Recently, in newly constructed apartment buildings, the exterior wall structures have been characterized by thinness, having various openings, and a significantly low reinforcement ratio. In this study, a nonlinear finite element analysis was performed to investigate the crack damage characteristics of the exterior wall structure. The limited analysis models for a 10-story exterior wall were constructed based on the prototype apartment building, and nonlinear static analysis (push-over analysis) was performed. Based on the finite element (FE) analysis model, the parametric study was conducted to investigate the effects of various design parameters on the strength and crack width of the exterior walls. As the parameters, the vertical reinforcement ratio and horizontal reinforcement ratio of the wall, as well as the uniformly distributed longitudinal reinforcement ratio and shear reinforcement ratio of the connection beam, were addressed. The analysis results showed that the strength and deformation capacity of the prototype exterior walls were limited by the failure of the connection beam prior to the flexural yielding of the walls. Thus, the increase of wall reinforcement limitedly affected the failure modes, peak strengths, and crack damages. On the other hand, when the reinforcement ratio of the connection beams was increased, the peak strength was increased due to the increase in the load-carrying capacity of the connection beams. Further, the crack damage index decreased as the reinforcement ratio of the connection beam increased. In particular, it was more effective to increase the uniformly distributed longitudinal reinforcement ratio in the connection beams to decrease the crack damage of the coupling beams, regardless of the type of the prototype exterior walls.

Recently, the number of cases of fire spreading due to exterior materials of buildings is increasing. Due to the nature of modern architecture, which emphasizes the aesthetics of buildings, because buildings pursue a splendid appearance, they are inexpensive and have relatively good insulation performance, but an increasing number of buildings are adopting insulation materials that have poor fire safety performance. The risk of spread is also greatly increased. Since the exterior wall of a building is made of a variety of materials and structures, it is composed of a combination of several elements, including materials such as insulation and finishing materials. Therefore, it was determined that it was necessary to introduce a more systematic evaluation method for building exterior materials, and to improve the system reflecting this, away from the existing evaluation method that only checked the fire safety performance of finishing materials.

본 연구는 서울시에 조성되어 있는 수직정원공간의 경관적 이미지를 파악하고 향후 수직정원 을 효과적으로 유지하기 위해서 어떠한 변수 들이 중요한 역할을 하는지를 확인하기 위한 목적 으로 수행되었다. 대상은 네이처리퍼블릭 명동유네스코점과 돈의문박물관마을 외벽의 수직정 원이고 네이버 설문조사 툴을 이용하여 조사를 시행하였다. 분석기법은 기술통계분석과 인자 분석 및 다중회귀분석을 실시하였다. 네이처리퍼블릭 명동점 전면부 수직정원에 대한 시각적 이미지 평가는 깨끗하고 아름다우며 흥미로운 공간이미지를 구축하고 있는 것으로 파악되었 다 ‘신비로운-신비롭지 않은’, ‘연속적인-단절된’ 등의 변인은 상대적으로 낮은 평가치를 보이 고 있는 바 이는 명동 한복판의 독립된 사각형 건물로 인한 영향으로 생각된다. 돈의문박물관 마을 수직정원은 특이하고 아름다운 경관으로 인지됨을 볼 수 있다. 반면 ‘높은-낮은’, ‘넓은- 좁은’, ‘정돈된-정돈되지 않은’ 등의 변인은 다소 부정적 의미의 평가를 받았다. 모두 4개의 인 자군으로 공간이미지가 함축되어 분석되었고 전체 변량 중 이들 인자군의 설명력은 69.88%였 으며 30.20%는 오차변량과 특수변량이라 볼 수 있다. 인자분석 결과를 토대로 수직정원의 시각 적 이미지를 설명하는 인자를 ‘특이성인자’, ‘자연성인자’, ‘정연성인자’, ‘개방성인자’ 등 4개로 분류하였다. 수직정원 경관에 대한 시각선호에 가장 영향을 높게 미치는 변인은 자연성인자 및 정연성인자로 나타나 수직정원의 전반적인 경관이미지가 자연적 아름다움에 의해 좌우되고 있 음을 보여주고 있다.

