Hybrid wound/etched winding constructs for scanning and monitoring

Abstract

Combined wound and micro-fabricated winding constructs are described for the inspection of materials and the detection and characterization of hidden features or flaws. These constructs can be configured as sensors or sensor arrays that are surface mounted or scanned over conducting and / or magnetizable test materials. The well-defined geometry obtained micro-fabricated windings and from carefully wound coils with known winding positions permits the use of model based inversions of sensed responses into material properties. In a preferred embodiment, the primary winding is a wound coil and the sense elements are etched or printed. The drive or sense windings can also be mounted under fasteners to improve sensitivity to hidden flaws. Ferrites and other means may be used to guide the magnetic flux and enhance the magnetic field in the test material.

Description

RELATED APPLICATION(S) [0001] This application claims the benefit of U.S. Provisional Application No. 60 / 473,180 filed May 23, 2003 the entire teachings of which are incorporated herein by reference.BACKGROUND OF THE INVENTION [0002] This application relates to nondestructive materials characterization, particularly quantitative, model-based characterization of surface, near-surface, and bulk material condition for flat and curved parts or components using magnetic field based or eddy-current sensors. Characterization of bulk material condition typically includes (1) measurement of changes in material state, i.e., degradation / damage caused by fatigue damage, creep damage, thermal exposure, or plastic deformation; (2) assessment of residual stresses and applied loads; and (3) assessment of processing-related conditions, for example from aggressive grinding, shot peening, roll burnishing, thermal-spray coating, welding or heat treatment. It also includes measurements characterizing a ...

AI Technical Summary

Benefits of technology

"The patent describes a new method for measuring the properties of conducting materials using special sensors. These sensors have a unique design that allows for accurate modeling of the magnetic field and enhances the ability to observe changes in the material. The sensors can be attached to the same substrate as the material being tested, making it easier to measure changes in the material. The method can be used in various applications such as detecting flaws in fasteners or analyzing the properties of magnetic materials. The patent also describes methods to improve the penetration of the magnetic field into the material being tested, such as using low conductivity materials or magnetizable materials. Overall, the patent provides a new and effective way to measure the properties of conducting materials."

Problems solved by technology

However, use of a single sensor has disadvantages in that the scanning can take an excessively long time and care must be taken when registering the measured values together to form a map or image of the properties.

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