• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.15 no.6
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• pp.58-64
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• 2001

This paper is described about design and manufacture of the LVI tester and the model transformer. And we develope the analysis technology of the LVI test with using the developed LVI tester and the model transformer. The LVI tester is consisted of a main body, terminal boxes and cables. It is estimated that the tester has output characteristic to match ANSI specification. The winding deformation models are made of model transformer having tapes and we discuss about the analysis technology of LVI test using the tester and the model transformer.

• Journal of the Korean Geotechnical Society
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• v.19 no.5
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• pp.335-342
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• 2003

The method of measuring ground deformation modulus, in situ-testing has the disadvantage where the exam number is limited because it needs counter weight and a lot of measurement times. Recently, it has supplemented this problem and the equipments by which measurement can be made quickly are developed and applied in field., That is Falling Weight Deflectometer(FWD), Light Drop Weight Tester(LDWT), Geogauge. Light Drop Weight Teste.(LDWT) is introduced firstly in the name of ‘a lightweight fall circuit tester for a railroad public corporation’ by KTX. Since KTX introduced LDWT, a number of research organizations have used LDWT to find out domestic standard for quality management of base ground. In this study we used ZFG 02 which was manufactured by Stendal in Germany and measured the dynamic deformation modulus in soil box and in-situ. And we analyzed the correlation of the dynamic deformation modulus with static deformation modulus based on plate test in the same ground.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.2
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• pp.350-355
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• 2016

This research aims to evaluated the structure improvement and new product development of valve tester. A valve tester was redesigned for structure improvement and new product development using 3-D design program CATIA. In addition, behavior analysis was conducted on the modeled valve tester using the ANSYS program. The total deformation, stress and strain were obtained by the internal pressure change. This result was applied to the new product development of valve tester.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.865-868
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• 2002

This study investigated the shape deformation of ball projectile(5.56mn) under the low energy impact by the use of the drop weight impact tester. ball projectile(5.56mm) consisted of the copper face with a lead core. The impact conditions were changed with the variations of the mass and the drop height of the impact tup. Shape deformation of ball projectile(5.56mm) after low velocity impact was measured using a video microscope and CCD camera. The test result showed that impact energy by changing of drop height of the impact tup affected shape deformation of ball projectile(5.56mm). So, it is important to study the relativity between shape deformation of ball projectile(5.56mm) and ballistic protection of plate(such as hybrid composite laminates) under the high velocity impact.

• Journal of Sensor Science and Technology
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• v.28 no.1
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• pp.58-63
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• 2019

This research aims at designing a diaphragm made of SUS316L stainless steel for ultra high pressure sensors and evaluating its performance with a PZT driven deformation tester instead of high pressure chamber testing up to 100 MPa. Finite element method analysis indicates that the optimum thickness of a flat diaphragm is 1.5 mm not only to secure safety of sensors up to 100 MPa but also to enhance displacement measuring sensitivity. For this thickness, the maximum displacement at the center of the diaphragm is $5.3{\mu}m$. The PZT actuator must offer a force of 1,669 N to create a pressure of 100 MPa at the diaphragm surface in order to obtain a displacement of $5.3{\mu}m$. The performance evaluation by the PZT driven tester demonstrates nearly the same results as the same results as the sensors tested in the ultra high pressure chamber.

• International Journal of Highway Engineering
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• v.11 no.1
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• pp.135-144
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• 2009

The purpose of this study is to develop a simple and rational crack evaluation system using Marshall tester. Fracture energy were used as a parameter to evaluate the crack resistance of asphalt mixtures. Marshall tester basically measures the vertical deformation obtained from the linear variable differential transformer(LVDT) attached on the specimen's exterior, which can cause a measurement error due to the local deformation near the loading head. Therefore, the validity of the measurement system of Marshall tester should be tested to use it in calculation of fracture energy. Two types of indirect tensile strength tests were performed using four types of asphalt mixtures at two temperature conditions. From the tests, it was shown that local deformation near the loading head had not occurred before a specimen was fractured, so that it did not cause the measurement error of fracture energy. And also from the statistic analysis, the coefficient of variation of vertical deformation measurements obtained on specimen's exterior is less than 15%. Thus, vertical deformation measurements obtained on the specimen's exterior can be used in crack evaluation system using Marshall tester.

• Journal of Ocean Engineering and Technology
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• v.6 no.1
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• pp.87-95
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• 1992

Recently, the robot actuator worked by the driving recovery-force of the thermo elastic martensitic transformation of shape memory alloys(SMA) has been studied. In general, such a SMA actuator necessitates a number of cyclic repeated motion, so that the investigation of gradual decrease of recovery force with repeated motion cycle as well as the prevention of such a degradation of shape memory effect(SME) are very important for the actual use of a robot actuator. However, such research and discussions about the degradation of SME are very few up to the present. Therefore, in this study, the characteristics of the cyclic deformation and degradation of SME of Ti-Ni alloy would be investigated and discussed in detail by current heat type fatigue tester, which is a newly designed fatigue tester by author. In addition, we will establish a new design concept for robot actuator from these result.

• Journal of the Korea Convergence Society
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• v.10 no.1
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• pp.149-154
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• 2019

High pressure valve tester used in industrial fields precise measurement gives inconvenience in precise measurement due to manually regulated pressures. In order to improve this inconvenience, the high pressure valve tester was designed by using CATIA and structural analysis of the designed high pressure valve tester was conducted and water leaking, total deformation, strain and stress were obtained by applying ANSYS. These results will be provided to develop new concepts of high pressure valve tester as initial data.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.5
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• pp.97-103
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• 2002

The assessment of the condition of a transformer winding which is suspected of having suffered short circuit damage can be difficult. Conventional test such as winding resistance, magnetic current or insulation resistance will only detect damage if a permanent electrical fault exists. Visual inspection of windings necessitates the removal of oil and in many cases only a very small proportion of the winding can be seen. We describe the characteristic of LVI test system and methods to detect the deformation of windings in the power transformers. As the front rise time of recurrent-surge generator pulse less than 1000 ㎱ and the peak value of pulse is about 500 V, we have the good results of detecting winding deformation in the LVI test of transformers.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.6
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• pp.711-721
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• 2009

This study proposed digital close-range photogrammetric technique to measure deformation of I-plate-girder bridge. To compare deformation-measurement using the proposed method, a loading tester is used in the same time. As results, deviations of measuring values between the two methods range from 1mm to 2mm, and we could find-out simultaneously deflection and torsion of I-plate girder by repeated load of train. Then this study verified a measuring feasibility of I-plate-girder deformation by the proposed method. This may be alternative method of precise-stability inspection and manpower inspection.