Mero 시스템의 절점응력 분포특성에 관한 실험적 연구

강종,김성은,최현식 대한건축학회지회연합회 2007 대한건축학회지회연합회 학술발표대회논문집 Vol.2007 No.1

볼접합부를 갖는 원형강관의 좌굴내력 평가

강종 대한건축학회지회연합회 2011 대한건축학회연합논문집 Vol.13 No.3

스페이스 프레임은 구조특성상 불안정 현상의 하나인 좌굴이 발생되기 쉬우며 이는 구조물의 내력을 결정하는 중요한 요소가 된다. 따라서 이 연구에서는 선행연구결과를 기초로 하여 볼접합부를 갖는 원형강관의 부재좌굴내력을 평가하고 이를 국내외의 압축재 설계규준과 비교․분석함으로써 부재설계의 합리성과 안전성을 평가하고자 하는 데에 목적이 있다. 좌굴내력 평가에 적용될 원형강관은 ∅42.7×2.3 및 ∅48.6×2.8의 2종류를 선정하였다. 각 종류별 세장비는 50과 90의 2가지로 하였으며 단부 지지조건은 양단 핀과 고정으로 하였다. 국내외의 압축재설계규준으로는 우리나라의 하중저항계수 설계법(Load Resistance and Factor Design), 일본의 한계상태 설계법(Limit State Design), British Stanadard BS5950 및 Eurocode 3 총 4종류의 규준을 적용하였다. 선행연구의 실험결과와 국내외의 4가지 설계규준과의 좌굴내력을 비교․분석하였다. 그 결과를 요약해보면 다음과 같다. 첫째, 좌굴실험결과에 의한 좌굴응력이 각국의 압축재 설계규준에 비해 최소 1.06배에서 최대 1.49배 큰 것으로 나타났다. 또한 양단 핀 지지조건의 실험체만 고려할 경우에는 평균 1.2배로, 양단 고정 지지조건의 실험체만 고려할 경우에는 평균 1.15배로 나타났다. 둘째, 각국 설계규준에 의한 좌굴내력의 크기는 양단 핀 지지조건일 경우 BS규준, Eurocode, 우리나라의 하중저항계수 설계법, 일본의 한계상태 설계법의 순서이며, 양단 고정 지지조건일 경우 우리나라의 하중저항계수 설계법, BS규준, Eurocode, 일본의 한계상태 설계법의 순서로 나타났다. The objective of this study was to estimate the member buckling strength of a circular steel pipe and to investigate the rationality and safety of the buckling design by comparative analysis with domestic and foreign design codes on the compression member. The two types of the circular steel pipe such as ∅ 42.7 × 2.3 and ∅ 48.6 × 2.8 were chosen to test the buckling strength. The types of three apparatus were 50 and 90 and the supporting condition of single section was used with the pin and the holder at both ends. The domestic and foreign codes on the compression member that were applied to the estimation were Load Resistance and Factor Design of Korea, Limit State Design of Japan, and British Standard BS5950 and Eurocode 3. In this study, we compared and analyzed both the results of previous studies and the domestic and foreign design codes on the buckling strength. The results were summarized as follows: First, according to the results of the experiment on buckling, the buckling stress appeared to be greater from at least 1.06 times to maximum 1.49 times than the design codes of compression member used in every country. In addition, the buckling stress was about 1.2 and 1.15 times in the specimen of the supporting condition with the pin and the holder at both ends, respectively. Second, the size of the buckling strength by the design codes of every country was in the order of British Standard BS5950, Eurocode 3, Load Resistance and Factor Design of Korea, and Limit State Design of Japan in the case of the supporting condition with the pin at both ends, and in the order of Load Resistance and Factor Design of Korea, British Standard BS5950, Eurocode 3, and Limit State Design of Japan in the case of the supporting condition with the holder at the same position.

