철탑 사각골조의 풍력 계수 산정에 관한 실험적 연구

신구용,임재섭,황규석,길용식,Shin, Koo-Yong,Lim, Jae-Seob,Hwang, Kyu-Seok,Kil, Yong-Sik 한국강구조학회 2011 韓國鋼構造學會 論文集 Vol.23 No.1

골조로 구성된 철탑의 풍력계수는 구성부재의 단면형상, 충실율 등에 의해 변하며 풍향각에 의해서도 여러 가지 특성이 나타난다. 본 연구에서는 이러한 철탑골조에 대하여 충실율과 풍향각을 변화시키면서 풍동실험을 수행하여 철탑골조에 작용하는 풍력특성을 평가한다. 실험은 먼저 철탑을 구성하고 있는 부재의 특성을 파악하기 위한 기본형상 부재에 대한 실험을 수행하였다. 그리고 철탑 사각골조는 2D와 3D 형태로 기본형에 철탑부재를 추가하는 방법과, 부재크기를 증가시키는 방법으로 충실율을 변화시킨 모형을 제작하였으며, 2D 형상은 풍향각을 0도에서 90도까지, 3D 형상은 풍향각을 0도에서 45도까지 변화시키면서 풍동실험을 수행하였다. 본 연구의 결과인 철탑 사각골조의 풍력계수 특성은 향후 철탑 풍하중 설계의 기초자료로 사용될 것이다. The wind force coefficient of a transmission tower frame shows several characteristics when the section shape, solidity ratio, and wind direction angle are changed. In this study, the wind force characteristics of a transmission tower frame with a basic structure were evaluated using different solidity ratios and wind direction angles in a wind tunnel test. According to the solidity ratio, the size of the structure and the rectangular-frame model of the transmission tower were changed by adding a two-dimensional (2D) or three-dimensional (3D) structure. The transmission tower's rectangular frame was tested by changing the wind direction angle of the 2D-type structure from 0 to $90^{\circ}$ and by changing the wind direction angle of the 3D-type structure from 0 to $45^{\circ}$ Based on the results that were obtained, it can be concluded that the wind force coefficient of a transmission tower frame can be used as preliminary data in deciding the transmission tower's wind load.

고유진동수 조절이 가능한 액체댐퍼의 건물응답 제어실험

김동익,민경원,박지훈,김재건,황규석,길용식,Kim, Dong-Ik,Min, Kyung-Won,Park, Ji-Hun,Kim, Jae-Keon,Hwang, Kyu-Seok,Gil, Yong-Sik 한국전산구조공학회 2012 한국전산구조공학회논문집 Vol.25 No.4

This study deals with the experiments of liquid dampers with multi cells whose vertical tubes are divided into several square columns for easily changing natural frequencies. Shaking table test is performed to verify control effectiveness of the dampers which are installed on a building structure. To design liquid dampers, a 64-story building structure is reduced to a SDOF structure with 1/20 of similitude laws based on acceleration. The structure model is made up to adjust its mass and stiffness easily, with separate mass and drive parts. Mass parts indicate real structure's weights and drive parts indicate real structure's stiffness with springs and LM guides. Manufactured liquid damper has 18 cells and its natural frequency ranges are 0.65Hz to 0.81Hz. Shaking table test is carried out with one way excitation to compare with only accelerations of a large-scale structure and a structure installed with liquid dampers. Control performance of the liquid damper is expressed by the transfer function from shaking table accelerations to the large-scale structure ones. Testing results show that the liquid damper reduced a large-scale structure's response by tuned natural frequencies. 본 연구진은 최근 U자 형태인 액체댐퍼의 수직관을 다수의 셀(사각 기둥)로 나누어 셀 상부를 개폐함에 따라 다양한 고유진동수를 쉽게 재현하는 새로운 멀티셀 액체댐퍼를 제시하였다. 이러한 댐퍼를 1층 건물 모형에 설치하여 진동대 실험을 수행하여 건물응답이 감소되는 것을 검증하였다. 64층의 풍응답인 가속도를 제어할 수 있도록 댐퍼를 설계하기 위하여 건물을 1자유도계로 축소하였다. 가속도 기반 상사비인 1/20를 적용하여 1층 건물 모형과 새로운 댐퍼를 제작하였다. 설계 진동수인 0.65Hz가 구현되도록 모형건물의 질량과 강성을 쉽게 조절할 수 있도록 탈부착식으로 제작하였다. 모형건물은 중량을 부담하는 질량부와 하부에 스프링과 LM guide가 설치된 구동부로 나누어서 제작되었다. 18개의 셀을 가지는 액체댐퍼를 제작하여 고유진동수 조절 범위가 0.65Hz~0.81Hz인 것을 파악하였다. 대형 진동대에 설치한 모형건물의 일방향 가진을 통하여 모형의 응답을 측정하고 모형상부에 멀티셀 액체댐퍼가 설치되었을 경우 모형의 응답을 측정하여 비교하였다. 진동대 가속도를 입력과 모형건물의 가속도를 출력으로 하는 전달함수를 통해 결과를 나타내었다. 예상한 바와 같이 멀티셀 액체댐퍼의 고유진동수를 건물의 진동수에 동조시켰을 경우 건물의 가속도 응답이 감소함을 알 수 있었다.

