Issue 32

N. Golinelli et alii, Frattura ed Integrità Strutturale, 32 (2015) 13-23; DOI: 10.3221/IGF-ESIS.32.02 19    mrf mrf steel steel steel B A B A A (12)  Determine the magnetic field induction B steel using its B-H relationship.  Find the required number of amp-turns (NI) by using Kirchhoff’s Law of magnetic circuits:     i i mrf steel NI H L H h H L (13) where h is the fluid gap and L is the single length of each links which compose the circuit. The required number of coil wire resulted N = 160, considering a working current of 1 A. 304 Stainless Steel Air 304 Stainless Steel 430 Stainless Steel Air Rubber Rubber Air 20 AWG [I:153] 1020 Steel 20 AWG [-I:152] 430 Stainless Steel Density Plot: |B|, Tesla 1.276e+000 : >1.343e+000 1.142e+000 : 1.209e+000 1.074e+000 : 1.142e+000 9.401e-001 : 1.007e+000 8.730e-001 : 9.401e-001 8.058e-001 : 8.730e-001 7.387e-001 : 8.058e-001 6.715e-001 : 7.387e-001 6.044e-001 : 6.715e-001 5.372e-001 : 6.044e-001 4.701e-001 : 5.372e-001 4.029e-001 : 4.701e-001 3.358e-001 : 4.029e-001 2.686e-001 : 3.358e-001 2.015e-001 : 2.686e-001 1.343e-001 : 2.015e-001 6.715e-002 : 1.343e-001 <0.000e+000 : 6.715e-002 1.209e+000 : >1.276e+000 1.007e+000 : 1.074e+000 (a) (b) (c) (d) Figure 8 : 2D FEMM Model of the piston head (a) , magnetic field values through the magnetic circuit (b) . Magnification of the central activation area (c) and graph of the magnetic field values B across the activation’s gap along the red line (d) . M AGNETIC FINITE ELEMENT ANALYSIS magnetic finite element analysis was performed after the analytical design of the circuit. This operation is a useful method to compare the calculated values with the simulated ones. Furthermore, these simulations allow one to verify that the magnetic saturation will occur in no section of the magnetic circuit. The software FEMM v4.2 [22] A