• Journal of the Korea Concrete Institute
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• v.27 no.1
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• pp.11-20
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• 2015

An unbonded post-tensioned anchor using a 15.2 mm diameter 7-wire strand was developed based on finite element analysis and experimental testing. In order to evaluate its performance, static load tests and load transfer tests were conducted following KCI-PS101. The static load tests and additional strand tensile tests confirmed that the developed anchor had a capacity more than nominal tensile strength of a 7-wire strand without any damage or deterioration. According to the result of load transfer tests for many different reinforcing details, specimens with no additional reinforcing bars sustained at least 1.64 times the nominal tensile strength of the strand.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.185_186
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• 2009

전력산업분야는 스마트그리드 표준체계 및 고도화된 정보 통신 인프라의 도입과 분산전력 등에 대한 신기술 도입에 의해서 급격한 변화기를 맞이하고 있다. 현재 미국과 EU에서는 세계시장을 겨냥해서 스마트그리드의 국제표준화를 주도하고 있으며, 제3세계에서는 전력 설비 시장의 지속적 성장이 예상되고 있다. 이에 국내에서도 국제 경쟁력 확보 및 신성장동력 창출을 목표로 K-Grid 구성을 위한 연구가 진행 중이다. K-Grid 시험평가를 위해서는 전력체계의 운영망과 별개의 시험망 구성이 필요하며, 그 시험망을 통한 검증을 위해 시험망내 표준 규격의 통신환경의 설계 및 기능검증은 매우 중요한 요소이다. 본 논문에서는 K-Grid 시험평가망 구성이후 평가를 위해 사용할 수 있는 주요 Component의 설계과정 중의 일부인 MMS 기반의 Node간 통신 환경구성 및 기능검증을 위한 연구결과에 대해 설명한다.

• Geotechnical Engineering
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• v.9 no.4
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• pp.27-36
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• 1993

The drained and undrained behavior of pure silt was investigated experimentally. Special attention was given to the stress-strain behavior of silt prior to failure and behavior at failure under monotonic and cyclic loading. A pure silica flour was chosen to form samples with two different densities of D,=80%, eo=0.68 and D,=35%, eo=0.9. The isotropically consolidated samples were tested in the triaxial testing device under monotonic undrained, drained compression and extension conditions. Also samples were tested under cyclic undrained condition. Based on the experimental results. it was qualitively identified that the overall behavior of silt is similar to that of sand. When compared with clay, silt shows a significantly different behavior due to its dilatant nature under both the monotonic and cyclic shear loadings.

• Magazine of the Korea Concrete Institute
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• v.9 no.3
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• pp.137-147
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• 1997

Interface shear strength of' concrete under static loading and deterioratiion of interface strength by fatigue loading in shear were experimentally investigated using composite beam test specimens. Thirteen beams were constructed. Five composite beams were tested statically until interface delaminations were observed in the static tests. Seven composite beam and one monolithically cast beam were subjected to two to three million cycles of fatigue load. Test variables were interface roughness, interface shear reinforcement, and presence of interface bond. The average interface shear strength of the composite beams with bonded-rough interface was 6, 060 kPa. No interface delamination was observed after cycling for the composite beams with bonded - rough interface and interface bond was not influenced by repeated application of the shear stress of 2.000 kPa(about 1/3 of the static interface shear strength). Smooth interface and unbonded-rough interface with shear reinforcement deteriorated under repeated shear loading.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.41-42
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• 2012

• Journal of Biomedical Engineering Research
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• v.23 no.1
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• pp.17-26
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• 2002

The purpose of this study was to investigate the important Parameters of the Pedicle screw by estimating the mechanical characteristics of screws under static and dynamic loads. Methodology for estimating Parameters under static load was proposed. It was also shown that the fatigue life of the one-level system could be increased by changing the shape of screws. Load parameters of the single pedicle screw were friction force. bending moment. and holding force. The test results of the one-level system could be inferred from teat results of the sin91e screw under bending force Fatigue life of the one-level system with flexible rod was longer than that of the upper Part test without rod . Considering the drop of flexibility of the rod due to muscles and ligament, fatigue life of the one-level system could be estimated b? that of the single screw.

• Journal of the Society of Naval Architects of Korea
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• v.38 no.4
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• pp.75-82
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• 2001

Static loadings on ship structure induced either by water pressure before service such as a tank test and ballasting or by cargo pressure during first laden voyage cause relatively much greater stress than dynamic loadings induced by wave. With these static pre-loadings, the initial residual stresses around welded joint, where fatigue strength is concerned(in most cases, where stress concentration occurs) are expected to be shaken-down in a great extent by the elasto-plastic deformation behavior of material. Therefore, it is more resonable to assess the fatigue strength of ship structure with S-N data which have taken into account the effect of shaken-down residual stresses(re-distributed stresses) on the fatigue strength. In this research work, the re-distribution of residual stresses by the tensile pre-loading is measured using an ordinary sectioning method for specimens of padding plate weldment. Fatigue tests are performed also to evaluate the fatigue strength of the both as-welded and pre-loaded specimens.

• Proceedings of the Korean Society of Computer Information Conference
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• 2010.07a
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• pp.43-46
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• 2010

전력산업분야는 스마트그리드 표준체계 및 고도화된 정보통신 인프라의 도입과 보안 그리고 분산전력 등에 대한 신기술 도입에 의해서 급격한 변화기를 맞이하고 있다. 현재 미국과 EU에서는 세계시장을 겨냥해서 스마트그리드의 국제표준화를 주도하고 있으며, 제3세계에서는 전력설비 시장의 지속적 성장이 예상되고 있다. 이에 국내에서도 국제 경쟁력 확보 및 신성장동력 창출을 목표로 연구가 진행 중이다. 전력체계의 운영망과 별개의 시험망 구성이 필요하며, 그 시험망을 통한 검증을 위해 시험망내 표준규격의 통신환경의 설계 및 기능검증은 매우 중요한 요소이다. 본 논문에서는 시험평가망 구성이후 평가를 위해 사용할 수 있는 주요 Component의 설계과정 중의 일부인 IEC 61850기반의 MMS 통신 환경구성 및 기능검증을 위한 연구결과에 대해 설명한다.

• Journal of Aerospace System Engineering
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• v.15 no.1
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• pp.80-85
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• 2021

In this study, for conducting a static load test of an external fuel tank used for an aircraft, the flight load acting on the external fuel tank was converted to the test load and the suitability of the converted test loads was confirmed. In order to calculate the test load from the flight load, the external fuel tank was divided into several sections. Shear load, moment by unit shear load, and unit moment were calculated for each section. Test loads for each section were then calculated by computing the shear load, the moment of each section, and flight load condition. In actual static load tests, it might not be possible to impose the test load in the calculated position due to physical constraints. Therefore, after determining positions in which the load could be imposed in the actual test, the test load calculated for each section was redistributed to selected positions. Finally, a test load plan was established by applying a whiffle tree to enhance the efficiency of the test performance while making it easier to operate the actuator. The reliability of the test load plan was verified by comparing it with flight load conditions.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.2
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• pp.115-121
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• 2002

This report summarized the static test of the rudder system for the KTX-1 basic trainer. The test loads are applied up to the limit and ultimate loads in a stepping sequence. Test loads and test results matt the strength and stiffness requirements of the rudder control system.. Using #004 full scale structure test airframe.