☆ 4.5 Article

Reversible stress and strain limits of the. critical current of practical REBCO and BSCCO wires

SUPERCONDUCTOR SCIENCE & TECHNOLOGY (2016)

Journal

SUPERCONDUCTOR SCIENCE & TECHNOLOGY

Volume 29, Issue 9, Pages -

Publisher

IOP PUBLISHING LTD

DOI: 10.1088/0953-2048/29/9/094003

Keywords

high T-c superconductor; critical current; stress/strain dependence; reversible stress/strain limit; cyclic loading test

Funding

Ministry of Education, Culture, Sports, Science and Technology, Japan [26420669]
Grants-in-Aid for Scientific Research [26420669] Funding Source: KAKEN

Ask authors/readers for more resources

Protocol

Community support

Reagent

Community support

Abstract

Practical REBCO and BSCCO-2223 tape-shaped wires are now manufactured on an. industrial scale. They are a. typical composite material consisting of superconducting layer/filaments together with functional components. These functional components affect directly the stress and strain dependences of the critical current. When applying an external stress R, the critical current I-c was measured. Then the external stress was reduced to R - 0 and. the recovered critical current I-cr was again. measured. The tensile stress and strain dependences of both normalized critical currents divided by the original value, I-c/I-c0 and I-cr/I-c0 were investigated. In general. I-cr/I-c0 recovered close to unity when the applied stress was low, but its recovering level decreased gradually with increasing applied stress. The definition of. the reversible stress and strain limits was investigated and its validity was proved using. the cyclic loading test. The original definition of reversible stress and strain limits of critical current relates to: (1) when releasing the applied stress and strain, the I-c shall recover to the original value, and (2) when applying the cyclic stresses, the I-c shall keep the original value. Here, as a practical definition for the reversible stress and strain limits, the tensile stress and strain at 99% recovery of I-c have been proposed. On the other hand, it was made clear that the stress and strain at I-c 95% retention are not valid for use commonly as a criterion of reversible stress and strain limits for both practical REBCO and BSCCO-2223 wires.

Authors

I am an author on this paper

Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.5

Not enough ratings

Secondary Ratings

Novelty

Significance

Scientific rigor

Rate this paper

Influence of the initial static stress state on the accumulation behaviour of a coarse-grained soil under long-term cyclic loading

Kai Cui, Dongjie Zhang, Pangju Li, Qionglin Li, Haodong Zhang, Yulan Qing

Summary: A series of cyclic triaxial tests were conducted to investigate the accumulation behavior of coarse-grained soil (CGS) under different initial static stress states. The results show that specimens with higher initial stress ratios or lower confining stresses exhibit greater accumulated axial strain under identical cyclic loading. The plastic shakedown limits were identified, indicating that higher initial stress ratios or lower confining pressures result in lower plastic shakedown limits. Furthermore, the stress states at the plastic shakedown limit for soils with various initial stress states were plotted in the p-q plane and showed a convergence towards a straight line approximately parallel to the strength envelope. A unified plastic shakedown criterion is proposed for soils under different initial stress states, providing a simple method to predict the plastic shakedown limit.

SOIL DYNAMICS AND EARTHQUAKE ENGINEERING (2023)