@article{le_chan_schwartz_2014, title={A two-dimensional ordinary, state-based peridynamic model for linearly elastic solids}, volume={98}, ISSN={["1097-0207"]}, DOI={10.1002/nme.4642}, abstractNote={SUMMARY}, number={8}, journal={INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING}, author={Le, Q. V. and Chan, W. K. and Schwartz, J.}, year={2014}, month={May}, pages={547–561} }
 @article{le_chan_schwartz_2014, title={Two-dimensional peridynamic simulation of the effect of defects on the mechanical behavior of Bi2Sr2CaCu2Ox round wires}, volume={27}, ISSN={["1361-6668"]}, DOI={10.1088/0953-2048/27/11/115007}, abstractNote={Ag/AgX sheathed Bi2Sr2CaCu2Ox (Bi2212) is the only superconducting round wire (RW) with high critical current density (Jc) at high magnetic (>25 T) and is thus a strong candidate for high field magnets for nuclear magnetic resonance and high energy physics. A significant remaining challenge, however, is the relatively poor electromechanical behavior of Bi2212 RW, yet there is little understanding of the relationships between the internal Bi2212 microstructure and the mechanical behavior. This is in part due to the complex microstructures within the Bi2212 filaments and the uncertain role of interfilamentary bridges. Here, two-dimensional peridynamic simulations are used to study the stress distribution of the Bi2212 RWs under an axial tensile load. The simulations use scanning electron micrographs obtained from high Jc wires as a starting point to study the impact of various defects on the distribution of stress concentration within the Bi2212 microstructure and Ag. The flexibility of the peridynamic approach allows various defects, including those captured from SEM micrographs and artificially created defects, to be inserted into the microstructure for systematic study. Furthermore, this approach allows the mechanical properties of the defects to be varied, so the effects of porosity and both soft and hard secondary phases are evaluated. The results show significant stress concentration around defects, interfilamentary bridges and the rough Bi2212/Ag interface. In general, the stress concentration resulting from porosity is greater than that of solid-phase inclusions. A clear role of the defect geometry is observed. Results indicate that crack growth is likely to initiate at the Ag/Bi2212 interface or at voids, but that voids may also arrest crack growth in certain circumstances. These results are consistent with experimental studies of Bi2212 electromechanical behavior and magneto-optical imaging of crack growth.}, number={11}, journal={SUPERCONDUCTOR SCIENCE & TECHNOLOGY}, author={Le, Q. V. and Chan, W. K. and Schwartz, J.}, year={2014}, month={Nov} }
 @article{liu_le_schwartz_2012, title={Influencing factors on the electrical transport properties of split-melt processed Bi2Sr2CaCu2Ox round wires}, volume={25}, number={7}, journal={Superconductor Science & Technology}, author={Liu, X. T. and Le, Q. V. and Schwartz, J.}, year={2012} }
 @article{mbaruku_le_song_schwartz_2010, title={Weibull analysis of the electromechanical behavior of AgMg sheathed Bi2Sr2CaCu2O8+x round wires and YBa2Cu3O7-delta coated conductors}, volume={23}, ISSN={["0953-2048"]}, DOI={10.1088/0953-2048/23/11/115014}, abstractNote={The development of superconducting magnets requires not only a conductor that is capable of carrying sufficient critical current density (Jc) at high magnetic field, but also one that is mechanically robust and predictable. Here, the electromechanical behavior of AgMg sheathed Bi2Sr2CaCu2O8 + x (Bi2212) round wires and YBa2Cu3O7 − δ (YBCO) coated conductors is studied using a statistical approach based upon three-parameter Weibull statistics, where the three parameters α, β, and γ describe the scale, shape and location of the resulting distribution function. The results show that Bi2212 round wire has significantly different behavior than previously studied Bi2212 tape conductors, with evidence of an underlying mechanically strong but poorly connected electrical ‘backbone’ in the round wire that is not found in the tape conductor. Furthermore, the Bi2212 round wire results indicate a distribution in the dependence of critical current upon strain (Ic(ε)) at the microscopic level, consistent with reports that a complex network of interfilamentary bridges plays a key role in connectivity. Unlike the behavior of either Bi2212 round wire or tape, the YBCO coated conductor shows a universal behavior for strains below yield, consistent with the presence of a strong, stiff NiW substrate that dominates the mechanical behavior, and a high purity, high density, highly textured YBCO layer with reversible electromechanical properties. These results indicate that, in particular for Bi2212 conductors, the strain-dependence of the location parameter, γ(ε), which defines the minimum critical current for any segment of conductor at a particular value of strain, is a more important function for magnet design than Ic(ε) or the critical strain, εc. Using the approach reported previously and applied here, this curve is readily obtained using a limited length of conductor, but provides an important level of conservatism to the design of magnets using long lengths of conductor.}, number={11}, journal={SUPERCONDUCTOR SCIENCE & TECHNOLOGY}, author={Mbaruku, A. L. and Le, Q. V. and Song, H. and Schwartz, J.}, year={2010}, month={Nov} }