• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.4
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• pp.53-60
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• 2019

In this study, a method for updating the finite element model of bridges with genetic algorithm using static displacement were presented, and verified this method using field test data for PSC girder bridge. As a field test, static load test and pseudo-static load test were conducted, and updated the finite element model of test bridge using each test data. Finally, evaluated the bridge load carrying capacity with updated model using pseudo-static load test's displacement data. To evaluate the bridge load carrying capacity, KHBDC-LSD, KHBDC and AASHTO LRFD's live load model were used, and compared the each results.

• 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.

• Journal of the korean Society of Automotive Engineers
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• v.3 no.1
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• pp.32-37
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• 1981

모든 차형을 간단한 이상형으로 가정하여 그들을 수치적인 값으로 비교할 수 있다면 승용차 차 체의 설계상 매우 큰 도움이 될 것이다. 실제로 새로운 모델의 차가 개발되었을 때에는 다음과 같은 이유 때문에 그 prototype body에 대한 정적 시험이 실시되고 있다. 1) 조기에 설계의 문제점이나 차체의 주결함을 발견할 수 있어 시간과 경비를 절약할 수 있다. 2) 계속적인 정적 시험을 통하여 구조적으로 만족할 만한 road car를 만들 수 있다. 3) 과설계를 방지하여 차체의 경량화에 기여하고, 최적설계의 개발을 위한 길을 제시해 준다. 차체에 대한 정적 시험은 위와 같은 이유 때문에 발전되어 왔으며, 정적 시험의 효과를 ㅊ대로 하기 위하여 그것은 순수한 공학적 원리에 기초를 두어 실제의 사용조건과 충분히 일치되는 시 험으로서 고안되었다. 차체구조는 그 사명의 다양성뿐만 아니라 제작, 개수에 상당한 노력과 시 간이 필요하기 때문에 조기에 문제점을 발견하여 결함을 제지하지 않으면 안된다. 구조체로서의 많은 필요조건 중에서 특히 중요시되는 것은 강도, 강성 및 내구성이다. 그 때문에 차체의 강도, 강성시험은 이론적인 해석(탄성학, 구조역학, 강도학 등)에 앞서 여러가지 방법이 개발되어 왔 으며, 여기에서는 그 중 가장 대표적인 방법인 비틀림시험(torsion test)과 굽힘시험(bending test) 에 관하여 Pony 4-door Sedan 차체의 시험 결과를 토대로 하여 기술하고자 한다.

• Korean Journal of Materials Research
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• v.7 no.11
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• pp.974-980
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• 1997

SiC$_{p}$/AI 합금 복합재료에 있어서 동적 및 정적파괴인성시험을 실시하고 파괴거동에 미치는 부하조건의 영향을 검토하였다. 동적파괴인성시험은 CAI시스템을 이용하여 1.5m/sec의 부하속도로 실시하였고, 정적파괴인성시험은 만능시험기를 이용하여 0.3 mm/min의 부하속도로 실시하였다. 또한 파괴과정을 명확히 해석하기 위하여 동적부하조건에 대해서는 stop block법을, 정적부하조건에 대해서는 복수시험편법을 이용하였다. 균열의 발생 및 성장은 부하조건에 의해 크게 영향을 받으며, 변위량에 대한 균열의 발생은 정적부하조건에서 더 빨리 일어나고, 균열의 성장은 동적부하조건에서 더 급격하다. 또한 부하조건은 파괴의 형태에도 크게 영향을 미치며, 동적부하조건하에서는 정적부하조건하에 비하여 균열이 입자부분(입자의 파단 또는 박리)을통과해 가는 경향이 크고 비교적 많은 편향을 반복해서 진행해 가지 때문에 파괴인성치도 크다.다.

• Journal of the Korean Geotechnical Society
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• v.22 no.10
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• pp.151-163
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• 2006

This paper presents the interrelationship between undrained static and cyclic shear behavior. Laboratory works were performed through the undralned static and cyclic triaxial test using Nak-Dong River sand. And static triaxial test involved the triaxial extension test for comparison with cyclic shear behavior Cyclic triaxial test was performed with a variety of combination conditions of initial static shear stress $(q_{st})$ and cyclic stress $(q_{cy})$. In this result, the stress path of cyclic shear behavior was correspondent with static shear behavior passing the critical stress ratio (CSR) line because of the development of flow deformation. After that, a failure occurred according to failure line (FL) of static shear behavior. The stress path of cyclic shear behavior showed essentially the same with static shear behavior, although it appears a little different in test method.