볼-볼트 조임식 접합부 슬리브의 응력분포특성에 관한 실험적 연구

강종,김성은,최현식 대한건축학회지회연합회 2008 대한건축학회연합논문집 Vol.10 No.1

The evaluation of joint stiffness is very important to design the space frames with ball-bolted joints. In this paper, the characteristics of stress distribution and neutral axis on the sleeve of ball-bolted joint at space frame are analyzed for the evaluation of the stiffness by the experimental approach. Six types of pipes, ∅42.7×2.3, ∅48.6×2.8, ∅60.5×3.2, ∅89.1×3.2, ∅114.3×4.5, and ∅139.8×4.5, are selected, and so the test models with the detailed partial specifications which are widely used in the domestic construction field are constructed for the bending test of joints. The strains of the joints are measured by the strain gages attached to the sleeves and pipes to investigate the characteristics of mechanics in it, and the deflection of the test models are also measured by LVDT positioned in the lower middle of the ball. In results, after initial phase of loading, the compressive stresses are concentrated at the upper surface of the sleeve with the gap in the lower boundaries of the ball and sleeve, and the sleeve and cone. Also, the neutral axis is nearly positioned at the nearest strain gage position from the middle axis of the sleeve cross section. It shows the tendency that the neutral axis moves from the compressive zone to the tensile one according to increasing the load. It is founded that the distribution of compressive strains from the neutral axis is not linearly distributed on the sleeve, and the strain on the extreme fiber of sleeve shows the state of concentrated stress. The maximum strains on the extreme fiber are 1.24 times of the linearly distributed strain fiber in BS427m12, 1.27 times in BS486m16, 1.4 times in BS605m20, 1.15 times in BS891m24, 1.72 times in BS1143m30, and 1.46 time in BS1398m36.

1980년도 표준설계도에 준하여 건설된 학교건축물의 내진보강기법 연구

강종,Kang. Jong 한국방재학회 2012 한국방재학회논문집 Vol.12 No.1

내진보강기법에 따른 성능평가 수치해석 결과 철근콘크리트 전단벽이 가장 우수한 것으로 평가되었다. 또한 X형 철골가새, K형 철골가새 및 knee형 철골가새의 순으로 내진성능이 우수한 것으로 나타났다. 학교건축물의 평면 기능성을 유지시키면서 내진보강 구조물이 설치가능한 곳에 보강을 하더라도 기존의 보 및 기둥골조에 부재별 별도의 보강이 필요한 보강기법은 4층 학교건출물에서는 K형과 knee형 철골가새로, 3층 학교건출물에서는 knee형 철골가새로 나타났다. 내진보강기법에 대한 성능평가 및 장단점에 대하여 종합적으로 분석해 보면 전단벽 방식이 효율성 측면에서 가장 우수한 것으로 나타났다. 설치 후 외관의 형태에 변화를 주거나 개구부의 크기 및 위치에 제약조건이 수반되는 철골가새 보강방식과는 달리 기존 개구부의 크기와 위치를 그대로 유지시키면서 철근콘크리트 전단벽 구조로 보강함으로써 외관에 영향을 주지 않는다. 또한 기존 벽체의 중량에 변화를 주지 않도록 두께를 선정함으로써 기초보강의 필요성이 배제되었다. We considered the practical aspects to the seismic performance evaluation method and adopted a numerical approach using a universal program, MIDAS-GENw applied the KBC-structural design standards 2009. The four types such as reinforced concrete shear walls and X-type, K-type, and knee-type steel braces were chosen to the seismic retrofit techniques. The results were summarized as follows: First, the results of a numerical approach to the performance evaluation according to the seismic retrofit techniques, the excellence of the seismic performance was in the order of reinforced concrete shear walls and X-type, K-type, and knee-type steel braces. Second, when installing the shear walls in 24 places among 65 places that can enhance in the direction of X and in 11 places among 49 places that can enhance in the direction of Y, in the case of the four-story school building the structural reinforcement by the action of the earthquake loads in the existing beams and the columns framing may not be require.

