• Computers and Concrete
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• 제10권4호
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• pp.361-377
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• 2012

Four Reinforced Concrete (RC) single span structural walls having various opening sizes and locations were constructed and tested under lateral reversed cyclic loading at the structural laboratory of Kyoto University. These specimens were scaled to 40% and represented the lower three stories of a six-storied RC building. The main purposes of the experimental tests were to evaluate the shear behavior and to identify the influence of opening ratios on the cracks distribution and shear strength of RC structural walls. The shear strength of the specimens was estimated by combining the shear strength of structural wall without openings and the reduction factor that takes into account the openings. Experimental and analytical results showed that the shear strength was different depending on the loading direction due to opening locations. A two-dimensional finite element analysis was carried out to simulate the performance of the tested specimens. The constructed finite elements model simulated the lateral load-drift angle relations quite well.

• Earthquakes and Structures
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• 제16권1호
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• pp.83-96
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• 2019

The seismic behavior of PRC coupling beam-hybrid coupled shear wall system is analyzed by using the finite element software ABAQUS. The stress distribution of steel plate, reinforcing bar in coupling beam, reinforcing bar in slab and concrete is investigated. Meanwhile, the plastic hinges developing law of this hybrid coupled shear wall system is also studied. Further, the effect of coupling ratio, section dimensions of coupling beam, aspect ratio of single shear wall, total height of structure and the role of slab on the seismic behavior of the new structural system. A fitting formula of plate characteristic values for PRC coupling beams based on different displacement requirements is proposed through the experimental date regression analysis of PRC coupling beams at home and abroad. The seismic behavior control method for PRC coupling beam-hybrid coupled shear wall system is proposed based on the continuous connection method and through controlling the coupling ratio, the roof displacement, story drift angle of hybrid coupled shear wall system, displacement ductility of coupling beam.

• Steel and Composite Structures
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• 제27권3호
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• pp.389-399
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• 2018

A perforated shear connector group is commonly used to transfer shear in steel-concrete composite structures when the traditional shear stud connection is not strong enough. The multi-hole perforated shear connector demonstrates a more complicated behavior than the single connector. The internal force distribution in a specific multi-hole perforated shear connector group has not been thoroughly studied. This study focuses on the load-carrying capacity and shear force distribution of multi-hole perforated shear connectors in steel-concrete composite structures. ANSYS is used to develop a three-dimensional finite element model to simulate the behavior of multi-hole perforated connectors. Material and geometric nonlinearities are considered in the model to identify the failure modes, ultimate strength, and load-slip behavior of the connection. A three-layer model is introduced and a closed-form solution for the shear force distribution is developed to facilitate design calculations. The shear force distribution curve of the multi-hole shear connector is catenary, and the efficiency coefficient must be considered in different limit states.

• 대한소아치과학회지
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• 제27권3호
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• pp.444-456
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• 2000

치아 교환시기에 발거된 치관이 건전한 유구치 상아질 표면을 One-Bottle 상아질 결합제인 Primer & Bond NT(DeTrey/Dentsply, Konstanz, Germany)와 Single Bond(3M Co. U.S.A.) 그리고 대조군으로 Scotchbond Multipurpose System(3M Co. U.S.A.)를 이용하여 각 제조자의 지침에 따라 처리하여 레진을 충전하고 광중합하였다. 1. 전단 결합 강도의 측정결과 Primer & Bond NT군인 1군, Single Bond군인 2군, 그리고 대조군으로 사용된Scotchbond Multipurpose System군인 3군의 순서로 1군에서 다소 높은 전단 결합 강도를 보였으나, 모든 군들간에는 통계적 유의차가 없었다(p>.05). 2. 주사 전자현미경 소견에서 1군 2군에서 서로 유사한 양상의 잘 형성된 혼화층이 관찰되었으며, 레진 테그와 측방 가지 또한 다수 관찰되었다. 반면 3군에서는 혼화층이나 측방가지의 형성이 1, 2군에 비해 다소 미약한 양상을 보였다.