• Journal of the Korean Society for Railway
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• v.18 no.1
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• pp.33-42
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• 2015

The vertical static stiffness of rail pads or baseplate pads, which are important components in rail fastening systems for track safety, is a key factor to determine the total track stiffness and a guideline of quality control in the manufacturing process. The vertical static stiffness can be checked by laboratory testing: test methods are EN 13146-9 and KRS TR 0014, which are widely used in the railway field. In this paper, to correct some problems, namely the preloading step, the unloading level, and the holding time in the loading program in the vertical static stiffness test of EN 13146-9 and KRS TR 0014, domestic and foreign test standards of pads were analyzed and then certain schemes for a vertical static stiffness test were proposed. To assess the reliability of the proposed schemes, the vertical static stiffness tests were performed with 4 pads and the validity of the test results was estimated.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.8
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• pp.780-788
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• 2009

AE technique was applied to the static structural test of the composite wing structure to evaluate the structural integrity and damage. During the test, strain and displacements measurement technique were used to figure out for static structural strength. AE parameter analysis and source location technique were used to evaluate the internal damage and find out damage source location. Design limit load test, the 1st and 2nd design ultimate load tests and fracture test were performed. Main AE source was detected by an sensor attached on skin near by front lug. Especially, at the 1st design ultimate test, strain and displacements results didn't show internal damage but AE signal presented a phenomenon that the internal damage was formed. At the fracture test, AE activities were very lively, and strain and displacements results showed a tendency that the load path was changed by severe damage. The internal damage initiation load and location were accurately evaluated during the static structural test using AE technique. It is certified from this paper that AE technique is useful technique for evaluation of internal damage at static structural strength test.

• Aerospace Engineering and Technology
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• v.1 no.2
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• pp.32-44
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• 2002

This paper contains the information that describes the test fixture design and technology for full-scale airframe static test. Obtained technologies consist of determination of design load for test fixture, design technique for loading system, counterbalance system, positioning system of test article, test equipment and overload protection method. Full-scale airframe static test of advanced jet trainer was implemented using test fixture which are applied these technique.

• Korean Journal of Materials Research
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• v.8 no.6
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• pp.565-570
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• 1998

SiCp/6061AI 복합재료의 파괴인성을 평가하기 위하여 정적파괴인성에 대해서는 복수시험편법을, 동적파괴인성시험에 대해서는 stop block법을 실시하였다. 주균열은 예비균열의 선단에서 시험편두께방향 전역에 걸쳐서 일시에 발생하는 것이 아니고, 균열발생의 초기단계에서 국부적으로 형성된 균열이 시험편두께방향으로의 균열의 확장을 완료한 후 주균열로 이행해 간다. 정적 및 동적시험에서 컴플라이언스변화율법에 의해 검출된 균열발생점은 균열확장의 완료점과 거의 일치하고 있기 때문에 본 재료의 파괴인성 결정에 유효하다. 본 재료에서 동적파괴인성치는 정적파괴인성치보다 크게 나타났다. 이것은 동적충격시 입자파괴에 의한 에너지의 흡수.분산효과와 균열진전경로의 큰 편향에 기인한다고 생각된다.

• Journal of the Korean Geosynthetics Society
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• v.18 no.1
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• pp.39-53
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• 2019

Bi-directional pile load test (briefly called 'BDH PLT') cannot be performed at loading levels where ultimate bearing capacity could be assessed in field, it is not possible to precisely determine both ultimate load and yield load and under loading. Since the load is transmitted separately to the skin and the end unlike the static pile load test (briefly called 'SPLT') and the direction of loading on the skin is opposite, such methods could have a result different from actual movements of shafts. In this study, three-dimensional finite element method (briefly called '3D FEM') analysis was conducted from results of the BDH PLT, made with barret piles, which were large-diameter cast-in-place concrete piles, and the calculated design constants were applied to the 3D FEM analysis of the SPLT to interpret them numerically and then, actual behaviors of cast-in-place concrete piles were estimated. First, using the results of the BDH PLT with cast-in-place concrete piles, behaviors of the piles made by loading upwards and downwards were analyzed to calculate load-displacement. Second, the design constants, calculated by the 3D FEM analysis and the back analysis, were applied on the 3D FEM analysis for the SPLT, and from these results, behaviors of the SPLT through the BDH PLT was analyzed. Last, the results of the 3D FEM analysis of the SPLT through the BDH PLT was expressed in relationships as {A ratio of bearing capacity of the SPLT and of the BDH PLT (y)} ~ {A ratio of reference displacement and pile circumference (x)}, and they were all classified by reference displacement at 10.0 mm, 15.0 mm, and 25.4 mm.