• Journal of the Korean Society of Industry Convergence
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• v.9 no.2
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• pp.155-160
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• 2006

합성상판을 시공하는 경우 교축방향에 분할된 저강판을 접합 일체화해야 한다. 본 논문에서는 강 콘크리트 합성상판을 대상으로 3종류의 배력철근 방향 이음구조를 제안하며, 보 공시체에 의한 정적 정점피로 실험한다. 그 결과 보의 피로실험 결과 저강판 혹은 고력볼트가 피로파단 하였으며, 3차원 FEM해석에 이음부의 휨 강성도 및 피로강도에 대해서 해석적으로 검토된다.

• Journal of Korean Society of Steel Construction
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• v.30 no.2
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• pp.97-104
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• 2018

The safety evaluation of horizontal and vertical bolted connection between PHC piles is presented. The numerical analysis model is constructed using the commercial finite element program, ABAQUS, in which 3D solid element is used to model all the connection devices. The actual bolted connection is idealized by the contact and tie condition given in ABAQUS. Through the finite element analysis, the compression, tensile, bending and shear behaviors of PHC pile connection were analyzed. The safety factor based on Von-Mises and yield stress was calculated for the safety evaluation of each connection devices.

• The Journal of Korean Academy of Prosthodontics
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• v.31 no.2
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• pp.271-300
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• 1993

The purpose of this study was to analyze the stress distribution at supporting bone according to the types of connection modality between implant and tooth in the superstrcture. This investigation evaluated the stress patterns in a photoelastic model produced by three different types of dental implants such as Branemark, Steri-Oss, IMZ and resin tooth using the techniques of quasi three dimensional photoelasticity. The teeth-supported bridge had a first molar pontic supported by second premolar and second molar as a control group. The implant and toothsupported bridge had a first molar pontic supported by second premolar and implant posterior retainer as an experimental group. Prostheses were mechanically connected to an adjacent second premolar by the rigid of nonrigid connection, Nonrigid connection used an attachment placed between the tooth-supported and fixture-supported component. The female(keyway) of attachment was placed on the distal end of the retainer supported by the tooth ; the male(Key) of attachment connected to the osseointegrated bridge was engaged into the keyway. All prostheses were casted in the same nonprecious alloy and were cemented and screwed on their respective abutments and implants. 16㎏ of vertical loads on central fossae of second premolar, first molar pontic, implant of second molar were applied respectively and 6.5㎏ of inclined load on middle buccal surface of first molar pontic was applied. The results were as follows : 1. Under the vertical load on the central fossa of first mloar pontic, the stress developed at the apex of tooth of implat was more uniformly distributed in the case of nonrigid connection than in the case of rigid connection. 2. Under the vertical load on the central fossa of first molar pontic, the stress developed around the cervical area of tooth of implant was larger in the case of rigid connection than in the case of nonrigid connection because the bending moment was more occured in the case of rigid connection than in the case of nonrigid connection. 3. Stress was more restricted to the loaded side of nonrigid connection than to that of rigid connection 4. Under the inclined load. The set screw loosening of implant was more easily occured in the case of nonrigid connection than in the case of rigid connection due to torque moment. 5. In the case of Branemark implant, the stress concentration in second premolar was larger and the stress developed around the cervical area of implant was lower than any other cases under the vertical load, because Branemark implant with the flexible gold screw was showed in incline toward second premolar by a bending moment. 6. The stress developed around the apex of tooth or implant was more uniformly distributed in the case of Steri-Oss implant with stiff screw than in the case of Branemark implant under the vertical load. But, the stress developed around the cervical area of the Steri-Oss implant was larger than that of any other implants because bending moment was occured by vertical migration of second premolar. 7. The stress distribution in the case of IMZ implant was similar to the case of natural teeth under small vertical load. But, the residual stress around the implant was showed to occurdue to deformation of IMC and sinking of screw under larger vertical load.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.10a
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• pp.173-178
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• 2002

Flat plate is susceptible to punching shear failure at the slab-column connection, which may cause catastrophic structural collapse. To prevent such brittle failure, strength and ductility of the connection should be ensured. However, since it is very difficult to experimentally simulate the actual load and boundary conditions of the flat plate system, it is not easy to obtain reliable information and data regarding to the strength and ductility of the flat plate-column edge connection. In the present study, numerical studies were performed for edge connections of continuous flat plate. The results were compared with the existing experiments, and the variations of bending moment, drift, effective width around the connection were investigated. Based on tile findings of the numerical studies, the disadvantages of current design methods were discussed.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.891-896
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• 2002

Flat plate is susceptible to punching shear failure at the slab-column connection, which may cause catastrophic structural collapse. To prevent such brittle failure, strength and ductility of the connection should be ensured. However, since it is very difficult to experimentally simulate the actual load and boundary conditions of the flat plate system, it is not easy to obtain reliable information and data regarding to the strength and ductility of the flat plate-column connection. In the present study, numerical studies were performed for interior connections of continuous flat plate. The results were compared with the existing experiments, and the variations of bending moment, shear, torsional moment around the connection were investigated. Based on the findings of the numerical studies, the disadvantages of current design methods were discussed.

• Structural Engineering and Mechanics
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• v.81 no.2
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• pp.117-129
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• 2022

This research evaluated the different types of deck to pier connections effects (one or two elastomeric bearing lines and rigid) on a concrete bridges. Three-dimensional bridge models behavior with different deck to pier connections and different distances of two bearing lines were studied under the service load. Also, the detailed connection system with two elastomeric bearing lines was modeled to evaluate the effect of changing distance between two-lines. Results indicated that the proper location of elastomeric bearings has a major impact on the transferring forces to the substructure. Double elastomeric bearing lines have a behavior between one line and rigid connections. Transferring bending moment to the substructure in two-lines is more than the corresponding value of the one line. Moreover, an increase in the distance of two-lines lead to a significant increase in the rotational stiffness of the connection, and an analytical solution was investigated for their relation. In fact, the semi-rigidity effect of this connection and its change due to the distance of bearings should be considered in the design process.