• 한국추진공학회지
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• 제19권1호
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• pp.9-17
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• 2015

기본 유동 형상은 상대적으로 얇은 중간층이 연료와 공기 사이에 끼어있는 평행 2단 혼합층으로 구성되어 있다. 본 연구는 중간층의 두께 변화에 따른 연소 향상을 수치해석을 통해 조사하였다. 이 경우에, 난류 혼합층에서 열 방출에 의한 효과가 중요하다. 수치해석을 수행하기 위해 완전 보존적인 비정상 2차 시간 정확도의 하부 반복 기법과 2차 총 변화 억제 기법을 k-${\omega}$ 전단응력이동 모델이 결합된 유한체적법과 함께 사용하였다. 다음과 같이 3개의 경우에 대해 해석을 수행하였다. 연료와 공기로 구성된 단일 혼합층, 연료와 공기 사이에 불활성 기체층이 끼어있는 2단 혼합층, 그리고 연료와 공기 사이에 차가운 연료층이 끼어있는 2단 혼합층. 수치해석은 중간 기체층이 1, 2, 4 mm 인 경우에 대하여 수행되었다. 기체층의 총 두께는 4 cm이다. 불활성기체층이 2, 4 mm인 경우와 저온의 연료층이 4 mm인 경우에 단일 혼합층의 경우보다 연소영역이 확대된다.

• Advances in materials Research
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• 제12권3호
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• pp.243-261
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• 2023

This study aims to analyze the mechanical buckling behavior of a single-walled carbon nanotube (SWCNT) integrated with a one-parameter elastic medium and modeled as a Kerr-type foundation under a longitudinal magnetic field. The structure is considered homogeneous and therefore modeled utilizing the nonlocal first shear deformation theory (NL-FSDT). This model targets thin and thick structures and considers the effect of the transverse shear deformation and small-scale effect. The Kerr model describes the elastic matrix, which takes into account the transverse shear strain and normal pressure. Using the nonlocal elastic theory and taking into account the Lorentz magnetic force acquired from Maxwell relations, the stability equation for buckling analysis of a simply supported SWCNT under a longitudinal magnetic field is obtained. Moreover, the mechanical buckling load behavior with respect to the impacts of the magnetic field and the elastic medium parameters considering the nonlocal parameter, the rotary inertia, and transverse shear deformation was examined and discussed. This study showed useful results that can be used for the design of nano-transistors that use the buckling properties of single-wall carbon nanotubes(CNTs) due to the creation of the magnetic field effect.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2003년도 봄 학술발표회 논문집
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• pp.227-234
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• 2003

In this study, an equivalent continuum model for single wall carbon nanotube is proposed. The model links interatomic potentials and atom structure of a materials to a constitutive model on the continuum level. The Young's modulus and shear modulus were predicted by the model. The predictions were in good agreement with the prior experimental results available in the literatures. Also, the strain energy of the carbon nanotube was predicted as a function of the radius of the carbon nanotube.

• Journal of Welding and Joining
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• 제30권6호
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• pp.62-67
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• 2012

In this study, the bonding strengths of adhesively bonded joints are experimentally investigated. A series of lap-shear tests are conducted using single lap type adhesive joints. In order to analyse the joint fabrication factors that affected the bonding strength, the parametric tests are conducted with various thickness of adhesive, surface roughness and fillet of adhesive. In addition, for the comparative study with the welded joint, lap-shear tests using specimens with 2 welded sides and 4 welded sides are also carried out. The quantitative results of the strength analysis are summarized, and some proposals are made on setting up testing standards for adhesively bonded joints.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.267-270
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• 2005

The section of double-tee is considered as one of the most efficient type for flexure. However, the depth of it is bigger then that of other slab systems. The story height of it is also increased because the duct space is required under the double tee in addition to their net depth. Thus, a new modified double-tees with the nib length of 1.58m was suggested in this study. The story height of this one is reduced up to 450mm by including duct space under the nib at the ends of slab. The four ends of the modified two single tees were designed by strut-tie models. Shear tests were performed on them to verify the safety. The ultimate shear strengths of non-prestressed two specimens were larger than the design shear strength by strut-tie models. They were failed in ductile with many distributed flexural crackings. However, the other prestressed two specimens showed much stiffer behaviors, less deflection. and strength than those of prestressed.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.577-580
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• 2003

Stress state of chip formation zone is one of the main problems in metal cutting mechanics. In two-dimensional case this process is usually considered as consistent shears of work material along single of several shear surfaces. separating chip from workpiece. These shear planes are assumed to be trajectories of maximum shear stress forming corresponding slip-line field. This paper suggests new approach to the constriction of slip-line field, which Implies uniform compression in chip formation zone. On the base of given model it has been found that imaginary shear line in orthogonal cutting is close to the trajectory of maximum normal stress and the problem about its determination have been considered. It has been shown that there is a second central slip-line field inside chip, which corresponds well to experimental data about stress distribution on tool rake face and tool-chip contact length. The suggested model could be useful in solution of various problems of machining.