• 한국강구조학회 논문집
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• 제16권6호통권73호
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• pp.747-757
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• 2004

강-콘크리트 합성보에서 강과 콘크리트 사이의 불완전 합성거동은 완전 합성보에 비해서 처짐이 매우 증가하게 된다. 특히, 춤이 깊은 데크 및 속 빈 PC슬래브 등을 사용한 매립형 합성보의 경우, 자체의 형상에 기인하여 처짐에 매우 취약하다. 본 연구에서는 기존 연구에서 유도한 슬립효과를 고려한 처짐 계산법 및 실험으로부터 구한 하중-슬립 관계로부터 매립형 합성보의 전단부착응력 및 슬립에 의한 추가 처짐 값을 제시하였다. 매립형 합성보의 처짐에 미치는 슬립의 영향은 완전 합성보의 강성 값에 비해 약 30%정도 감소함을 알 수 있었다. 또한, 실험 및 예측 값의 비교결과, 6%내외의 오차로 비교적 좋은 결과를 나타내었다.

• 콘크리트학회논문집
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• 제20권1호
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• pp.51-58
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• 2008

해석적 방법에 의한 지진 취약성 분석 (fragility analysis)은 입력 거동과 응답 특성의 불확실성을 고려하기 위해 임의화된 확률 변수들 (randomized response variables)로 인하여 해석 과정에 상당한 노력과 시간이 요구된다. 본 연구에서는 구조물의 기본적인 특성인 강성, 강도 및 연성 능력에 따라 지진 취약도 곡선을 바로 도출할 수 있는 새로운 방법을 제안한다. 광범위한 구조물을 대표할 수 있는 일반화된 단자유도계의 동적 해석 결과로부터 로그 정규 취약성 곡선의 도출에 필요한 파라미터를 응답 데이터베이스에 저장한다. 이를 이용함으로써 구조물의 기본적인 특성 (강성, 강도, 연성 능력)만으로 동적해석 과정을 수행하지 않고도 한계상태 취약성 곡선을 도출할 수 있다. 본 논문의 적용 사례를 통해서 제안된 방법이 지진 취약성 곡선을 얻는데 매우 효율적임을 확인 할 수 있다.

• 대한기계학회논문집A
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• 제26권5호
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• pp.960-968
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• 2002

In this research, the effects of fiber stacking sequence on damage behaviors of FML(Fiber Metal Laminates) subject to indentation loading. SOP (Singly Oriented Ply) FML and angle ply FML were fabricated to study fiber orientation effects and angle ply effects. FML were fabricated by using 1050 aluminum laminate and carbon/epoxy prepreg. To increase adhesive bonding strength, Al laminate was etched using FPL methods. The static indentation test were conducted by using UTM under the 2side clamped conditions. During the tests, load and displacement curve and crack initiation and propagation behaviors were investigated. As fiber orientation angle increases, the crack initiation load of SOP FML increases because the stiffness induced by fiber orientation is increased. The penetration load of SOP FML is influenced by the deformation tendency and boundary conditions. However, the macro-crack of angle ply FML was initiated by fiber breakage of lower ply because angle plies in Angle ply FML prevents the crack growth and consolidation. The Angle ply FML has a critical cross-angle which prevent crack growth and consolidation. Damage behavior of Angle ply FML is changed around the critical cross-angle.

• 대한인간공학회지
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• 제27권2호
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• pp.83-89
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• 2008

Study was developed the metallic plate for fixation in the femur fracture and plates has a firm place in fracture treatment. This plates can be stabilized for fracture fixation as well as biological and dynamical device. The device's designation and sizing has a optimization with bending structural stiffness and strength, known meaning that is reliable regardless of the plate by the short type and long type. The bending strength of the curved metallic long plate has to evaluate a 11,000N and the bending strength of the curved metallic short plate has to evaluate a 6,525N. This see the X-ray image of bending angle made certain of 15$^{\circ}$ at number 2 and same 82.87$^{\circ}$ at number 2, 4, 5, 7, 8, 9, 10 by outside angle, and confirmed 25.26$^{\circ}$ at number 3, 3.68$^{\circ}$ at number 6, 15.64$^{\circ}$ at number 9 by inside angle. This study shows that keep up the metallic plate for fixation in the femur fracture through X-ray Image and the device can be used to support Revision case of Hip Implant and to use a case of Hip screw compression of Hip Neck Fracture. Short plate have a wrapping of femur and long plate have to preserve a pole of femur.

