Accession Number:

ADA056424

Title:

Analysis of a Nonlinear Electromagnetic Field Penetration Problem,

Descriptive Note:

Corporate Author:

CONSTRUCTION ENGINEERING RESEARCH LAB (ARMY) CHAMPAIGN ILL

Personal Author(s):

• Croisant,William J.
• Nielsen,Paul

Report Date:

1978-06-01

Pagination or Media Count:

14.0

Abstract:

This study examines the time-dependent penetration of a step increase in magnetic field strength H into a semi-infinite conducting medium having a permeability which varies with magnetic field strength. The medium is considered to be isotropic, homogeneous, and initially demagnetized. The medium at any point is presumed to follow its initial magnetization curve for which a simple approximation is assumed. The analytical approach consists of mathematical analysis supplemented with numerical calculations. The problem can be simplified from one involving a second order nonlinear partial differential equation to one involving a second order nonlinear ordinary differential equation utilizing a simple transformation of variables. Although a formal parametric representation of the solution of the second order differential equation is considered, a simple closed form solution in terms of elementary functions does not seem to exist. Hence several analytical techniques, as well as numerical calculations, have been employed to deduce properties of the solution.

Descriptors:

• *ELECTROMAGNETIC FIELDS
• *ELECTRICAL CONDUCTIVITY
• *MATHEMATICAL ANALYSIS
• MAGNETIC FIELDS
• PERMEABILITY
• COMPUTATIONS
• TIME DEPENDENCE
• PENETRATION
• ISOTROPISM
• FERROMAGNETIC MATERIALS
• ELECTROMAGNETIC SHIELDING
• HOMOGENEITY
• DEMAGNETIZATION

Subject Categories:

• Numerical Mathematics
• Electricity and Magnetism

Distribution Statement:

APPROVED FOR PUBLIC RELEASE