• 국제초고층학회논문집
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• 제3권1호
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• pp.21-33
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• 2014

The tied braced frame (TBF) system was developed to achieve uniform seismic inelastic demand along the height of multi-storey eccentrically braced steel frames. A modular tied braced frame (M-TBF) configuration has been recently proposed to reach the same objective while reducing the large axial force demand imposed on the vertical tie members connecting the link beams together in TBFs. M-TBFs may however experience variations in storey drifts at levels where the ties have been removed to form the modules. In this paper, the possibility of reducing the discontinuity in displacement response of a 16-storey M-TBF structure by introducing energy dissipating (ED) devices between the modules is examined. Two M-TBF configurations are investigated: an M-TBF with two 8-storey modules and an M-TBF with four 4-storey modules. Three types of ED devices are studied: friction dampers (FD), buckling restrained bracing (BRB) members and self-centering energy dissipative (SCED) members. The ED devices were sized such that no additional force demand was imposed on the discontinuous tie members. Nonlinear response history analysis showed that all three ED systems can be used to reduce discontinuities in storey drifts of M-TBFs. The BRB members experienced the smallest peak deformations whereas minimum residual deformations were obtained with the SCED devices.

• Earthquakes and Structures
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• 제6권5호
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• pp.561-580
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• 2014

After strong earthquakes conventional frames used worldwide in multi - story steel buildings (e.g. moment resisting frames) are not well positioned according to reparability. Two innovative systems for seismic resistant steel frames incorporated with dissipative fuses were developed within the European Research Program "FUSEIS" (Vayas et al. 2013). The first, FUSEIS1, resembles a vertical Vierendeel beam and is composed of two closely spaced strong columns rigidly connected to multiple beams. In the second system, FUSEIS2, a discontinuity is introduced in the composite beams of a moment resisting frame and the dissipative devices are steel plates connecting the two parts. The FUSEIS system is able to dissipate energy by means of inelastic deformations in the fuses and combines ductility and architectural transparency with stiffness. In case of strong earthquakes damage concentrates only in the fuses which behave as self-centering systems able to return the structure to its initial undeformed shape. Repair work after such an event is limited only to replacing the fuses. Experimental and numerical investigations were performed to study the response of the fuses system. Code relevant design rules for the seismic design of frames with dissipative FUSEIS and practical recommendations on the selection of the appropriate fuses as a function of the most important parameters and member verifications have been formulated and are included in a Design Guide. This article presents the design and performance of building frames with FUSEIS 1-1 based on models calibrated on the experimental results.

• Earthquakes and Structures
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• 제16권5호
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• pp.589-599
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• 2019

Conventional buckling restrained braces used in concentrically braced frames are expected to yield in both tension and compression without major degradation of capacity under severe seismic ground motions. One of the weakness points of a standard buckling restrained braced frame is the low post-yield stiffness and thus large residual deformation under moderate to severe ground motions. This phenomenon can be attributed to low post-yield stiffness of core member in a BRB. This paper introduces a multi-core buckling restrained brace. The multi-core term arises from the use of more than one core component with different steel materials, including high-performance steel (HPS-70W) and stainless steel (304L) with high strain hardening properties. Nonlinear dynamic time history analyses were conducted on variety of diagonally braced frames with different heights, in order to compare the seismic performance of regular and multi-core buckling restrained braced frames. The results exhibited that the proposed multi-core buckling restrained braces reduce inter-story and especially residual drift demands in BRBFs. In addition, the results of seismic fragility analysis designated that the probability of exceedance of residual drifts in multi-core buckling restrained braced frames is significantly lower in comparison to standard BRBFs.

• 한국철학논집
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• 제32호
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• pp.161-183
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• 2011

성호(星湖) 이익(李瀷)의 학문은 포괄적이면서도 회의(懷疑)를 통한 자득(自得)을 중시한다. 그의 학문태도는 성호학파(星湖學派) 가운데에서도 모범적이었으며, 그의 제자들은 그를 본받기 위해 노력하였다. 성호학(星湖學)의 위대성은 그의 직후 바로 성호학파(星湖學派)가 성립됨으로써 드러났다. 성호(星湖)는 "주역(周易)"의 육화(六?)이 내괘(內卦)와 외괘(外卦)로 나뉘어 서로 보아야 한다고 주장한다. 이는 소옹(邵雍)의 방법과 같이 일화(一?)에서 육화(六?)까지가 연결된 것이 아니라 내괘(內卦) 삼화(三?)과 외괘(外卦) 삼화(三?)이 독립된 것임을 밝힌 것이다. 성호(星湖)는 서법(筮法)과 변효(變爻)에 있어서도 주자(朱子)의 서법(筮法)이나 "역학계몽(易學啓蒙)" "고변점(考變占)"에 대해 의문을 제기한 것이 많다. 서법(筮法)에서는 주자(朱子)의 "서의(筮儀)"와는 다른 서법(筮法)을 제시함으로써 후에 다산(茶山)이 새로운 서법(筮法)인 '시괘법(蓍卦法)'을 제시하는데 일조한다. 성호(星湖)의 역학(易學)은 획기적으로 다름을 주장한 것은 아니다. 회의(懷疑)를 통한 자득(自得)이라는 그의 목표아래에서 이루어진 것이다. "시괘고(蓍卦攷)" 역시 마찬가지이다. 성호(星湖)의 역학(易學)은 후대에 다산(茶山)의 역학(易學)을 형성하는데 지대한 공헌을 했다고 하겠다.