• Journal of Korean Society of Steel Construction
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• v.29 no.6
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• pp.423-434
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• 2017

In this paper a systematic numerical analysis is performed to obtain the hysteresis behavior of partially restrained top and seat angle connections subjected to cyclic loading. This connection includes superelastic shape memory alloy (SMA) angles and rods in order to secure the recentering capacities as well as proper energy dissipation effects of a CFT composite frame. The three-dimensional nonlinear finite element models are constructed to investigate the rotational stiffness, bending moment capacity and failure modes. A wide scope of additional structural behaviors explain the different influences of the connection's parameters, such as the various thickness of connection angles and the gage distance of steel and SMA rods.

• Structural Engineering and Mechanics
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• v.74 no.5
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• pp.657-670
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• 2020

Due to the high compressive and tensile strength of ultra-high performance concrete (UHPC), UHPC used in steel concrete composite structures provided thinner concrete layer compared to ordinary concrete. This leaded to the headed stud shear connectors embedded in UHPC had a low aspect ratio. In order to systematic investigate the effect of headed stud with low aspect ratio on the structural behaviors of steel UHPC composite structure s this paper firstly carried out a test program consisted of twelve push out specimens. The effects of stud height, aspect ratio and reinforcement bars in UHPC on the structural behaviors of headed studs were investigated. The push out test results shows that the increasing of stud height did not obviously influence the structural behaviors of headed studs and the aspect ratio of 2.16 was proved enough to take full advantage of the headed stud strength. Based on the test results, the equation considering the contribution of weld collar was modified to predict the shear strength of headed stud embedded in UHPC. The modified equation could accurately predict the shear strength of headed stud by comparing with the experimental results. On the basis of push out test results, bending tests consisted of three steel UHPC composite slabs were conducted to investigate the effect of shear connection degree on the structural behaviors of composite slabs. The bending test results revealed that the shear connection degree had a significantly influence on the failure modes and ultimate resistance of composite slabs and composite slab with connection degree of 96% in s hear span exhibited a ductile failure accompanied by the tensile yield of steel plate and crushing of UHPC. Finally, analytical model based on the failure mode of composite slabs was proposed to predict the ultimate resistance of steel UHPC composite slabs with different shear connection degrees at the interface.

• Steel and Composite Structures
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• v.32 no.1
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• pp.79-90
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• 2019

This study introduces new connections that connect the beam to the column with slit dampers. Plastic deformations and damages concentrate on slit dampers. The slit dampers prevent plastic damages of column, beam, welds and panel zone and act as fuses. The slit dampers were prepared with IPE profiles that had some holes in the webs. In this paper, two experimental specimens were made. In first specimen (SDC1), just one slit damper connected the beam to the column and one IPE profile with no holes connected the bottom flange of the beam to the column. The second specimen (SDC2) had two similar dampers which connected the top and bottom flange of the beam to the column. Cyclic loading was applied on Specimens. The cyclic displacements conditions continued until 0.06 radian rotation of connection. The experimental observations showed that the bending moment of specimen SDC2 increased until 0.04 story drift. In specimen SDC1, the bending moment decreases after 0.03 story drift. Test results indicate the high performance of the proposed connection. Based on the results, the specimen with two slit damper (SDC2) has higher seismic performance and dissipates more energy in loading process than specimen SDC1. Theoretical formulas were extended for the proposed connections. Numerical studies have been done by ABAQUS software. The theoretical and numerical results had good agreements with the experimental data. Based on the experimental and numerical investigations, the high ductility of connection is obtained from plastic damages of slit dampers. The most flexural moment of specimen SDC1 occurred at 3% story drift and this value was 1.4 times the plastic moment of the beam section. This parameter for SDC2 was 1.73 times the plastic moment of the beam section and occurred at 4% story drift. The dissipated energy ratio of SDC2 to SDC1 is equal to 1.51.

• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.3
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• pp.269-281
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• 2008

Fatigue or overload can result in mechanical problems of implant components. The mechanical strength in the implant system is dependent on several factors, such as screw and fixture diameters, material, and design of the fixture-abutment connection and abutment. In these factors, the last rules the strength and stability of the fixture-abutment assembly. There have been some previous reports on the mechanical strength of the fixture-abutment assembly with the compressive bending test or short-term cyclic loading test. However, it is restrictive to predict the long-term stability of the implant system with them. The purpose of this study was to evaluate the influence of the design of the fixture-abutment connection and abutment on the mechanical strength and failure mode by conducting the endurance limit test as well as the compressive bending strength test. Tests were performed according to a specified test(ISO/FDIS 14801) in 4 fixture-abutment assemblies of the Osstem implant system: an external butt joint with Cemented abutment (group BJT), an external butt joint with Safe abutment (group BJS), an internal conical joint with Solid abutment (group CJO), and an internal conical joint with ComOcta abutment (group CJT). The following conclusions were drawn within the limitation of this study. Compressive bending strengths were decreased in order of group BJS(1392.0N), group CJO(1261.8N), group BJT(1153.2N), and group CJT(1110.2N). There were no significant differences in compressive bending strengths between group BJT and group CJT(P>.05). Endurance limits were decreased in order of group CJO(600N), group CJT(453N), group BJS(360N), and group BJT(300N). 3. Compressive bending strengths were influenced by the connection and abutment design of the implant system, however endurance limits were affected more considerably by the connection design.