Methods and apparatus for characterizing composite materials for manufacturing quality assurance (QA), periodic inspection during the useful life, or for forensic analysis/material testing. System are provided that relate eddy-current sensor responses to the fiber layup of a composite structure, the presence of impact damage on a composite structure with or without a metal liner, volumetric stress within the composite, fiber tow density, and other NDE inspection requirements. Also provided are systems that determine electromagnetic material properties and material dimensions of composite materials from capacitive sensor inspection measurements. These properties are related to the presence of buried defects in non-conductive composite materials, moisture ingress, aging of the material due to service or environmental/thermal exposure, or changes in manufacturing quality.

A sensing element is provided including a magnetic sensor that detects a first magnetic field component, at least one AC-magnetic field generator that applies at least one additional magnetic field component at a given frequency to the magnetic sensor, where the first magnetic field component and the at least one additional magnetic field component are orthogonal to each other, and at least one demodulator using the given frequency to determine a sensitivity of the sensing element respective to the at least one additional magnetic field component. Also, several methods of operating such sensing element are provided.

A measurement apparatus acquires actually-measured closed magnetic path curve data, actually-measured open magnetic path curve data, and a surface magnetic property value; calculates, for each divided region obtained by sectioning and dividing the permanent magnet, by using a function including a parameter that determines distribution of magnetic property of the permanent magnet, a magnetic property value of the divided region based on an internal magnetic property value extracted from the actually-measured closed magnetic path curve data and the surface magnetic property value; calculates estimated open magnetic path curve data indicating a magnetization curve of the permanent magnet, based on a magnetic property value and the actually-measured closed magnetic path curve data; changes a value of the parameter to minimize a magnetization difference between the actually-measured open magnetic path curve data and the estimated open magnetic path curve data; and outputs a magnetic property value of each of the divided regions.

Multiple magnetic field sensors are arranged around a current-containing volume at multiple longitudinal and circumferential positions. Each sensor measures multiple magnetic field components and is characterized by one or more calibration parameters. A longitudinal primary current flows through two end-to-end electrical conductors that are separated by an arc gap, and flows as at least one longitudinal primary electric arc that spans the arc gap and that moves transversely within the arc gap. Estimated transverse position of the primary electric arc is calculated, based on the longitudinal position of the arc gap, and two or more of the measured magnetic field components along with one or more corresponding sensor positions or calibration parameters. In addition, estimated occurrence, position, and magnitude of a transverse secondary current (i.e., a side arc) can be calculated based on those quantities.

Provided is a space-time fractional conductivity modeling and simulation method of two-phase conducting media, including: 1) setting a simulated computation area, setting electric field or magnetic field distribution nodes in the simulated computation area, and setting an artificial current source at the origin of coordinates; 2) selecting a shape function in the entire computation area by a meshless method, and setting shape function parameters, Gaussian integral parameters, electromagnetic parameters, distance between the transmitting system and the receiving system, and the range of the frozen soil layer; 3) loading a first computation point and searching for nodes in the radius of the support domain, discretizing the definite integral by a 4-point Gaussian integral equation, then interpolating and summing to obtain the fractional derivative of the shape function, assigning the shape function result to the corresponding position of the large sparse matrix in the spatial fractional electric field diffusion equation.

The present invention discloses a method and apparatus for simulating and designing structural parameters of an air-core coil. The method for simulating and designing structural parameters of the air-core coil includes: building an impedance function of the air-core coil according to a structural parameter variable, the air-core coil being of a differential structure and being wound in a completely parallel winding fashion; building an index function of the air-core coil by calculating an equivalent bandwidth, sensitivity and an equivalent noise power spectrum by means of the impedance function. The method is intuitive, and makes calculation of the optimized technological and structural parameters easier and more convenient, thus reducing the amount of calculation and shortening the calculation time.

The present invention describes method directed to magnetic resonance (MR) imaging simulation, said method comprising—partitioning a pulse sequence in parts that have RF excitation and parts that do not have RF excitation;—for each of the parts that do not have the RF active, called gradient parts, performing compression of the gradient parts and then representing signals driving the gradients as an accumulation of area until a readout time point; and then performing the simulation.

A measurement apparatus acquires actually-measured closed magnetic path curve data, actually-measured open magnetic path curve data, and a surface magnetic property value; calculates, for each divided region obtained by sectioning and dividing the permanent magnet, by using a function including a parameter that determines distribution of magnetic property of the permanent magnet, a magnetic property value of the divided region based on an internal magnetic property value extracted from the actually-measured closed magnetic path curve data and the surface magnetic property value; calculates estimated open magnetic path curve data indicating a magnetization curve of the permanent magnet, based on a magnetic property value and the actually-measured closed magnetic path curve data; changes a value of the parameter to minimize a magnetization difference between the actually-measured open magnetic path curve data and the estimated open magnetic path curve data; and outputs a magnetic property value of each of the divided regions.

Improved magnetic component models, circuit simulation systems and methods are presented for simulating operation of a modeled magnetic circuit component in which user input defines magnetically susceptible core geometry of the modeled magnetic circuit component, a core model simulates operation of the magnetically susceptible core at least partially according to the geometry of the magnetically susceptible core, and one or more coil models simulate operation of coils wound around the magnetically susceptible core to provide a scalable model with geometry adjustable permeability for fluxgate magnetic sensors, transformers, inductors or other modeled components.

Multiple magnetic field sensors are arranged around a current-containing volume at multiple longitudinal and circumferential positions. Each sensor measures multiple magnetic field components and is characterized by one or more calibration parameters. A longitudinal primary current flows through two end-to-end electrical conductors that are separated by an arc gap, and flows as at least one longitudinal primary electric arc that spans the arc gap and that moves transversely within the arc gap. Estimated transverse position of the primary electric arc is calculated, based on the longitudinal position of the arc gap, and two or more of the measured magnetic field components along with one or more corresponding sensor positions or calibration parameters. In addition, estimated occurrence, position, and magnitude of a transverse secondary current (i.e., a side arc) can be calculated based on those quantities.