Abstract
This paper describes the estimation of sound power radiating from Open type MRI. Gradient coil to generate gradient magnetic field, which was a composite of copper wire and GFRP, was modeled as a material where mechanical properties were distributed. Young's modulus and Poison's ratio of a finite element of the disk was calculated by applying Halpin-Tsai's equation. FEM modal analysis of the disk was carried out and the vibration response against the distributed excitation due to Lorentz force was calculated. The sound radiation power estimated with the vibration response agreed well with the measured one. The suitable arrangement of fixing bolts to reduce sound power was searched with the estimation. It was confirmed that the maximum value of the sound radiation power could be reduced by 0.5dB.