• Structural Engineering and Mechanics
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• 제73권6호
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• pp.613-620
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• 2020

The research study is focuses on a form of all-bolted joint with the external ring stiffening plate in the prefabricated steel structure. The components are bolted at site after being fabricated in the factory. Six specimens were tested under cyclic loading, and the effects of column axial compression ratio, concrete-filled column, beam flange sub plate, beam web angle cleats, and spliced column on the failure mode, hysteretic behavior and ductility of the joints were analyzed. The results shown that the proposed all-bolted joint with external ring stiffening plate performed high bearing capability, stable inflexibility degradation, high ductility and plump hysteretic curve. The primary failure modes were bucking at beam end, cracking at the variable section of the external ring stiffening plate, and finally welds fracturing between external ring stiffening plate and column wall. The bearing capability of the joints reduced with the axial compression ratio increased. The use of concrete-filled steel tube column can increase the bearing capability of joints. The existence of the beam flange sub plate, and beam web angle cleat improves the energy dissipation, ductility, bearing capacity and original rigidity of the joint, but also increase the stress concentration at the variable section of the external reinforcing ring plate. The proposed joints with spliced column also performed desirable integrity, large bearing capacity, initial stiffness and energy dissipation capacity for engineering application by reasonable design.

• Geomechanics and Engineering
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• 제15권5호
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• pp.1101-1111
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• 2018

This study aims to present accurate soil modeling and validation of a single roadside guardrail post as well as a single concrete pile installed near cut slopes or compacted sloping embankment. The conventional Winkler's elastic spring model and p-y curve approach for horizontal ground cannot directly be applied to sloping ground where ultimate soil resistance is significantly dependent on ground inclination. In this study, both grid-based 3-D FE model and particle-based SPH (smoothed particle hydrodynamics) model available in LS-DYNA have been adopted to predict the static behavior of a laterally loaded guardrail post. The SPH model has potential to eliminate any artificial soil stiffness due to the deterioration of the node-connected Lagrangian soil mesh. For this purpose, this study comprises two parts. Firstly, only 3-D FE modeling has been tested to show the numerical validity for a single concrete pile in sloping ground using Mohr-Coulomb material. However, this material option cannot be implemented for SPH elements. Nevertheless, Mohr-Coulomb model has been used since this material model requires six input soil data that can be obtained from the comparative papers in literatures. Secondly, this work is extended to compute the lateral resistance of a guardrail post located near the slope using the hybrid approach that combines Lagrange FE elements and SPH elements by the suitable node-merging option provided by LS-DYNA. For this analysis, the FHWA soil material developed for application to road-base soils has been used and also allows the application of SPH element.

• Journal of Acupuncture Research
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• 제21권2호
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• pp.183-203
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• 2004

Objective : Tension-type headache is the most common headache. The objective of this study is to find the clinical manifestation of tension-type headache and correlation with autonomic bioelectric response. Methods : This observation was carried out on 60 patients with tension-type headache. We used headache questionnaire and the Autonomic Bioelectric Response recoder(ABR-2000) for this study. Results : 1. Distribution of sex & age : male : female=5 : 7, 50s&60s group (28.3%) 2. Duration of onset : over 5years(50%), over one years(83.4%) 3. Causes of illness : stress(58.3%), severe fatigue(53.5%), tension(33.3%) 4. Time of attack : irregular(56.7%), day time(16.7%) 5. Pattern of pain: heavy(31 people), stiffness of occipital region (27 people) tightening around the head(25 people) 6. Curve : 40%, 56.7%, 35.0% SL(Slope low) at peak 1, 2, 3/ SH&SI not found 7. Regulation : 16.7% RR(Regulation reverse) at peak 1, 25% RH(Regulation high) at peak 2, 15% RR(Regulation reverse) at peak 3 8. Graph : Activity-60.0%, 70.0%, 63.3% lowered reaction(L, LR, L!) at peak 1, 2, 3 Reactivity-83.3%, 95.0%, 93.3% lowered reaction at peak 1, 2, 3 Conclusion : We find tension-type headache has remarkable relativeness with autonomic bioelectric response.

