• 한국생산제조학회지
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• 제21권2호
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• pp.214-220
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• 2012

About 12 million people of the mobility handicapped were increased by the end of 2009 year. Universal design concept has been implemented in developed countries. Since 2004 low-floor buses are in Korea. In this study, there is no provision for mobility handicapped and small buses that can be comfortable riding car ramp design presented. The gate of a small buses lowered height of 200mm. Install the ramp in the center of the ramp by an air cylinder moves from side to side. The slope of the ramp was controlled by a hinge. Air cylinder thin type applicable in the narrow space of the slide cylinder was used.

• Structural Engineering and Mechanics
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• 제2권1호
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• pp.81-94
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• 1994

It is well recognized that structures designed to resist strong ground motions should be able to withstand substantial inelastic deformations. A simple procedure has been developed in this paper to monitor the dynamic earthquake response (time-history analysis) of both steel and concrete multistorey buildings in the inelastic range. The building is treated as a shear beam model with three degrees of freedom per floor. The entire analysis has been programmed to run on a microcomputer and can output time histories of displacements, velocities, accelerations and member internal forces at any desired location. A record of plastic hinge formation and restoration to elastic state is also provided. Such information can be used in aseismic analysis and design of multistorey buildings so as to control the damage and optimize their performance.

• Computers and Concrete
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• 제2권2호
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• pp.147-164
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• 2005

This paper summarizes an experimental study on the seismic behavior of lower stories of a mid-rise reinforced concrete frame building. Two reinforced concrete frames with two stories and one span were tested and each frame represents lower two stories of an 11-story RC frame building. Both frames were designed in accordance with Japanese design guidelines and were identical except in the variation of axial force. The tests demonstrated that the overall load-displacement relations of the two frames were nearly the same and the first-story column shear was closely related to the column axial load. The columns and beams elongated during both of the tests, with the second-floor beam elongation exceeding 1.5% of the beam clear span length. The frame with higher axial loads developed more cracks that the frame under moderate axial load.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2001년도 가을 학술발표회 논문집
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• pp.443-450
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• 2001

The Mixed building structures can be divided into three partition, namely, upper wall, lower frame, and transfer system which link two partitions. The purpose of this study is to investigate the nonlinear response characteristics of structures, as the stories of lower frame of mixed building structures changes. The recorded earthquake ground motions of EI Centro 1940 NS is adopted, and the maximum ground accelerations are adjusted to 55ga1, 110ga1, 220ga1, 330ga1. The conclusions of this study are the following. 1) The responses of model that the story of lower frame is one were different from those of other models. 2) The process of ductility hinge occurrence of member was ends of coupling beam of upper wall and ends of beam of lower frame in 55ga1, bases of shear wall on pit floor in 110ga1, and bases of column of 1F in 220ga1.

• Earthquakes and Structures
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• 제17권3호
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• pp.283-295
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• 2019

During the seismic performance assessment of existing buildings, staircases are generally not taken into account as structural members but as dead load. Staircases, as secondary structural members, not only serve for connecting successive floors but also provide considerable amount of strength and stiffness to the building which can modify its seismic behaviour considerably. In this parametric study, the influence of staircases on the seismic response of substandard RC frame buildings which differ in number of storey and span, presence of staircase and its position has been examined. Modal Analyses and bi-directional Non-Linear Time History Analyses (NLTHA) were conducted to compare several engineering demand parameters (EDPs) such as inter-storey drift ratio (ISDR), floor accelerations, modal properties, member shear forces and plastic hinge distribution. Additionally, short column effect, variation in shear forces of columns that are attached to the staircase slab, failure and deformation in staircase models have also been investigated. As the staircase was considered in the analytical model, a different damage pattern can be developed especially in the structural components close to staircase.

• Earthquakes and Structures
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• 제8권2호
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• pp.463-484
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• 2015

Modern codes for earthquake resistant building design require consideration of the so-called accidental design eccentricity, to account for torsional response caused by several factors not explicitly considered in design. This provision requires that the mass centres in the building floor be moved a certain percentage of the building's dimension (usually 5%) along both the x and y axes and in both positive and negative directions. If one considers also the spatial combinations of the two component motion in a dynamic analysis of the building, the number of required analyses and combinations increases substantially, causing a corresponding work load increase for practicing structural engineers. Another shortcoming of this code provision is that its introduction has been based primarily on elastic results from investigations of oversimplified, hence questionable, one story building models. This problem is addressed in the present paper using four groups of eccentric braced steel buildings, designed in accordance with Eurocodes 3 (steel) and 8 (earthquake design), with and without accidental eccentricities considered. The results indicate that although accidental design eccentricities can lead to somewhat reduced inelastic response demands, the benefit is not significant from a practical point of view. This leads to suggestions that accidental design eccentricities should probably be abolished or perhaps replaced by a simpler and more effective design provision, at least for torsionally stiff buildings that constitute the vast majority of buildings encountered in practice.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1993년도 춘계학술대회논문집
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• pp.1-9
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• 1993

A human gait study is required for the biomechanical design of running shoes. A tow-dimensional dynamic model was developed in order to analyze lower extremity kinematics and loadings at the right ankle, knee, and hip joints. The dynamic model consists of three segments, the upper leg, the lower leg, and the foot. Each segment was assumed to be a rigid body with one or two frictionless hinge joints. The lower extremity motion was assumed to be planar in the sagittal plane. A young male subject was involved in the gait test and his anthropometric data were measured for the calculation of segement mass and moment of inertia. The experimental data were obtained from three trials of walking at 1.2m/s. The foot-floor reaction data were measured from a Kistler force plate. The kinematic data were acquired using a three-dimensional motion measurement system (Expert Vision) with six markers, five of which were placed on the right lower extremity segments and the rest one was attached to the force plate. Based on the model and experimental data for the stance phase of the right foot, the calculated vertical forces reached up to 492, 540, and 561 N at the hip, knee, ankle joints, respectively. The flexion-extension moments reached up to 155, 119, and 33 Nm in magnitude at the corresponding joints.