2018년 여름의 폭염은 기상관측을 시작(1907년 10월 1일)한 이래 111년 만에 가장 높은 기온을 기록하였는데, 서울은 39.6℃를 기록(2018년 8월 1일)하여 종전의 기록인 38.4℃(1994년 7월 24일)를 뛰어넘었다. 열섬현상으로 인해 도시의 온도가 상승하고 하절기 열쾌적성이 저하됨에 따라 하절기 열환경 개선에 대한 연구가 지속적으로 진행되고 있다. 본 연구의 목적은 조경공 사 전·후의 온도저감 및 외부공간 이용자가 느끼는 열환경 개선에 대하여 정량적으로 검증하여 설계 및 시공단계에서 활용할 수 있는 기초적 자료를 제공하고자 하였다. 연구결과는 다음 과 같다. 미기후 실측에 의한 측점별 조경공사 전·후의 온도저감을 비교 분석한 결과, 오전 10 시 조경공사 전 평균온도는 34.5℃이며, 조경공사 후 평균온도는 32.5℃로 2.0℃온도저감 효과가 있는 것으로 분석되었으며, 오후 2시 조경공사 전 평균온도는 37.5℃이며, 조경공사 후 평균 온도는 35.9℃로 1.6℃ 온도저감 효과가 있는 것으로 분석되었다. 오후 5시 조경공사 전 평균온 도는 33.8℃이며, 조경공사 후 평균온도는 31.2℃로 2.6℃ 온도저감 효과가 있는 것으로 분석되었다. 연구결과의 활용방안으로 정량적인 연구방법과 결과는 디자이너의 직관적인 조경설계에 객관성을 부여하는 기초자료로서 활용이 가능할 것이다.

The objective of this research is to evaluate the effect of adhesive types on dimensional stability of bamboo-oriented particleboard. The materials used in this research are bamboo tali(Gigantochloa apus J.A & J.H. Schult. Kurz), UF/MDI(8, 10, 12 % level), and MF, MDI, and PF at 7 % level. Particle and adhesive are mixed using a blending machine; then, mat forming and hot pressing processes are performed using adhesive-suitable temperature and time references. MDI resin is set at 160 ºC temperature for 5 minutes. PF resin and MF resin are pressed at 170 ºC for 10 minutes, and 140 ºC for 10 minutes, respectively, while UF/MDI sets at temperature of 140 ºC for 10 minutes. The results show that particleboard using PF resin produces the lowest thickness swelling value. The particleboard using UF/MDI resin also produces good response for thickness swelling value. Interesting things happen in that UF/MDI adhesive produces a thickness swelling value better than that of MDI resin. FTIR analysis on particleboard bonded by UF/MDI resin combination shows the presence of carbonyl group C=O vibration on multi substitution of urea at wave number of around 1,700 cm-1.

In this paper, we analyzed the safety on static and dynamic characteristics of a top-down evacuation instrument fixed on the exterior walls of a building using finite element analysis. For this purpose, the stress distribution characteristics of the H-beam structure were analyzed and the equivalent stress distribution, deflection displacement and natural frequency characteristics of the overall structure of the evacuation instrument were analyzed. The structures were applied with the materials of SS440 and SUS304. The static analysis results showed the elastic behavior with safety coefficients from 2.4 to 2.9, by confirming the structural safety. In addition, the analysis of the natural frequency characteristics confirmed that the vibration characteristics were higher than the external conditions of 20Hz.

In this study, the whole process of 6xxx series aluminum extruded alloy for high speed train interior and exterior parts are characterized. The mechanical properties, and chemical composition of the case materials were evaluated for the 6063, 6061 and 6N01 alloy profiles and compared to the commercial materials and the evaluation results satisfied the standard. The cast product was extruded using the air slip(AS) casting method and the direct casting(DC) method and these were again heat-treated conditions with T5 or T6. The remarkable point is that the extrusion temperature and pressure of 6061 alloy were somewhat higher than those of other alloys. The reason is that 6061 alloy exhibited brittle fracture due to grain boundary segregation even at the tensile fracture surface and the fact that the product used a billet by the direct casting method instead of air slip one. The mechanical properties were evaluated for the 6063, 6061, 6N01 extruded alloys and the evaluation results were analyzed and satisfied the standard properties.

In this study, the extrusion process of 6xxx series aluminum cast alloy for high speed train interior or exterior parts are developed. For casting, selection of optimum alloying elements, dissolution technology, de-gassing process, production of molds conforming to the conditions of use, development of casting process control technology for various shapes and materials are performed for the development of high-quality, high strength aluminum alloys. The development of more high farmable extruded aluminum casting alloys for interior or exterior materials has been the scope of this study. The extruded die design was performed for the 6063, 6061 and 6N01 alloy profiles and extrusion test was executed. From these results, the extrusion conditions such as extrusion pressure following as billet temperature and materials were carefully examined.

In this study, the whole process of 6xxx series aluminum cast alloy for high speed train interior or exterior parts are characterized. For casting, selection of optimum alloying elements, dissolution technology, de-gassing process, production of molds conforming to the conditions of use, development of casting process control technology for various shapes and materials are performed for the development of high-quality, high strength aluminum alloys. The development of more reliable lightweight aluminum and aluminum alloy for interior or exterior materials has been the scope of this study. The mechanical properties, and chemical composition of the case materials were evaluated for the 6063, 6061 and 6N01 alloy profiles and compared to the commercial materials and the evaluation results satisfied the standard.

