Magnetoelastic buckling: Why theory and experiment disagree

Document Type


Publication Date



College of Forest Resources and Environmental Science; Department of Mechanical Engineering-Engineering Mechanics


This paper does not stand alone; it is directly related to N.S. Christopherson's experimental study1,2 of the magnetoelastic bending of thin steel plates, presented at a recent SEM meeting. It is, in fact, an extension of that study and relies upon some of Christopherson's data. In 1968, Moon and Pao presented a theory of the magnetoelastic buckling of a beam plate in a uniform magnetic field which differed from experimental results by a factor of two. Attempts to explain the discrepancy still leave approximately 25-percent error in the theoretical results as compared with experiment. We show that the assumption made by Moon and Pao-that a plate element experiences a force system consisting only of a couple, whose magnitude is proportional to the rotation of the element-is invalid for finite plates. An experiment is suggested for determining whether the assumption is valid for infinite plates. The present state of knowledge concerning magnetoelastic buckling is briefly summarized. Several types of magnetoelastic buckling are identified and briefly contrasted. Attention is directed to the importance of field discontinuities in problems involving magnetic deformation. Two paradoxical aspects of the Moon-Pao formula for the magnetoelastic buckling of beam plates are pointed out and briefly discussed.

Publisher's Statement

© 1988 Society for Experimental Mechanics, Inc. Publisher’s version of record:

Publication Title

Experimental Mechanics