下的反應。該實尺寸試體為包含中等韌性銲接箱型鋼柱及與其相連之I型梁的子構架。當試體受到軸力和側向位移時，柱發生撓曲挫屈，柱底產生局部挫屈，導致柱縮短。為了模擬此現象，本研究透過在數值模型中施加一組虛擬等效力以強制達成實驗和數值模型間之位移諧和。在實驗控制上，本研究使用一個四自由度（degree of freedom, DOF）的混合控制模式（三位移和一力量控制）進行加載，使得能以簡化之實驗配置模擬子構架試體複雜之邊界條件。在HS過程中，一樓中間柱的縮短量乃於實驗中實際量測試體反應，而一樓外柱的縮短量則是利用軟體ABAQUS根據以往鋼柱實驗資料比對事前分析而得。實驗結果證實本研究所提出的控制和建模方法之有效性，能將實驗實際量測及ABAQUS分析所得之柱垂直位移成功納入HS的數值歷時分析中，從而更真實地模擬柱縮短對整體構架的影響。此外，中等韌性銲接箱型鋼柱在近斷層地震荷載下表現出良好的耐震行為，驗證AISC 341高等韌性鋼柱寬厚比限制太過保守。
This paper presents a series of hybrid simulation (HS) conducted on full-scale steel beam-column connection subassemblages to study the seismic responses of a two-dimensional steel dual frame, considering first-story steel column shortening caused by local or global buckling during the seismic events. A seven-story two-bay dual frame system is composed of a special moment frame (SMF) and a buckling-restrained braced frame (BRBF) using built-up box columns. The experimental substructure consists of a full-scale interior column and beam cruciform subassemblage, including a moderately ductile first-story built-up box column and two I-shaped beams. Under combined axial and lateral loads, local buckling can occur near the column base, resulting in column shortening. The specimen is loaded through a four degree of freedom (DOF) mixed-mode control (three displacement- and one force-control) actuation system that simplifies the laboratory loading conditions given the complex boundary conditions of the frame structure. To account for column shortening in the HS, a new approach is applied to enforce compatible displacements between the experiment and numerical model. With the column axial load in force control and column shortening, a set of fictitious equivalent forces is applied to columns in the numerical model to achieve compatible displacements. Shortening of two exterior columns in the model is simulated through finite element analysis using the computer program ABAQUS. The test results confirm that the proposed modeling and control methods could successfully integrate the information available in the laboratory and ABAQUS simulation into the HS, resulting in a more realistic frame response that captures the effect of column shortening in the analysis. The moderately ductile built-up box column is also verified to perform well in near-fault earthquake loadings.
Subjects
複合模擬
中等韌性銲接箱型鋼柱
挫屈
力量控制
位移諧和
hybrid simulation
moderately ductile built up box column
buckling
forced control
displacement compatibility
Type
journal article