• Steel and Composite Structures
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• 제41권5호
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• pp.713-730
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• 2021

The seismic performance of rigid steel frames is widely investigated, but that of semi-rigid (SR) steel frames are not studied extensively, especially for near-field earthquakes. In this paper, the performances of five and ten-story steel SR frames having different degrees of semi-rigidity are evaluated at four performance points in the four different deformation states, namely, the elastic, elasto-plastic, plastic, and near collapse states. The performances of the SR frames are measured by the response parameters including the maximum values of the top floor displacement, base shear, inter-story drift ratio, number of plastic hinges, and SRSS of plastic hinge rotations. These response parameters are obtained by the capacity spectrum method (CSM) using pushover analysis. The validity of the response parameters determined by the CSM is evaluated by the results of the nonlinear time history analysis (NLTHA) for both near and far-field earthquakes at different PGA levels, which are consistent with the performance points. Results of the study show that the plastic hinges of SR frame significantly increase in the range of plastic to near-collapse states for both near and far-field earthquakes. The effect of the degree of semi-rigidity is pronounced only at higher degrees of semi-rigidity. The predictions of the CSM are fairly well in comparison to the NLTHA.

• 자원환경지질
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• 제4권1호
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• pp.39-43
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• 1971

한반도(韓半島)는 지형운동(地穀運動)이 없이 안정(安定)한 상태(狀態)에 있는 아시아대륙(大陸)과, 지형운동(地鼓運勤)이 활발(活廢)한 일본열도(日本列鳥)의 사이에 위치(位置)하고 있다. 한반도(韓半島)는 비재적(比載的) 좁은 동서폭(東西幅)을 가지고 있는데도 불구(不拘)하고, 동해안(東海岸)은 융기(隆起), 서해안(西海岸)은 침강현상(沈降現象)을 보여 주고 있다. 그러나 서해안(西海岸)의 침강율(沈降率)을, 지형운동(地鼓運勤)이 거의 없이 안정(安定)한 상태(狀態)의 북미(北美) 동해안(東海岸)의 침강율(沈降率)과 비교(比較)해 보면 한반도(韓半島)의 서해안(西海岸)은 동해안(東海岸)과 함께 서서(徐徐)히, 융기(隆起) 하되, 다만 시차적(示差的) 융기현상(陸起現象)을 보이는 듯 하다. 이러한 융기현상(陸起現象)은 동해안(東海岸)(일본해(日本海))을 따라 전개(展開)하는 현상(現象)이다. 태평양(太平洋) mantle convection이 일본해구(日本海溝)를 따라 아세아대륙(大陸)으로 plunge 하는 데서 발생(發生)하는 압축응력(壓縮應力)에 기인(基因)하고 있을 것 같다. 또한 이러한 strain은 동해(東海) 일대(一帶)의 높은 heat flow에 의(依)해서 가속(加速)될 것 같다. 이와 같이 근세(近世) 한반도(韓半島)의 지형운동(地穀運動)을 해저확장설(海底擴張說) (Sea Floor Spreading Theory)로서 설명(說明)할 수가 있으며, 휴화산(休火山)인 백두산(白頭山)과 한라산(漢筆山)을 한반도(韓半島)가 서진(西進)한 증거(證據)로 간주(看做)할 수도 있다.

• 한국지진공학회논문집
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• 제5권5호
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• pp.73-83
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• 2001

상부벽식-하부골조구조(복합구조)는 상.하부 구조물의 서로 다른 구조형식으로 인해 전이층 부근에서 질량 및 강성의 큰 차이를 보인다. 이러한 복합구조의 특징은 일반적으로 강성, 질량 및 기하학적 수직 비정형성을 갖게 된다. 본 연구에서는 복합구조물의 상부층수가 변화하는 네 가지 해석모델을 선정하여 탄소성 정적 및 동적 해석을 수행하고 해석결과를 통해 구조물의 탄소성 응답특성을 살펴보고자 한다. 본 연구의 결론은 다음과 같다. 1) 탄소성 정적해석에서는 하부골조 구조의 보와기둥의 항복힌지가 상부벽식구조의 층수 변화에 상관없이 전 모델에 걸쳐 비슷한 크기의 설계용 밑면전단력에서 항복이 발생되었고 그 분포 또한 비슷하였다. 그러나 상부벽식구조의 경우 전단벽이 고층화될수록 coupling beam에서 설계용 밑면전단력 V에 대해서도 휨항복한지가 발생되었다. 2) 탄소성 동적해석으로부터는 하부골조의 일부층의 보는 55gal의 작은 지진동에서 소성이 발생되었고 상부벽식구조의 경우 coupling beam과 전이층 상부의 전단벽에서 소성변형이 집중되었다. 3) 탄소성 해석으로부터 상부벽식구조의 층수가 낮아질수록 하부골조구조의 층강성이 상대적으로 줄어들게 되어 하부골조에서 연약층(soft story) 현상이 나타났다.