The 65 T pulsed magnetic field with 10 ms flat-top has been achieved at the Wuhan National High Magnetic Field Center (WHMFC). This is an upgrade based on the 41 T with 6 ms flat-top system. Both the magnet and the coupling transformer were newly designed and fabricated. The magnet circuit and the auxiliary circuit were driven by ten and two 1 MJ capacitor bank modules, respectively. At the voltage of 19.1 kV for the magnet circuit and 8.5 kV for the auxiliary circuit, peak field of 64 T with 10 ms flat-top and 0.3% flatness was obtained. The primary specific heat measurement of sample CeRhln5 was successfully performed.

Accurate structural analyses of continuous fiber-reinforced polymers (FRPs) are imperative for diverse engineering applications, demanding efficient material constitutive models. Nonetheless, the constitutive modeling of FRPs is complicated by the nonlinear behavior resulting from internal damages and the inherent plasticity. Consequently, this study presents an innovative anisotropic constitutive model for FRPs, designed to adeptly capture both the damage evolution and plasticity. All requisite parameters can be easily obtained through fundamental mechanical tests, rendering the model practical and user-friendly. The model utilizes the three-dimensional Puck criteria to determine damages, initiating the evolution process through a combination of continuum damage mechanics and linear stiffness attenuation methods. This evolution is coupled with a one-parameter plastic model. Subsequently, the numerical implementation method, integrated into ANSYS, is detailed. This emphasizes the Cauchy stress and consistent tangent stiffness solution strategy. Finally, the effectiveness of the developed model is demonstrated through comprehensive verification, encompassing existing biaxial tension and open-hole-tension tests conducted on carbon and glass FRP laminates. The simulation results exhibit a remarkable correspondence with the experimental data, validating the reliability and accuracy of the proposed model.

A triple-coil pulsed magnet aiming at 100 T (Tesla) was designed and tested at the Wuhan National High Magnetic Field Center. The magnet was powered by a 100 MJ pulse generator, a battery bank, and 25 kV capacitor banks in combination. The magnet failed at 83 T, while the whole structure remained intact. The failure process was analyzed by using the recorded waveforms of the voltage and the current, as well as disassembling and dismantling the failed magnet. It shows that the inner coil broke down first, and then the electrical breakdown occurred between the middle and outer coils. The possible reasons were also discussed. The buckling analysis results show that the inner and middle coils would buckle at 71 T and 83 T, respectively, which were consistent with the experimental results. The cross-ply reinforcement method is proposed to enhance the structural stability of high field magnets.

The aim of traditional designs of pulsed magnets is to keep the von-Mises stress on the midplane less than the ultimate tensile strength of materials. However, recently failed high-field experiments showed that some short circuits occurred at the magnet end, which is most possibly caused by the axial displacement of wires. This indicates that the former design is inadequate and accurate axial mechanical analysis of magnets is necessary. In this paper, a finite element model of pulsed magnets considering interface characteristics is proposed. Both the contact status and interfacial friction between the conductor layers and reinforcements can be accounted for Simulations are conducted with a failed 95 T dual-coil prototype, which was originally designed with the self-developed Pulsed Magnet Design Software (PMDS) software. The simulation results show that all the originally expected separations calculated by the PMDS software disappear due to the compression. This makes the calculated maximal von-Mises stress of the inner four reinforcement layers about 600 MPa less than the former designs. The influence of the interfacial friction is also presented. Besides, the simulations show that the maximum axial displacement at the magnet end is up to 8 mm at the designed peak field, which is deadly to the insulations. Hence, we suggest that the axial displacement at the magnet end should also be one design objective of pulsed magnets. At last, the factors affecting the axial displacement are analyzed.