A finite element analysis modeling is proposed to evaluate welding joint part of steel-frame. Based on the experimental results, A finite element analysis model was proposed to analyze the welding joint of steel-frame specimens. The numerical results predicted the experimental behavior of the welding joint of steel-frame specimens well. Therefore, it is possible to use the proposed finite element analysis model to evaluate middleand low-rise steel-frame buildings constructed in South Korea.
In this study, the artificial neural network (ANN) based estimation method for rotational stiffness of column-beam connection in steel moment frames is presented. Three story and one bay steel moment frame is used as the example structure. Natural periods and mode-shapes are used as the input data and the rotational stiffness values of connections are used as the output data.
The non-welded building hardware method can reduce accidents caused by welding, and can be constructed by bolt assembly, which can reduce labor costs and shorten the construction period. This study is to compare and verify the performance according to the location where the brackets are joined to the joints using the non-welded building hardware method
In recent years, non-welded building hardware that can be installed by bolt assembly is used, which does not require fire prevention related materials, fire fighting equipment and personnel. However, there is a need for a method to compensate for the occurrence of buckling at the bolted portion at the time of construction.The purpose of this study is to evaluate the behavior of joints that can control the sliding between members by using anti slip brackets.
This study investigates structural behaviors such as ultimate strength and weld metal fracture mechanism of carbon steel (SS400) fillet-welded connections with shielded metal arc welding (SMAW) through monotonic tensile test. Specimens of TFW series (transverse fillet weld against loading direction) and LFW series (longitudinal fillet weld) failed by tensile fracture and shear fracture, respectively in the weld metal of connections. Test strengths of specimens were compared according to welding direction and weld length.
In the nuclear power plant, safety-related structures have been used above No. 11 rebar. It needs to mechanical connection device to join RC to SC walls because ACI 349 presents that lap splices shall not be used for bars larger than No.11 bar. The tensile performance tests were performed to confirm structural integrity on the mechanical connection device. But performing the tests in accordance with various connection cases has limitations, such as time or cost. Therefore, computational analysis methodology is developed in order to verify structural integrity for various connection cases.
Concrete structures built by 3D printing technology is formed as the several concrete layers. Thus, 3D printing technology for concrete structure could have less strength than the design. In this study, fracture energy (fracture toughness) tests for layered concrete in various condition was performed. depending on required time for stacking new layer. Based on the results of performed tests, it was found that fracture energy was decreased due to increased non-bonded time.
In this study, experiment and analysis of high-strength bolt connection under shear fatigue loading was conducted to evaluate reduction of axial force of bolt. Three type of bolt size and initial axial force were applied to specimens. As a results, it was observed that the reduction ratio of axial force, and that would be used to additional parametric study.
When reinforcing an existing reinforced concrete beam-column building with a precast concrete panel, special connection between the PC member and the RC member is required to solve the time dependent deformation of the RC member and to receive the large shear forces. The aim of this study is to obtain the shear strength of upper connection between the existing RC beam-column and infilled PC wall panels in experimentally and theoretically. Thus, the static shear loading tests were conducted on the 6 specimens with the plate connection. Shear failure was resulted from the weakest portion of interior PC panel, exterior RC, and the connection, when the PC portion which located at the center of specimen was pulled upward from the bottom. The experimental result was compared with analytical result from ACI 318M-14 Chapter 17 for the shear strength of post-installed anchor and PCI Handbook 7th edition 6.8 Structural Steel Corbel (PCI Design Handbook 7th edition, 2010) for the strength of cast-in H-beam. The analytical and experimental results show final failure at the same location. The failure loading of experiment showed larger than average 6% to that of the analysis.
This study focused on the ultimate strength and curling effect on the strength of single shear bolted connection with austenitic sainless steel (STS201) using finite element analysis. The validation of finite element analysis was verified through the comparisons of ultimate strength and fracture mode between existing test results and numerical predictions. Curling (out-of-plane deformation) was observed in both test and analysis and it reduced the ultimate strength of single shear bolted connections with relatively long end distances. Strength reduction ratio caused by curling was estimated quantitatively by maximum 19%, 32%, respectively for specimens with edge distance, 48mm and 60mm compared with strengths of uncurled connections with restrained out-of-plane deformation.
This paper deals with block shear fracture behavior in base metal of carbon steel welded connection. Monotonic tensile experiments have been conducted to investigate the structural behaviors of carbon steel fillet-welded connection with the block shear fracture in base metal. Main parameters are weld lengths in the longitudinal and transverse directions of applied force. Finite element analysis in this paper focused on the ultimate strength and fracture mode of welded connections. It was shown that predictions by finite element analysis method were in a good correspondence with test results for ultimate behaviors such as fracture mode and ultimate strength.
This study is to investigate the ultimate strength and curling influence of single shear two bolted connection with 7075-T6 aluminum alloys. The validation of element analysis was verified through the comparison between test result and finite element analysis prediction and strength reduction rate by curling was estimated quantitatively. Moreover, additional parametric analysis with extended variables was conducted and the conditions of curling occurrence according to end distance and edge distance were proposed.
In water treatment facilities, cover having a various joint is applied to prevent the bad smell. In this study, each joint type of the aluminum cover that is applied to the sewage treatment facility, it was evaluated air tightness. As a result, it showed to be higher flat type better than stick out type.
