Analysis of mesoscopic stress states with delamination and their relation to critical current under bending deformation in Bi2223/Ag superconducting composite tapes
Analysis of mesoscopic stress states with delamination and their relation to critical current under bending deformation in Bi2223/Ag superconducting composite tapes
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DOI：
10.1088/0953-2048/18/12/022
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发表时间：
2005-12
影响因子：
3.6
通讯作者：
M. Hojo;M. Nakamura;Mototsugu Tanaka;T. Adachi;M. Sugano;Shojiro Ochiai;K. Osamura
中科院分区：
文献类型：
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作者：
M. Hojo;M. Nakamura;Mototsugu Tanaka;T. Adachi;M. Sugano;Shojiro Ochiai;K. Osamura
对Bi 2223/Ag/Ag合金超导复合带材在弯曲变形下的介观应力和应变状态进行了理论分析和实验研究。本研究中使用的磁带作为VAMAS循环程序的标准样品（分类为VAM 1和VAM 3）。基于无损伤初始状态完成了详细的带弯曲分析，并且将由于Bi 2223细丝断裂而导致的临界电流Ic的计算降低与实验Ic降低进行了比较。计算出的Ic远低于实验中获得的两种磁带。金相分析表明，在收到的以及弯曲测试磁带分层的存在。因此，对分析进行了修改，以包括分层，并在分层占据胶带中平面的整个宽度的情况下完成分析。计算出的IC与分层是高于两个磁带的实验结果。脱层占据中平面的部分宽度解释了这种差异。最后，通过与实验结果和理论分析结果的比较，计算出了脱层处的宽度比。该比率随着胶带曲率的增加而增加。
The mesoscopic stress and strain states of Bi2223/Ag/Ag-alloy superconducting composite tapes have been studied both analytically and experimentally under bending deformation. The tapes used in the present study were supplied as the standard samples for the VAMAS round-robin program (classified as VAM1 and VAM3). Detailed tape bending analysis was completed based on a damage-free initial state, and the calculated decrease of critical current, Ic, due to Bi2223 filament fracture was compared to the experimental Ic decrease. The calculated Ic was much lower than that obtained in the experiments for both tapes. Metallography indicated the presence of delamination in as-received as well as bend-tested tapes. The analysis was therefore modified to include delamination and it was completed for the case where delamination occupied the full width of the tape mid-plane. The calculated Ic with delamination was higher than the experimental results for both tapes. Delamination occupying partial width of the mid-plane explained this difference. Finally, the width ratio where delamination exists was calculated by comparing the analytical results with delamination and experimental results. This ratio increased with increasing curvature of the tape.