In this study, we conducted a shake table test to verify the seismic performance of the paneling system with steel truss composed of bolt connections. The control group was set to the traditional paneling system with steel truss connected by spot welding method. Test results showed that the bolted connection type paneling system has excellent deformation capacity without cracking or brittle fracture of the steel truss connection parts compared to the welding type paneling system. Furthermore, in the bolted connection type, slight damage occurred at the time of occurrence of the same story drift angle as compared with the existing method, it is considered that it has excellent seismic performance. In compliance with the performance-based design recommended for the current code (ASCE 41-13) on non-structural components, it is judged that in the case of the bolted connection type paneling system, it can be applied to all risk category structures without restriction. However, in the case of traditional paneling system with spot welding method, it is considered that it can be applied limitedly.

함정 외부 탑재 장비의 복잡한 형상에 의해서 발생하는 다중반사는 경로를 예측하기 어렵고 높은 RCS(Radar Cross Section) 의 원인이 된다. 따라서 함정의 외부 탑재 장비의 최적배치 설계가 RAS(Radar Absorbing Structure) 방법으로 고려되어야 한다. 본 논문에 서는 함정 외부 탑재 장비에서 발생하는 다중반사와 RCS를 최소화하기 위하여 함정 외부 탑재 장비 최적배치를 수행하였다. 외부 탑 재 장비 최적배치에 사용된 알고리즘은 순차적 내림차순 방법을 이용하였다. 함정 외부 탑재 장비 최적배치를 수행하기 위하여 LCS-2 type을 해석 모델로 선정하였다. 계산 비용을 줄이기 위해서 장비의 기여도 분석 및 다중반사 경로 분석 등을 통해 최적 배치를 수행 할 장비를 선정하였고 최적배치를 통해 RCS가 최소가 되는 최적배치 위치를 도출하였다. 또한 RCS 변화에 따른 레이다의 탐지거리 변 화율을 이용하여 RCS 감소효과를 분석 하였다.

To investigate the cyclic characteristics of the retrofitted exterior joints of RC frame with haunch, 70% scaled 6 beam-column exterior joint subassemblies were designed according to design guideline according to 1988 and tested with cyclic loading up to 3.5% story drift ratio. During the experiments axial forces are applied to columns to simulate gravity load. Experimental results shows that the strength of retrofitted specimens was increased steadily until 2.5% story drift ratio and their strengths increased more than 1.7 times of the non-retrofitted in case that main bar was bent away from exterior joint. The joint strength and effective stiffness of the retrofitted specimen was increased and results in more deformation capacity compared to the non-retrofitted.

In the moment frame subjected to earthquake loads, beam-column joint is structurally important for ductile behavior of a system. ACI Committee 352 proposed guidelines for designing beam-column joint details. The guidelines, however, need to be updated because of the lack of data regarding several factors that may improve the performance of joints. The purpose of this study is to investigate the seismic performance of reinforced concrete exterior joints with high-strength materials and unbonded tendons. Three specimens with different joint shear demand-to-strength ratios were constructed and tested, where headed bars were used to anchor the beam bars into the joint. All specimens showed satisfactory seismic behavior including moment strength of 1.3 times the nominal moment, ductile performance (ductility factor = at least 2.4), and sufficiently large dissipated energy.

In this paper, Nonlinear Static Pushover analysis method(NSP) is proposed which apply to RC buildings reinforced by external retrofit fornseismic performance. Based on previous analysis and research, NSP is more developed by connection nonlinearity according to shearnresistance mechanism such as dowel and adhesive resistance as major shear resistance elements. According to the proposed method,nstructural analysis for example buildings was carried out to evaluate seismic performance of buildings. And, it was confirmed thatndepending on shear strain and characteristics of joint resistant of external retrofitting are different from internal retrofitting. Furthermore,nthe strength reduction coefficient of the anchor needs to be considered at the joint design.

구형 충격을 받는 필름 코팅된 유리 시스템의 거동을 개발한 유한 요소 프로그램에 의하여 연 구하고자 한다. 충격 거동을 예측하기 위하여 Sun의 higher order beam theory와 Kurapati의 generalized power law와 연계한 새롭고 효과적인 동적 유한 요소법을 제안한다. 필름 코팅된 유리 시 스템과 모놀리식 유리에 대하여 접촉력, 변형량, 운동에너지, 속도 및 응력 등을 계산한 후 결과를 비교 검토하여 코팅 시스템의 필름이 충격 손상을 방지하고 충격 저항이 우수하다는 것을 정성적 및 정량적으로 규명하였다.