관형지지물 풍력계수 특성에 관한 실험적 연구

길용식(Gil, Yong-Sik),황규석(Hwang, Kyu-Seok) 대한건축학회 2013 大韓建築學會論文集 : 構造系 Vol.29 No.8

Wind force coefficient of tubular steel pole shows several characteristics when shape of section and angle of wind direction are changed. In this study, wind force characteristics of tubular steel pole are evaluated using different wind speed and angle of wind direction in wind tunnel test. Three types of tubular steel pole was selected for the experiment which were actually used at construction. For each type of model, entire model and cross-section model was made to experiment. The experiment on cross-section model is changing angle of wind direction from zero degrees to thirty degrees and changing of wind speed from 1 m/s to 18 m/s, and entire model is changing angle of wind direction from zero degrees to ninety degrees. From the result, wind force coefficient of tubular steel pole can be used as preliminary data to decide tubular support"s wind load.

고유진동수 조절이 가능한 액체댐퍼 특성연구

길용식(Gil Yong-Sik),황규석(Hwang Kyu-Seok),김재건(Kim Jae-keon),민경원(Min Kyung-Won) 대한건축학회 2011 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.31 No.2(구조계)

In this paper, we evaluate the properties after developing the unique frequency-controlled multi-cell liquid damper. The overall shape of the proposed damper is same with the Liquid Column Vibration Absorber (LCVA). However, in this time, we divided the vertical column of LCVA in a separate cell and the cell can be closed each so that we can change the natural frequency of the damper with the way we control the area of the vertical column. In this way, we could notice the properties of the natural frequencies of the damper through the shaking table tests with the adjusted closed cell number. The usability of the dampers was evaluated after comparing to the natural frequencies of shaking table experiments and the theoretical calculated one.

3차원 복합 산지형의 풍속할증에 관한 연구

길용식(Kil Yong-Sik),황규석(Hwang Kyu-Seok) 대한건축학회 2009 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.29 No.1(구조계)

This study estimated the characteristic of Topographic factors on three dimensional complex hills through the wind tunnel tests. The wind tunnel tests was performed using various hills models which have a slop of 21.80°, that is based on the Korean Building Code (KBC2005). From the results of wind tests, Topographic factors on three dimensional complex hills were calculated at various positions and the ranges of topographic effects were decided. In the characteristics of wind speed-up, the results of wind tests show that the complex hills have difference from the general hills.

수리모형을 이용한 환승제약과 서비스 선택특성을 고려한 고속철도와 지역간철도 서비스의 선로용량배분

서선덕(Suh Sunduck),황규석(Hwang Kyu Seok),송선아(Song Sun Ah),원유나(Won Yu Na) 대한토목학회 2003 대한토목학회 학술대회 Vol.2003 No.10

태양광발전(PV)과 에너지저장장치(ESS)의 지능적 연계를 위한 PMS 구현

민병빈(Byoung-Bin Min),황재창(Jae-Chang Hwang),김준용(Jun-Yong Kim),황규석(Kyu-Seok Hwang),류강열(Kang-Ryul Ryu) 전력전자학회 2020 전력전자학술대회 논문집 Vol.2020 No.8

한우 육질등급에 따른 도체등급 요인, 이화학적 및 관능특성

이종문,최주희,이현경,나재천,김윤호,천동원,서상철,황규석,Lee, Jong-Moon,Choe, Ju-Hui,Lee, Hyeon-Kyeong,Na, Jae-Cheon,Kim, Yuen-Ho,Cheon, Dong-Won,Sea, Sang-Chul,Hwang, Kyu-Seok 한국축산식품학회 2010 한국축산식품학회지 Vol.30 No.3

Analyses were conducted to estimate the effect of quality grade on the carcass characteristics, physico-chemical and sensory traits of Longissimus dorsi in Hanwoo. A total of 42,113 carcasses were selected on the basis of five quality grades (grade $1^{++}$, $1^+$, 1, 2, and 3) and an additional 258 samples of Longissimus dorsi were used to evaluate the beef quality. The increase in quality grade from grade 3 to grade $1^{++}$ was significant (p<0.05) for carcass weight (from 338.7 kg to 387.2 kg), backfat thickness (from 7.45 mm to 12.23 mm) and marbling score (from 1.09 to 8.31). In contrast, significantly decreased levels of meat color, fat color, texture and maturity were apparent with increasing quality grade (p<0.05). Increasing quality grade was also correlated with significant increases (p<0.05) in crude fat contents (from 3.57% to 25.68%) and water holding capacity (from 52.41% to 58.03), and a decrease of the Warner-Bratzler shear force from 8.29 kg to 2.83 kg. The highest $L^*$ value (41.53) and highest cooking loss (22.11%) were observed with grade $1^{++}$ and 3 beef, respectively. There was no difference observed on $pH_{24}$ (5.53 to 5.66) among the quality grades, which were within the normal range. Sensory evaluation experiments revealed that quality grades were associated with significantly altered (all p<0.05) tenderness, juiciness, flavor, and overall acceptability. The crude fat contents showed significant correlation with juiciness (r=0.59), tenderness (r=0.71), flavor (r=0.55), and overall acceptability (r=0.69). The lower sensory trait scores were related to higher WBs. Grade $1^+$ Hanwoo beef had a significantly higher WBs and lower fat contents when compared to grade $1^{++}$ Hanwoo beef (p<0.05).

