http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
소다라임유리에서 구형입자 충격손상에 미치는 가압조건의 영향
신형섭,오상엽 安東大學校 工業技術硏究所 2001 공업기술연구논문집 Vol.8 No.1
가압치구를 이용해 접촉압력을 가할 수 있는 실험장치를 개발하여 가압 구속조건이 구형입자 충격시 발생하는 충격손상의 영향을 조사하였다. 소다라임유리 (33×33×8mm)에 직경3mm인 WC와 Steel구를 각각 30~200m/s의 속도로 충격을 가하였다. 그리고 3가지 다른 조건, 즉 가압치구가 없는 경우, 가압치구가 있으며 압력 p=0㎫, p=200㎫ 를 가한 조건을 설정하였다. 입자충격으로 인하여 ring, radial 등과 같은 균열이 발생되었다. 시험편에 가한 접촉응력이 시험편 내부 응력장을 변화시켰다. 따라서 가압치구가 없는 시험편의 손상영역은 입자충격속도가 증가함에 따라 증가하였다. 200㎫의 접촉압력을 가한 시험편의 경우는 가압치구가 없는 경우에 비해 감소하였다. An experimental investigation was made, which comprise a pressing die, to evaluate the influence of pressing condition on the damage induced by a spherical impact. Steel and WC sphere in 3mm diameter impacted to soda-lime glass specimen with dimension of 33 x 33 x 8mm in the impact velocity range of 30m/s to 200m/s. Three different contact conditions were given for the impact damage evaluation, which are, the cases without pressing die, the cases of p=0㎫ and p=200㎫ with pressing die. The spherical impact had produced various kinds of damage such as ring cracks, cone cracks and radial cracks. The contact pressure applied to the specimen changed stress fields developed in the specimen which suppressed the structural bending of specimen and development of radial cracks. The extent of induced damage in the specimen with contact pressure of 200㎫ was reduced, as compared with the cases of without pressing die or with contact pressure of 100㎫.
아닐링처리에 따른 NbTi초전도 선재의 RRR거동에 미치는 피로손상의 영향
신형섭,오상엽 安東大學校 工業技術硏究所 2000 공업기술연구논문집 Vol.7 No.1
9본으로 구성된 Cu-Ni/NbTi/Cu 복합선재의 RRR에 대한 피로손상의 영향을 연구하기 위하여 상온에서 피로시험을 실시하고, 12K에서 잔류저항을 측정하였다. 피로시험은 아닐링열처리한 초전도 선재를 사용하였다. 피로시험시 소선간의 fretting이 발생한 가능성이 높았지만, 9본 Cu-Ni/NbTi/Cu 복합선재의 피로시험을 통하여 S-N선도를 구살 수 있었다. 피로시험후 NbTi소선의 저항을 측정한 결과, 아닐링한 선재의 RRR값이 처녀재보다 3배가 높았으나, 피로 반복수가 증가함에 따라 격자결함과 Cu안정화재 내부에 전위와 같은 손상의 누적 원인으로 RRR값이 감소하였다. In order to investigate how the fatigue damage influences on the RRR of a 9 strand Cu-Ni/NbTi/Cu composite cable, the fatigue test at room temperature and the residual resistivity measurement test at 12K were carried out. The annealing treated superconducting cable was used in the fatigue test. A conventional S-N curve could be obtained through the fatigue test of the 9 strand Cu-Ni/NbTi/Cu composite cables, despite a high possibility of fretting among strands. From the resistivity measurement of a NbTi strand after fatigue tests, it was found that the RRR for annealed cables was 3 times higher than that for as received one, but with increasing the repeated number the RRR decreased which was resulted from the accumulation of damage such as lattice defects and dislocations within the Cu stabilizer.
