| PaperNO | Paper / Abstract |
|
SE7-003
16:10
|
16:30
|
STUDY ON THE PERFORMANCE OF REPLACEABLE LINK ON SEISMIC RESISTANT STEEL STRUCTURES
Steel structures are expected to perform satisfactorily under seismic loads due to their ductile material nature, with yielding provides ductility and energy dissipating mechanism. Damage related to yielding leads to the need for replaceable members, thus promotes the use of replaceable link elements for steel structures. Therefore, an analytical study was conducted to evaluate the performance of seismic resistant steel structures with replaceable links and coupling beams. Two types of structural systems with the different inner column configurations were analyzed, namely concentrically braced frames (CBF) and modified CBF. The length of links were varied between shear links and flexural links. The R factors used in the design were also reviewed. All models were designed using the applicable Indonesian building codes. The analyses performed were pushover analysis and nonlinear time history analysis, and the parameters evaluated were failure mechanism, lateral capacity, ductility, and overall structural performance. Results from pushover analysis reveal that among the models studied, the performance of replaceable links were optimum for structure that used shear links. Time history analysis also concluded that damage was concentrated on links with other elements were not damaged. However, with only small numbers of yielding occurred on the structure, i.e. limited to link elements, the energy dissipation was small compared to the input energy.
Dyah Kusumastuti, Muslinang Moestopo, Erwin Lim
link beam, numerical study, replaceable link, seismic resistant, steel structure
|
|
SE7-011
16:30
|
16:45
|
Seismic performance of damped-outrigger system incorporating buckling-restrained braces
The outrigger system is an effective solution in mitigating seismic responses of core-tube-type tall buildings by mobilizing the axial stiffness of the perimeter columns. The concept of damped-outrigger has been proposed which introduces dampers in the outrigger system to dissipate seismic energy. This study investigates the seismic behavior of a damped-outrigger system incorporating buckling-restrained brace (BRB-outrigger). The outrigger effect combined with the energy dissipation mechanism of the buckling-restrained brace (BRB) effectively reduce the seismic response of the building. This study proposes the methods to evaluate the inelastic seismic response of structures with multiple damped-outriggers based on a spectral analysis (SA) procedure. For the structure with BRB-outriggers, the optimal outrigger elevations, and the relationships between the axial stiffness of the BRB, the axial stiffness of the perimeter column, and the flexural rigidity of the core structure in order to minimize the seismic response are the primary research objectives of this study. Analytical models with building heights of 64m, 128m, 256m, and 384m are used to perform the SA and the nonlinear response history analysis. This study concludes with design suggestion for BRB-outrigger system in preliminary design stages.
Ryota Matsui, Pao-Chun Lin, Toru Takeuchi
buckling-restrained brace, optimal design, outrigger, parametric study, spectral analysis
|
|
SE7-018
16:45
|
17:00
|
STRUCTURAL PERFORMANCE OF STEEL BEAM SYSTEM WITH T- STUB CONNECTION TYPE SEISMIC STEEL DAMPER
In this study, it conducted a cyclic loading test to verify the structural performance of the beam system connections with T-stub connection type steel damper. In the case of target connection detail, the overall shape is similar to T-stub connection detail. the connection system is composed of upper and lower structural connectors, and a beam and a column are fastened by bolting through these connectors. The upper connector of target connection system is a general T-stub with a vertical rib that resist shear forces. The lower connector contains steel slit damper (SSD) and supporting element to help horizontal deformation of the damper against the rotational behavior of the beam-to-column connection. This connection detail was developed in such a way as to be able to complement the deficiencies and retain the advantages of existing connection details with similar structural concept. The major development object of the connection detail is to minimize the damage of the adjacent structural members by effectively concentrating the earthquake energy entering the beam-to-column connections on the damper placed at the beam end. Another development object is to ensure that it can be used as a moment connection detail through evaluation about the strength and stiffness of the proposed connection system. The cyclic loading protocol for beam-to-column connections in accordance with AISC was used for the test method. Test results showed that the proposed connection detail can be effectively reduced the damage of the beams and columns through proactive plastic deformation of the damper. In addition, in the case of specimens designed to have a damper to beam yield strength ratio of 0.6, it was possible to secure the strength equal to or greater than the full plastic moment of the beam and realize rigid connection. Thus, the proposed connection detail is judged to be used as moment resistance connection detail.
Hae-Yong Park, Sang-Hoon Oh
Connection, cyclic loading test, damper, Performance, Plastic deformation
|
|
SE7-020
17:00
|
17:15
|
DESIGN AND APPLICATION OF SBRB FRAMES FOR STEEL TALL BUILDINGS IN TAIWAN: BRACE ORIENTATION AND CONNECTION
In recent years, buckling-restrained braces (BRB) were regarded as an efficient lateral resisting element and energy dissipated devices of building design in Taiwan. This paper presents several applications of BRB framed building cases. First, several BRB frame design cases and common types of BRBs in Taiwan are introduced. In addition, the development histories of BRB cross sections and restraining members are reviewed in this paper. Second, the presence of brace element often interfere with architectural features, and several connections were discussed in order to fit architectural demands. Different BRB cross sections were compared in real design cases. And the concentric and eccentric BRB frames are also compared in different architecture layouts. Different brace-gusset connections are introduced from former researches. The local behaviors of different brace connections were simulated using finite element method corresponding to practical design cases. Finally, the global responses of different BRB framed buildings are presented in this paper. Different cases designed using Taiwan building code were compared by using Push-Over Analysis. Observations from pushover curves show the global behavior of BRB frames designed using Taiwan building code.
Jia Hau Liu
BRB, buckling-restrained brace, Dual Gusset Plate, finite element analysis, pushover analysis
|
|
SE7-023
17:15
|
17:30
|
THE SEISMIC PERFORMANCE OF DEVELOPED HCE STRUCTURES FOR PREFABRICATED SHEAR WALLS
In the earthquake, the cyclic shear deformation between two prefabricated walls will occur and the horizontal connection will come to fracture resulting in collapse of the structure. In order to improve the energy dissipation capacity of prefabricated structures and prevent the structure from overall collapse in the super-large earthquake, a horizontal connecting and energy dissipating structure (HCE) is developed, which could be employed for horizontal connection of the prefabricated shear wall system. The HCE structure consists of the external replaceable energy dissipating zone (ED) mainly used to dissipate the seismic energy and the internal stiffness lifting zone (SL) for enhancing the load carrying capacity. By the predicted displacement threshold control device, the ED made in bolted low-yield point steel plates could firstly dissipate the energy which could be replaced after damage, the SL would delay bearing load and the loading-displacement curves of the HCE structure would exhibit “double-step” characteristics. In order to investigate the hysteretic behaviour HCE structures, detailed finite element models are validated and established in software ABAQUS and parametric analysis on aspect ratio, the shape of the steel plate in ED and the displacement threshold in SL the is made. The numerical results, such as hysteresis curves, skeleton curves, deformation behaviour, and failure modes, are used to evaluate the seismic performance of the HCE structure. It is found that the HCE structures depict high energy dissipating ability and its bearing capacity could be obtained again after the yielding of ED.
Limeng Zhu, Lingmao Kong, Chunwei Zhang
“Double-step” characteristics, seismic performance, Steel horizontal connection, Stiffness lifting
|