• Earthquakes and Structures
• /
• 제7권5호
• /
• pp.705-718
• /
• 2014

This paper presents an analytical model for determining the transverse reinforcement required for reinforced concrete exterior beam-column joints subjected to reversed cyclic loading. Although the joint aspect ratio can affect joint shear strength, current design codes do not consider its effects in calculating joint shear strength and the necessary amount of transverse reinforcement. This study re-evaluated previous exterior beam-column joint tests collected from 11 references and showed that the joint shear strength decreases as the joint aspect ratio increases. An analytical model was developed, to quantify the transverse reinforcement required to secure safe load flows in exterior beam-column joints. Comparisons with a database of exterior beam-column joint tests from published literature validated the model. The required sectional ratios of horizontal transverse reinforcement calculated by the proposed model were compared with those specified in ACI 352R-02. More transverse reinforcement is required as the joint aspect ratio increases, or as the ratio of vertical reinforcement decreases; however, ACI 352R-02 specifies a constant transverse reinforcement, regardless of the joint aspect ratio. This reevaluation of test data and the results of the analytical model demonstrate a need for new criteria that take the effects of joint aspect ratio into account in exterior joint design.

• 한국구조물진단유지관리공학회 논문집
• /
• 제12권5호
• /
• pp.74-80
• /
• 2008

본 논문은 기둥형상비를 실험 변수로 가지는 무량판 슬래브-기둥 접합부의 내진성능을 평가하는데 있다. 본 연구에서는 무량판 슬래브의 뚫림 전단파괴를 방지하기 위하여 본 연구와 병행하여 진행된 연구에서 개발된 연속 절곡된 전단보강근을 적용하였다. 기둥형상비에 따른 실험체는 각각 FIS1-05(0.5), FIS1- 10(1.0), FIS1-20(2.0) 이다. 실험체의 수평방향으로 정적 수평하중을 가력 하였으며, 중력하중비에 의한 일정 수직 하중을 적용하였다. 실험결과는 슬래브-기둥 접합부의 수평 변위 및 강도를 기준으로 평가하였다. 분석결과, FIS1-05, FIS1-20와 같은 장방형 기둥을 갖는 접합부의 성능이 FIS1-10와 같은 정방형 기둥을 갖는 접합부보다 우수한 것으로 평가되었다.

• 한국정밀공학회지
• /
• 제29권10호
• /
• pp.1078-1088
• /
• 2012

In this paper, we present research experimental results about the different thickness T-joint welding of the high power continuous wave(CW) Nd:YAG laser for the secondary battery of a vehicle. Although the conventional method used for the secondary battery is a argon TIG welding, we utilize a laser welding to improve Tungsten Inert Gas(TIG) welding's weakness. The laser, which has a couple of advantage such as aspect ratio, low Heat Affected Zone(HAZ), good welding quality and fast productivity utilized in this work is a CW Nd:YAG laser. In order to observe laser welding sections, we used a optical microscope. Through the analysis of the metallographic, hardness, aspect ratio, and heat input, we obtained the desired data in condition of 1800 W laser beam power and 1.8 m/min and 2.0 m/min laser beam travel speeds. In order to compare electric resistances of the argon TIG welding and laser welding, we made an actual battery and the electric resistance of the laser welding is reduced by 40~45% comparing with the argon TIG welding.

• 한국산업융합학회 논문집
• /
• 제10권4호
• /
• pp.255-262
• /
• 2007

The main purpose of this study is to figure out of seismic structural behaviour of Gukrakjeon of Bongjung-Temple which is the oldest wooden architecture in Korea, and to evaluate in engineering aspect of seismic records. The non-lineal analysis is essential for accurate evaluation of wooden architecture in seismic behaviour. Based on the experimental test with applying cycle forces in joint specimens is focusing on not only to prove the structural characteristics, but also to evaluate damping ratio, As the result of this test, damping ratio is affected not the joint methods but the frame variations. The average damping ratio was 26%.

• Journal of Oral Medicine and Pain
• /
• 제17권2호
• /
• pp.63-73
• /
• 1992

This study was performed for the purpose of investigating the relation between width of temporomandibular joint space and craniofacial morphology in patients with CMDs. The subjects utilized here were aged from 16 to 63 years old and 19 male and 46 female. For the study, each patient was taken radiographs by Transcranial and Lateral Cephalographic projection and the films were traced with routine method. The measured items were anterior, superior, posterior joint space and relative condylar position to the deepest part of glenoid fossa in Transcranial film and items related vertical and/or horizontal growth in Cephalogram. The data were processed with SPSS/PC+ package for statistical analysis. The obtained results were as follows : 1. Anterior joint space in affected side were wider than that of unaffected side, but for superior and posterior joint space, the value of unaffected side were more than those of affected side. 2. Superior or posterior joint space of affected side were significantly correlated with items related vertical growth, such as ramus height, Jarabak ratio, FMA. From this, the following cold be proposed, the wider the joint space of superior or posterior aspect of affected side was, the more the patient showed growth pattern of counter clockwise. 3. Superior or posterior joint space of affected side were significantly correlated with items related horizontal growth, such as SNPo, NAPo, APDI and ANB. From this the following could be proposed, the wider the joint space of superior or posterior aspect of affected side was, the more the patient showed anterior displacement of mandible. 4. It would be proposed that the diagnositic value of superior and posterior joint space of affected side in transcranial radiograph was excellent.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2001년도 가을 학술발표회 논문집
• /
• pp.67-74
• /
• 2001

In domestic, irregular walls such as T, L, H and Box shapes are considered as rectangular wall in the design of bearing wall apartment building. The strengths of walls, therefore, can be underestimated in case of using the current design process. Irregular walls are connected to each other as rigid joint so that part of the load can be resisted by the wall perpendicular to the load direction. This resistance can be caused by the effective width of perpendicular wall. This additional resistance by the perpendicular wall increases the strength of structural walls. The objective of this study is to evaluate the effective widths of flanged walls with different aspect ratios by using FEM analyses. the results from finite element method are compared with effective flange widths of some code provisions.

