Parameter Estimation for the Jiles-Atherton Model in Weak Fields

The purpose of this article is to estimate the parameters of the Jiles-Atherton hysteresis model, based on minor-loop measurement data in weak applied fields. The well-known hysteresis model by Jiles and Atherton serves as a basis of this article with an extension for the closure of minor loops. In order to represent minor loops correctly, a...

Magnetic Susceptibility Estimation for Magnetostatics

This paper presents a parameter estimation method to determine the linear behavior of an object constructed of thin plates. Based on the magnetostatic field equations, an integral equation is derived that fully determines the induced magnetization, whenever the spatial magnetic susceptibility distribution is known. This forward problem is used...

Testing and numerical simulation of magnetic fields affected by presence of fatigue cracks

Growing applications of high strength steels, which are more sensitive to fatigue, harsher operative environments, and increasing economic value of ship- And offshore structures, such as FPSOs and FLNGs, increase the need for asset integrity management systems. Presently, there are many nondestructive testing methods available. Magnetic methods...

Degaussing System Design Optimization

Steel ships with a magnetic signature requirement are equipped with a degaussing system to reduce their perceptibility for magnetic influence mines. To be able to reduce the magnetic signature accurately, a proper distribution of coils over the ship is essential. Finding the best distribution of coils is a complex optimisation problem, involving...

Interpolation Algorithm for Fast Evaluation of EM Coupling between Wires

Efficient and accurate evaluation of the EM field radiated by a current flowing along a wire is essential to solve the electromagnetic coupling between arbitrary oriented wires. In this paper, a numerically efficient algorithm for the evaluation of coupling is presented. The currents along the wires are expressed in terms of local basis...

Design of Wire Antennas by Using an Evolved Particle Swarm Optimization Algorithm

A Particle Swarm Optimization (PSO) algorithm has been used in conjunction with a full-wave numerical code based on the Method of Moments (MoM) to design and optimize wire antennas. The PSO is a robust stochastic evolutionary numerical technique that is very effective in optimizing multidimensional problems. The goal of the present work is to...

Interpolation Algorithm for Fast Evaluation of EM Coupling between Wires

Development of an electromagnetic signature prediction tool for the Cathodic Protection System;

Representing the ship magnetic field using prolate spheroidal harmonics ┐ a comparative study of methods; 2006BU1-RE

Analysis of the resonant behavior of a complex loaded wire by using the Exact Kernel MoM

This paper describes the implementation of an efficient and accurate numerical methodto compute the current induced along a thin wire surface. We apply the Galerkin Method of Moments to the exact kernel Pocklington's equation. Next, loaded wire antennas are analyzed. Natural frequencies of a wire antenna loaded with different impedance profiles...

Detection of a buried object with pulse-compensated wire antennas

For the detection of a buried object we consider two straight thin-wire antennas above an interface between two homogeneous dielectric half spaces. One antenna is a transmitting wire and the other is a receiving wire. Our aim is to use this simple antenna set up for the detection of buried objects without applying pre and post processing of the...

Detection of a buried wire with two resistively loaded wire antennas

The use of two identical straight thin-wire antennas for the detection of a buried wire is analyzed with the aid of numerical calculations. The buried wire is located below an interface between two homogeneous half-spaces. The detection setup, which is formed by a transmitting and a receiving wire, is located above the interface. The transmitter...

On the feasibility of detecting flaws in artificial heart valves

In this paper, we investigate the feasibility of detecting defects in certain artificial heart valves by determining the electromagnetic behavior of some simple models with the aid of thin-wire integral equations. The idea is to use the stationary current that occurs at late times after the excitation of a closed loop as a discriminator. This...