Critical Current Degradation Behavior in YBCO Coated Conductors Under Torsional Strain
Hyung-Seop Shin,Dizon, J.R.C.,Tae-Hyung Kim,Dong-Woo Ha,Sang-Soo Oh Institute of Electrical and Electronics Engineers 2007 IEEE transactions on applied superconductivity Vol.17 No.2
<P>The I<SUB>c</SUB> degradation behaviors of a YBCO coated conductor (CC) tape (RABiTS/MOD) was investigated using a sample holder which gives torsional angles to HTS tapes. The I<SUB>c</SUB> degradation in YBCO CC tape under torsional strains occurred gradually which is a characteristic feature under torsion. Uniform torsional deformation was induced in the YBCO CC tape evident from the consistent I<SUB>c</SUB> degradation behavior at each subsection along the longitudinal direction of the tape. Similar with the tension case, the reversible behavior of I<SUB>c</SUB> under torsional loading was found. The irreversible strain, epsiv<SUB>irr.t.</SUB>, was ~0.6%. The critical strain defined by the 95% I<SUB>c</SUB> retention criterion was 1.4% which was located within the irreversible limit. The n-value-thetas behavior in the YBCO CC tape was similar to the I<SUB>c</SUB>/I<SUB>c0</SUB>-thetas behavior.</P>
Shin, Hyung-Seop,Dedicatoria, Marlon J.,Gorospe, Alking,Lee, Sang-Heon American Institute of Physics 2015 Review of scientific instruments Vol.86 No.3
<P>The continued development in the design technology of practical superconducting devices adopting high temperature superconductors tapes has led to a deeper understanding of their electromechanical behaviors. Rare-earth-barium-copper-oxide coated conductor (CC) tapes exhibit anisotropy of transport property (I-c) under magnetic field and its intrinsic strain effect is much significant depending on the orientation to the tape surface and the magnetic field intensity applied. Different experimental systems have already been developed to measure the relation of I-c with mechanical strain epsilon, magnetic field intensity B, and its angle of orientation, theta. However, few systems and instruments can measure these relationships simultaneously; either I-c-B-theta or I-c-epsilon-B is usually measured. In this study, a device which can measure these influences simultaneously based on a pair of permanent magnet systems was constructed and the characteristic responses of critical current I-c with strain, magnetic field, and its orientation with respect to the CC tape surface were investigated. The angular dependence of I-c with strain at 77 K in reactive co-evaporation by deposition and reaction GdBCO CC tapes has been measured using the permanent magnet system. The orientation angle of magnetic field with respect to the tape's surface was varied by rotating the rig fixture that holds a pair of permanent magnets. The strain sensitivity of I-c at different angles under low magnetic field was evaluated. As a result, a characteristic surface I-c (epsilon, theta, B) has been constructed as the characteristic response of I-c with strain and varying orientation under magnetic field. (C) 2015 AIP Publishing LLC.</P>
Shin, Hyung-Seop,Diaz, Mark Aangelo,Lee, Jae-Hun The Korea Institute of Applied Superconductivity a 2017 한국초전도저온공학회논문지 Vol.19 No.4
The promising characteristics of 2G high-temperature superconductor (HTS) coated conductor (CC) tapes have made it possible to apply to various electrical device applications. In this study, the mechanical and electromechanical properties of Sn-Cu double layer stabilized GdBCO CC tapes have been characterized. The stress and strain tolerances of $I_c$ in GdBCO CC tapes adopting stainless steel substrate were evaluated using $I_c$-strain measurement at 77 K under both uniaxial tension and monotonic bending conditions. The results were compared to the conventional single Cu layer stabilized CC tape. As a result, the Sn-Cu double layer stabilized GdBCO CC tapes showed somehow lower or comparable electromechanical properties as compared to the Cu stabilized CC tape ones.
Mechanical performance and electrical resistance of ultrasonic welded multiple Cu-Al layers
Shin, Hyung-Seop,de Leon, Michael Elsevier 2017 Journal of materials processing technology Vol.241 No.-
<P>The mechanical performance and electrical resistance of dissimilar and multi-layered Cu-Al sheets, which represent the battery electrodes and tabs, were evaluated by ultrasonic welding (UW). Different possibilities of lap-joining configurations using sheets of Cu and Al were considered. The weld strength at each weld interface of the multi-layered joint was evaluated by 90 degrees peel test and by heat input measured by an infrared imager (IR). The strength of each weld interface of UW joined multiple Cu-Al layers were found to be strong enough to produce a through-thickness tearing. A typical weld criterion for producing a developed nugget was achieved. Weld quality at interfaces was assessed by cross-sectioning the UW joint parts. Depending on the lap joint configuration, weld interfaces were characterized by bonded and unbonded interfaces. Measuring the electrical resistance passing through the joints demonstrated that the unbonded weld interface produced an increase in the joint electrical resistance. The joint electrical resistance measurement is shown to be used as a criterion to validate the quality of Cu-Al battery cell joints. (C) 2016 Published by Elsevier B.V.</P>