• 대한기계학회논문집A
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• 제40권4호
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• pp.415-422
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• 2016

충격 가속도가 기계 시스템에 가해지면 시스템의 기능 저하 및 파손이 발생할 수 있다. 이러한 문제점을 방지하기 위하여 감시 정찰 비행기에 장착되는 짐발 구조 시스템은 설계 사양으로 MIL-STD-810G 충격 규격을 반드시 만족해야 한다. 일반적으로 비행기에서 전달되는 충격을 완화하기 위하여 시스템의 기초부에 방진고무가 설치된다. 고무는 비선형 하중-변형 관계를 가지므로 정확한 시스템의 충격 응답 계산이 어렵다. 이를 해결하기 위하여 비선형 특성을 2개의 선형으로 근사화하여 기초부에 충격 가속도를 받는 시스템의 동적 해를 유한요소법으로 구하였다. 그리고 동일한 조건에서 행한 실험과 비교 결과 제안된 해석 방법이 강성과 감쇠에서 비선형성을 갖는 방진고무가 포함된 짐발 구조 시스템의 동적 해석에도 유용함을 입증하였다.

• 한국항공우주학회지
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• 제41권7호
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• pp.561-568
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• 2013

7,000lb 급 헬리콥터를 위한 무베어링 로터 허브 시스템을 설계한 후, 무베어링 로터 허브 시스템의 주요 구성품 중 하나인 유연보에 대해 요구수명 8,000시간을 만족하는지 확인하기 위한 피로해석을 수행하였다. 2차원 탄성 보 모델에 대한 단면 구조해석 방법을 적용하였으며, 정적구조해석을 통해 피로손상에 취약할 것으로 예상되는 두 단면에 대한 피로해석을 수행하였다. 구조해석을 위해 VABS를 사용하여 유연보 단면 형상에 대한 인장, 굽힘 및 뒤틀림 강성을 계산하였고, wohler equation을 적용하여 유연보를 구성하는 두 가지 복합재 소재에 대한 S-N 곡선을 생성하였다. CAMRAD II를 통해 무베어링 로터 시스템의 하중해석을 수행하였으며, 하중해석 결과를 HELIX/FELIX 표준하중 스펙트럼에 적용하여 무베어링 로터 시스템의 하중 스펙트럼을 생성한 후, 이를 통해 피로해석을 수행하였다.

• 동의신경정신과학회지
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• 제12권2호
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• pp.37-51
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• 2001

The clinical study was carried out the 43 patients with Depression who were treated in Department of Neuropsychiatry, College of Oriental Medicine, Dae Jeon University from 22 February 2000 to 14 November 2001. The results were summarized as follows. 1. The ratio of male and female was 10:33, 60's(32.6%) was frequent, no inducing factor(38.3%) was seen in a lot of cases and many patients came to our hospital by way of west-neuropsychiatry(56.8%). 2. The period of clinical history was frequent from 3 to 10 years(23.2%), the most frequent preceding disease was cardiovascular systemic disease(18.4%). 3. The main clinical symptoms were apprehension alpitation(13.4%), anorexia(9.8%), headache nuchal region stiffness(9.8%), general body weakness(6.5%), chest discomfort(6.5%), dizziness(5.7%), febris(5.3%) and constipation(5.3%). 4. The patient's tongue aspect had pink tongue and empty fur(32.6%) and pulse type had thin and deficient pulse(39.5%). The prescription drugs were Chunggansoyo-san(30.0%), purging liver and alleviating depression to regulate qi, and Guibiondam-tang(15.8%) eliminating phlegm, cooling pericardium and warming gallbladder. 5. The curve was within normal range at Psychoneural system(81.4%), and Visceral system(90.1%). 6. The regulation was Normal(48.1%), RL(27.9%), RR(20.2%) at Psychoneural system and Normal(45.9%), RL(28.5%), RR(20.3%) at Visceral system. 7. Activity and Reactivity had much lower response at 1th, 2th, 3th, 4th, 7th SANGHAN, Polalization had much higher response at 1th, 4th, SANGHAN and much lower response at 2th, 3th, 7th SANGHAN.