Distortion-free single point imaging of multi-layered composite sandwich panel structures.
The results of a magnetic resonance imaging (MRI) investigation concerning the effects of an aluminum honeycomb sandwich panel on the B1 and B0 fields and on subsequent image quality are presented. Although the sandwich panel structure, representative of an aircraft composite material, distorts B0 and attenuates B1, distortion-free imaging is possible using single point (constant time) imaging techniques. A new expression is derived for the error caused by gradient field distortion due to the heterogeneous magnetic susceptibility within a sample and this error is shown not to cause geometric distortion in the image. The origin of the B0 distortion in the sample under investigation was also examined. The graphite-epoxy 'skin' of the panel is the principal source of the B0 distortion. Successful imaging of these structures sets the stage for the development of methods for detecting moisture ingress and degradation within composite sandwich structures.
Marble
Andrew E
AE
MRI Centre, Department of Physics, P.O. Box 4400, University of New Brunswick, Fredericton, New Brunswick, Canada E3B 5A3.
Mastikhin
Igor V
IV
MacGregor
Rod P
RP
Akl
Mohamad
M
LaPlante
Gabriel
G
Colpitts
Bruce G
BG
Lee-Sullivan
Pearl
P
Balcom
Bruce J
BJ