PSI - Issue 50

V.V. Titkov et al. / Procedia Structural Integrity 50 (2023) 284–293 Titkov V.V. et al. / Structural Integrity Procedia 00 (2019) 000 – 000

292

9

t  



( )

B t

B e

t



0 sin

2 2   

  

  

.

(15)

1 1



arc ( tg

)







2 2 

2





Particularly for small attenuations δ<ω/4π B max ≈ B 0 parameter β exceeds 10. At the same time, the induction amplitude sufficient for the occurrence of a low-cycle fatigue mode will be B max = 17 T and the system of inequalities (13) is fulfilled. Evaluation of the solenoid lifespan in case of destruction by the mechanism of low-cycle fatigue (Karpova I.M. & Titkov V.V., 1995; Tikhomirov & Alekseev, 2017): 2 1 2 2 f N f p             . (16) For steel: ε f equals 0.7 (Karpova I.M. & Titkov V.V., 1995; Lau, 1991; Manson, 1966). With a sharp surface effect Δ << R 1 , the range of plastic deformation Δε p can be estimated by the formula (Karpova I.M. & Titkov V.V., 1995): The resource estimate according to the formula (16) for the heating temperature of the inner surface of the solenoid with a pulse current of 200 – 300 0 C gives N f = 900 – 2500 pulses, which is significantly lower than the resource estimate given above at the amplitude of a unipolar induction pulse with an amplitude of 30 T. 5. Conclusion When generating unipolar pulses of a strong magnetic field with an amplitude of 20 – 40 T in solenoids, the device's resource is limited by the action of two factors: mechanical and thermal. At the same time, the lifespan of the solenoid, limited by progressive residual deformation, with unipolar induction pulses with a duration of 100 microseconds, is realized at amplitudes over 30 T. At lower amplitude values, the main factor limiting the resource is the low-cycle fatigue of the metal within the skin layer of the conductive material. References Artamonov B.A. et al. (1983). Electrophysical and electrochemical methods of materials processing. Processing of materials using concentrated energy sources. (Vol. 208). Vysshaya shkola. Hall, P. M. (1991). Creep and Stress Relaxation in Solder Joints. In Solder Joint Reliability (pp. 306 – 332). Springer US. https://doi.org/10.1007/978-1-4615-3910-0_10 Hans J Schneider-Muntau (Ed.). (1998). Megagauss Magnetic Field Generation, Its Application to Science and Ultra-High Pulsed-Power Technology. In Megagauss Magnetic Field Generation, Its Application to Science and Ultra-High Pulsed-Power Technology. WORLD SCIENTIFIC. Heinz E. Knopfel. (2000). Magnetic fields: A comprehensive theoretical treatise for practical use (Vol. 890). John Willey & Sons. I.S.Grigoriev, & E.Z.Meilikhov (Eds.). (1991). Physical quantities. Handbook [in Russian] (Vol. 1236). Energoatomizdat. Karpova I.M., & Titkov V.V. (1994). Analysis of the deformation stability of conductive materials in a strong pulsed magnetic field. Technical Physics, 64(7), 137 – 147. Karpova I.M., & Titkov V.V. (1995). Thermoelastic deformation of the skin layer and resource estimation of thick-walled solenoids in a strong pulsed magnetic field. Technical Physics, 65(6), 54 – 63. Komel’kov V. S. (Ed.). (1970). High Current and Magnetic -Field Pulse Techniques [in Russian] (Vol. 338). Atomizdat. 2 0 (1 ) S s   3     T   p E . (17)