• 한국구조물진단유지관리공학회 논문집
• /
• 제7권2호
• /
• pp.201-208
• /
• 2003

In domestic, bearing wall apartment building have not rectangular walls but irregular walls which are designed at walls of various cross-sectional shapes such as H-shaped, T-shaped, Box-shaped and L-shaped. In these irregular walls connected with rigid joint each other, one side walls of irregular walls is expected to show effective behavior for rigid-jointed the other side walls. Moreover, previous studies have focused on simplifying irregular walls into rectangular walls because of the complication in structural design and analysis. So studies for variables affecting behaviors of irregular walls, such as aspect ratios and compressive strength of concrete, are insufficient. The objective of this study is to evaluate the behaviors of T-shaped structural walls with different concrete compressive strengths and aspect ratios by experimental works. Results of this experimental study show that flange wall is contributed to increase the flexural strengths by the variation of concrete strengths and aspect ratios, and that it is needed to evaluate the effect width of flange wall for rational wall design.

• Advances in aircraft and spacecraft science
• /
• 제6권6호
• /
• pp.515-528
• /
• 2019

The structural vibrations of a flat plate induced by fluctuating wall pressures within wall-bounded transonic jet flow downstream of a high-aspect ratio rectangular nozzle are simulated. The wall pressures are calculated using Hybrid RANS/LES CFD, where LES models the large-scale turbulence in the shear layers downstream of the nozzle. The structural vibrations are computed using modes from a finite element model and a time-domain forced response calculation methodology. At low flow speeds, the convecting turbulence in the shear layers loads the plate in a manner similar to that of turbulent boundary layer flow. However, at high nozzle pressure ratio discharge conditions the flow over the panel becomes transonic, and the shear layer turbulence scatters from shock cells just downstream of the nozzle, generating backward traveling low frequency surface pressure loads that also drive the plate. The structural mode shapes and subsonic and transonic surface pressure fields are transformed to wavenumber space to better understand the nature of the loading distributions and individual modal responses. Modes with wavenumber distributions which align well with those of the pressure field respond strongly. Negative wavenumber loading components are clearly visible in the transforms of the supersonic flow wall pressures near the nozzle, indicating backward propagating pressure fields. In those cases the modal joint acceptances include significant contributions from negative wavenumber terms.

• 국제강구조저널
• /
• 제18권4호
• /
• pp.1284-1296
• /
• 2018

Carbon fiber reinforced polymer (CFRP), plates bonding repair method is one of the simple repair methods for cracked steel structures. In this study, the influence of width of CFRP plates on bending fatigue life of out-of-plane gusset joint strengthened with CFRP plates was investigated from the experimental and numerical point of view. In the bending fatigue test of cracked out-of-plane gusset joint strengthened with CFRP plates, the effect of width of CFRP plates on crack growth life was clarified experimentally. Namely, it was revealed that the crack growth life becomes larger with increasing the width of CFRP plates. In the numerical approach, the stress intensity factor (SIF) at the surface point of a semi-elliptical surface crack was estimated based on the linear fracture mechanics. Furthermore, the extended fatigue life of cracked out-of-plane gusset joint strengthened with CFRP plates was evaluated by using the estimated SIF at the surface point and the empirical formula of the aspect ratio of semi-elliptical crack. As the results of numerical analysis, the estimated fatigue life of the specimen strengthened with CFRP plates showed the good agreement with the test results.

• 한국구조물진단유지관리공학회 논문집
• /
• 제22권1호
• /
• pp.129-136
• /
• 2018

대형 용접 구조물에 대한 피로설계 수명의 예측은 일반적으로 Palmgren Miner과 등가손상도 방법 또는 선형누적손상도 방법을 사용한다. 또한 용접 구조물에서 피로 균열이 발생되면 잔존 수명은 S-N 곡선과 선형 파괴역학에 기초하여 예측되고 있다. 본 연구에서는 면외거셋 용접이음의 3차원 피로균열 진전거동과 피로수명을 예측하기 위하여 피로 시험을 실시하였다. 면외거셋 용접이음의 3차원 피로균열진전해석은 NX NASTRAN 및 FRANC3D를 이용하여 유한요소 해석을 실시하였다. 면외거셋 용접이음의 균열 형상비, 초기균열 크기 및 응력비에 미치는 영향을 검토하기 위하여 피로균열진전 해석을 실시하였다. 또한 초기균열크기, 균열 형상비와 응력비의 변화에 따른 3차원 피로균열진전 해석 결과와 피로시험결과를 비교하였다. 피로균열진전 해석결과, 피로균열 진전속도와 응력확대계수와의 관계에서 피로시험과 유사하게 나타남을 확인하였으며, 면외거셋 용접이음의 피로수명을 추정할 수 있음을 확인하였다.