비내진 설계 내력벽방식 공동주택의 보강기법에 따른 내진성능평가

강종 한국방재학회 2011 한국방재학회논문집 Vol.11 No.6

The aim of this study was to investigate the security and reliability of structure based on performance objective on the seismic performance evaluation according to the seismic reinforcing formality of reinforced concrete wall-structural apartment building without seismic design. To evaluate the seismic performance, FEMA 356 was selected as guidelines and pushover analysis was conducted with nonlinear static analysis. The maximum story drift ratio before reinforcement of existing structures in 500 recurrence period was 0.66% which exceeded life safety level, but the performance was improved due to decrease of the safety level (0.47%) after internal and external reinforcement. Moreover, the maximum story drift ratio of existing structures in 2400 recurrence period was 1.31% which exceeded life safety level, but the performance was improved because the ratio appears to be below the safety level (0.93%) after internal and external reinforcement. 내진설계가 되지 아니한 철근콘크리트 내력벽식 공동주택의 내진보강 형식에 따른 내진성능 평가를 수행함으로써 성능목표를기초로 한 구조물의 안전성과 신뢰성을 확보하고자 하였다. 내진성능을 평가하기 위해 FEMA 356을 채택하였으며, 비선형 정적해석으로 pushover 해석을 수행하였다. 해석결과, 500년 재현주기에서 기존 건축물의 보강전 최대층간 변위각 비는 0.66%로기능수행 수준을 상회하고 있으나 내·외부 내력벽 보강을 했을 경우에는 0.47%로 성능이 보다 향상되어지는 것으로 나타났다. 그리고 2400년 재현주기에 있어서 기존 구조물의 최대 층간변위비는 1.31%로 인명안전수준을 초과하였으나 내·외부 보강 후0.93%로 인명안전수준 이하로 나타나 성능이 향상되었음을 알 수 있었다.

스페이스 프레임 구조물의 부재좌굴성능 평가방안 연구

강종 한국구조물진단유지관리공학회 2018 한국구조물진단유지관리공학회 논문집 Vol.22 No.1

The purpose of this study was to investigate the safety and rationality of buckling strength and length coefficient by comparing with the design standards of domestic and foreign compression materials based on the buckling test results of circular steel pipe with ball joints. The types of round steel pipes selected for buckling performance evaluation were ø48.6 × 2.8t, ø60.5 × 3.2t and ø76.3 × 3.2t. For the design of domestic and foreign compression materials, Korea 's Load Resistance and Factor Design, Japan' s Limit State Design, and British Standard BS5950 standard were applied. In this study, we compared and analyzed the buckling performance between the experimental results of the previous research and the domestic and foreign design standards. The results were summarized as follows. As a result of applying the full length of the member to the buckling length in the compression materials design standards of each country, it was 64-89% of the buckling strength by the experiment. Therefore, it is deemed desirable to perform the member design according to the current design standard formula for safety. Experimental results show that the measured buckling strength was 1.02-1.43 times higher than the buckling strength of pure cylindrical steel tubes in the design standards of Korea, Japan and the United Kingdom compression materials. Consequently, it seemed that the buckling strength of individual member in the design of space frame structure should be considered buckling coefficient as the length of pure round steel pipe rather than the length of inter-node. 본 연구의 목적은 볼접합부를 갖는 원형강관의 좌굴실험 결과를 토대로 하여 국내외 압축재 설계규준과 비교 평가함으로써 부재의 좌굴내력 및 좌굴길이 계수의 안전성과 합리성을 조사하는 것이다. 좌굴성능 평가를 위해 선정된 원형강관은 ∅48.6×2.8t와 ∅60.5×3.2t 및 ∅76.3×3.2t이다. 국내외 압축재 설계를 위해 우리나라의 하중저항계수 설계법(LRFD), 일본의 한계상태 설계법(LSD) 및 영국의 BS5950 규준을 적용하였다. 본 연구에서는 선행연구의 실험결과와 국내외 설계규준과의 좌굴성능을 비교 분석하였다. 그 결과를 요약해 보면 다음과 같다. 각국의 압축재 설계규준에서 부재의 전체길이를 좌굴길이로 적용한 결과 실험에 의한 좌굴내력의 64%∽89% 정도로 나타났다. 따라서 안전을 위해 현재 설계 규준식에 준하여 부재설계를 수행하는 것이 바람직하다고 판단되었다. 실험결과 측정된 좌굴내력은 우리나라, 일본 및 영국의 압축재 설계규준에서 좌굴길이를 순수 원형강관만으로 고려한 좌굴내력 값에 비해 1.02배∽1.43배 높은 것으로 나타났다. 따라서 스페이스 프레임 구조물 설계에 있어 개별부재 좌굴내력은 절점 간 길이가 아닌 순수 원형강관의 길이로 좌굴계수를 고려할 필요가 있을 것으로 보여 진다.