본 연구에서는 고온시 고강도강재를 사용한 엔드플레이트 접합부의 회전 거동 변화를 파악하기 위해 유한요소 해석프로그램을 이
용하여 모델링하고 기존 연구를 대상으로 비교분석한다. Eurocode 3에서는 휨 저항모멘트에 대한 예측식이 주어지고, 이를 통해 3가지 파괴모
드를 파악한다. 해석 모델은 온도, 엔드플레이트 두께 및 강재를 변수로 하여 이에 따른 초기회전강성, 소성회전강성 및 휨 저항모멘트 등을 분
석한다. 회전강성 및 휨 저항모멘트는 엔드플레이트의 두께 및 재료에 따른 변화를 온도 별로 분석하고 회귀식을 제시하여 고강도강재를 사용
한 접합부의 변화를 비교하고자 한다. 그 결과 초기회전강성은 1차식, 소성회전강성 및 휨 저항모멘트는 2차식으로 회귀식을 제시하였다. 고온
시 고강도강재는 일반강재에 비해 휨 저항모멘트비는 감소하였고 두께에 대한 영향이 더 작았다. 고온시 고강도강재를 적용하였을 때 상온시
에 비해 초기회전강성 기울기는 감소하였고 휨 저항모멘트의 증가율은 완만하게 나타났으며, 소성회전강성 변화는 영향을 미치지 않았다.
철골기둥-베이스 플레이트 접합부의 파괴유형은 베이스 플레이트 압축면과 인장면의 휨파괴, 앵커볼트의 인장파괴, 뽑힘, 전단파 괴, 그리고 콘크리트 기초파괴 및 철골기둥의 소성힌지발생에 따른 파괴이다. 본 연구에서는 핀접합 또는 강접합으로 가정하여 설계되는 노출 형 철골기둥-베이스 플레이트 접합부가 받을 수 있는 모멘트의 크기를 구하기 위하여, 한계상태 함수를 이용하여 철골기둥-베이스 플레이트 접합부의 휨성능 및 파괴유형을 예측하고 실험결과와 비교하였다. 한계상태함수를 이용하여 노출형 철골기둥-베이스 플레이트 접합부의 휨 성능을 비교적 정확히 예측할 수 있는 범위는 축력이 있는 경우, 앵커볼트의 항복 또는 철골기둥의 항복으로 판별되었을 때이며 축력이 없는 경 우, 베이스 플레이트의 항복으로 판별된 경우이다. 파괴유형까지 같이 고려할 경우, 축력이 있으며 앵커볼트의 항복으로 판별된 경우에만 한계 상태함수의 사용이 가능하다.
이 논문은 지진응답을 감소시키기 위해 외부설치형 카고메 감쇠시스템의 유효성을 비선형 동적 해석 결과를 통해 나타내었다. 이 전의 연구에 의해 제안된 카고메 감쇠시스템을 활용하여 본 연구에서는 등방성, 이선형 이력특성 및 설치구성이 새롭게 제안하였다. 또한, 외부접합형 카고메 감쇠시스템의 여러 가지 효과를 15층 및 20층 철근콘크리트 라멘조 아파트를 대상으로 검증하였다. 원구조물에 대한 감쇠장 치 지지구조물의 강성비, 감쇠장치의 수량 및 설치 층수는 설계변수로 고려하였다. 수치해석결과, EKDS는 기존의 한 방향 층간에 설치되는 감 쇠시스템과 비교할 때 더 작은 수를 적용하여도 두 방향의 지진하중을 감소시키는데 매우 효과적임을 입증되었다.
말뚝머리-확대기초 접합부는 상부구조물의 하중을 말뚝으로 전달하는 연결부분으로서 부재의 단면과 강성의 급격히 변화하는 부 위이기 때문에 응력이 집중되고 작용하는 휨모멘트와 전단력이 큰 취약부분이다. 이 연구에서는 제작조건에 따른 PHC말뚝 및 합성 PHC말뚝 과 확대기초 접합부의 구조성능을 평가하는데 목적이 있다. 반복가력 하중 조건하에서의 균열패턴, 하중-변위관계, 연성비, 초기 회전강성 및 에너지소산 특성을 각각 평가하였다. 접합부 초기 회전강성은 확대기초 내부로 삽입되는 말뚝삽입 깊이와 축방향철근 배근위치에 큰 영향을 받는 것으로 나타났다. 또한 접합부 강도, 연성비 및 누적 에너지소산 등의 접합부 거동은 말뚝의 종류와 축방향 철근 배근 위치에 영향을 받는 것으로 나타났다.
The purpose of this study was to analyze the reduction of clamping force of TS (torque shear) bolted connection under fatigue loading. Generally, TS bolt has been totally tightened by torque shear wrench. However the plant structures experienced various fatigue loadings that makes reduction of clamping force of TS bolt. Therefore, this study conducted to the fatigue load test.
The purpose of this study was to investigate deformation and reduction of initial clamping force in slip critical type connection under fatigue loading. And, the parameters of this study were the different clamping force and friction coefficient of surface of plate. As a result, the clamping force of all specimens were generally decreased in comparison with initial values under fatigue loading.