성별이 한우 등심의 육질등급요인, 이화학적 및 관능특성에 미치는 영향

이종문,최주희,오미화,김용수,천동원,서상철,황규석,장애라,Lee, Jong-Moon,Choe, Ju-Hui,Oh, Mi-Hwa,Kim, Yong-Su,Cheon, Dong-Won,Seo, Sang-Chul,Hwang, Kyu-Seok,Jang, Ae-Ra 한국축산식품학회 2010 한국축산식품학회지 Vol.30 No.2

The effect of cattle sex (cow, bull, and steer) on carcass traits of quality grade factors, physicochemical, and sensory traits of Longissimus Dorsi in Hanwoo was evaluated. Carcass traits of 42,113 heads were collected nation-wide and 257 heads were slaughtered to analyze beef quality. Sex affected significantly marbling score, meat color, fat color, texture, maturity, and quality grade of Hanwoo (p<0.05). Hanwoo steer carcasses had the highest marbling score (5.02), maturity (2.17), and texture (1.31) than those of cows and heifers. Crude fat of steers was higher than that of other cows and bulls. Steers showed the highest $L^*$(39.01), Warner-Bratzler shear force (4.03 kg), and water holding capacity (57.08%), however, there was no significant differences between those of cows and bulls. Ultimate$pH_{24}$ was shown difference among sex (5.58-5.69), however, the values remained within normal range. In sensory evaluation analyses, sex affected significantly tenderness, juiciness, and flavor (p<0.05). Also, the over all acceptability of steer beef was significantly higher than that of cow and bull beef. These results could be used as fundamental data set for further research activities to elevate Hanwoo beef qualities (p<0.05).

거푸집 패널이 부착된 1방향 중공슬래브의 구조 성능

허무원 ( Moo-won Hur ),채경훈 ( Kyoung-hun Chae ),황규석 ( Kyu-seok Hwang ),윤성호 ( Sung-ho Yoon ),박태원 ( Tae-won Park ) 한국구조물진단유지관리공학회 2021 한국구조물진단유지관리공학회 논문집 Vol.25 No.1

이 연구에서는 기존 중공재의 형상을 개선한 거푸집용 중공슬래브를 개발하였고, 개발된 VPS를 활용하여 휨 및 전단 실험을 수행하여 그 성능을 평가하였다. VPS의 휨 성능 실험 결과, FPS 계열 실험체의 경우 항복 하중 값은 FPS-00 실험체 대비 약 97.5%를 나타내고 있어 항복하중 값에는 큰 차이가 없는 것으로 나타났다. 또한, FNS계열 실험체도 FPS-00 실험체 대비 약 97%를 나타내어 휨 성능에는 중공재에 의한 영향이 거의 없는 것으로 나타났다. 따라서 슬래브 시스템을 VPS로 슬래브 설계에 적용할 때 건축구조기준의 설계식으로 적용하는데 문제가 없을 것으로 판단된다. VPS의 전단 성능 실험 결과, SS-00 실험체 대비 약 92%로 나타나 SS-00 실험체에 비하여 다소 부족한 것으로 나타났다. 이는 전단강도 식이 콘크리트에 의한 전단력과 철근에 의한 전단력의 합으로 표현되는 설계 식에 따라 중공재에 의하여 콘크리트 단면이 삭제되었기 때문인 것으로 판단된다. 하지만, 휨설계와 동일하게 전단설계에 적용되는 구조체의 내력도 최대하중 값을 기준으로 하는 것이 아니라 항복 하중 값을 기준으로 설계에 적용하게 된다. In this study, we developed Void Plywood Slab (VPS) that improved the shape of existing hollow materials. Its performance was evaluated through one-way flexural and one-way shear tests using the developed VPS. As a result of the one-way flexural performance tests of VPS, the yield load value for FPS series(longitudinal direction specimens with hollow materials) was approximately 97.5% compared to FPS-00(without hollow materials) specimen. The tests showed that the yield load was not much different. In addition, FNS series(transverse direction specimens with hollow materials) also represented about 97% of FPS-00 specimen. The one-way flexural performance was shown to have little impact from void materials. Therefore, it is confirmed that the presented system is applicable to the VPS to the slab design. The results of the one-way shear performance tests of VPS showed that it was about 92% compared to the SS-00(without hollow materials) specimen. These results were somewhat insufficient for the SS-00 specimen. Shear strength equation is expressed as the sum of shear force by concrete and shear force by reinforcement. However, in the case of void slab, it is believed that the concrete section has been deleted by the void material. However, the strength of the structure applied to the shear design, as with the flexural design, is also applied to the design based on the yield load value.