볼조인트 접합부의 강성 평가에 관한 연구

강종,김성은,최현식 대한건축학회지회연합회 2009 대한건축학회연합논문집 Vol.11 No.1

The evaluation of the joint rigidity is very important to design the space frames with ball joints. The structural characteristic of the joint is one of the critical factors to evaluate the structural behavior and strength. Therefore, the purpose of this paper is to propose the reasonable evaluation method of the joint rigidity based on the proceeding studies. This method is the approximate evaluation method of rotational rigidity of joint, and it's case studies of the initial rotational rigidity are exercised. Also, the moments of inertia of the joints for the sectional shapes are evaluated and compared by the experimental results theoretical ones. The results of this paper are summerized as follows; The theoretical approach is needed to analyze the experimental results, the moments of inertia evaluated by introducing the simple assumption show a good agreement with ones obtained from the numerical method. It is regarded that the assumption used in theoretical approach is reasonable. The moments of inertia evaluated geometrically from the cross sections show the values which are higher than about 1.8 times that obtained by the experimental results. The plastic moments calculated by the theoretical approaches are 1.3 times that of yielding moment of experimental results. Eventually, these results should be a useful data to identify the structural behavior of the space frame and evaluate the buckling strength of the members and the systems.

Mero시스템의 절점회전강성 평가에 관한 실험적 연구

강종,김성은,최현식 대한건축학회지회연합회 2008 대한건축학회지회연합회 학술발표대회논문집 Vol.2008 No.1

The evaluation of joint rotational stiffness of Mero system is studied and discussed in this paper. Four types of pipes, ∅ 60.5×3.2, ∅89.1×3.2, ∅114.3×4.5, and ∅139.8×4.5 were used in the bending test models. In the test results, the initial rotational stiffnesses of the Mero system were evaluated as about 3,800kN․cm/rad in BS605m20, 7,100kN․cm/rad in BS891m24, 12,300k N․cm/rad in BS1143m30, and 30,000kN․cm/rad in BS1398m36.

기존 학교건축물의 내진보강기법에 따른 내진성능평가

강종(Kang Jong) 한국산업융합학회 2012 한국산업융합학회 논문집 Vol.15 No.1

Reinforced concrete shear walls and X-type steel braces were applied in seismic retrofit techniques for seismic performance evaluation of school buildings constructed in accordance with standard design announced by the ordinance of the ministry of construction in 1980s. Seismic performance evaluation was based on FEMA 356 using response spectrum as elastic analysis and conducted to pushover analysis with nonlinear static analysis. The maximum displacement ratio between floors in 4th and 3rd floors of the existing school buildings was less than 1.0%, which was functioning level in FEMA 356. However, because plastic hinge occurs somewhat in structural members according to the results of pushover analysis, partial reinforcement will be required. X-direction of the maximum lateral displacement of reinforced concrete shear walls than X-type steel braces was 45% and 32% in 4th and 3rd floors of school buildings, and Y-direction was 18% and 17%, respectively.

볼접합부를 갖는 원형강관부재의 좌굴길이 평가

강종(Kang Jong) 한국산업융합학회 2012 한국산업융합학회 논문집 Vol.15 No.1

The Buckling of the member under compressive stress is likely to occur, which is an important factor determining the strength of structures. The objective of this study was to evaluate the member buckling strength of a circular hollow steel with ball joints and to compare with design specifications for load resistance factor of our country. Furthermore, we would like to suggest basic data for evaluation of buckling length of a circular hollow steel with ball joints according to comparative analysis. These results were summarized as follows: Buckling stress according to the test results on buckling was 1.21 times greater than LSD specifications of our country estimated the entire length of circular hollow steel with ball joints as buckling length. In addition, it was 1.16 times greater than when estimating the length except the ball as buckling length and 1.14 times grater than when excluding the ball and sleeve. Therefore, when estimating buckling stress of circular hollow steel with ball joints, their buckling length may be measured by the length except ball and sleeve.