Magnetostrictive Guided Wave Sensor with Movable Magnet
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing ultrasonic guided wave non-destructive testing methods face inefficiencies and limitations, such as the need for moving cables that are prone to failure and the inability to inspect non-conductive materials like stainless steel, particularly when using electromagnetic acoustic transducers (EMATs).
Innovation Solution
A magnetostrictive sensor with a movable permanent magnet that partially activates a flexible magnetostrictive strip, allowing for efficient generation and detection of guided waves without cables, suitable for various materials and geometries, including stainless steel structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If electromagnetic acoustic transducers (EMATs) are used to generate ultrasonic guided waves, then wave generation is achieved, but the method is limited to highly conducting materials and requires moving cables that are prone to failure
Solution Approach 1:
The patent replaces the electromagnetic actuation system (EMATs requiring cables) with a magnetostrictive system using permanent magnets and AC-coils. This substitution eliminates the need for moving cables while enabling inspection of non-conductive materials like stainless steel, thus resolving both material compatibility and cable reliability issues
Solution Approach 2:
The patent introduces a magnetostrictive strip as an intermediary element that converts electrical energy to mechanical vibrations through magnetostriction. This intermediary mechanism allows wave generation without direct electromagnetic contact with the test material, enabling use on non-conductive materials while eliminating cable requirements
2Area of stationary object
If a single large probe encircling the entire pipe circumference is used, then coverage is achieved, but only distance from the probe can be detected and defect width/position normal to the beam cannot be determined
Solution Approach 1:
The patent divides the single large probe into multiple smaller probes arranged in a line normal to the beam direction. Each probe can be independently positioned and controlled, allowing determination of defect width and position normal to the beam in addition to distance from the probe, thus resolving the measurement precision issue while maintaining coverage
Solution Approach 2:
The patent adds the dimension of probe positioning normal to the beam direction by arranging multiple probes in a line. This dimensional extension enables simultaneous measurement of distance along the beam and position/width normal to the beam, resolving the limitation of single-probe systems
3Measurement precision
If multiple probes are used to inspect from multiple locations, then defect width and position can be determined, but inspection time increases and productivity decreases
Solution Approach 1:
The patent combines multiple probes into a single integrated probe assembly that can be moved as one unit along the scan path. This merging maintains the ability to determine defect width and position through multiple probe positions while reducing the time required for inspection by eliminating the need to individually position and manage separate probes, thus resolving the productivity issue
4Adaptability or versatility
If a magnetostrictive probe with AC coil is moved along the structure, then wave generation is achieved, but cables must be attached to the probe which are subject to periodic failure and may bind on geometric features
Solution Approach 1:
The patent extracts and removes the cable from the probe assembly, replacing it with a cableless magnetostrictive system using permanent magnets and AC-coils. This extraction eliminates cable-related issues such as periodic failure and binding on geometric features, while maintaining the ability to generate waves in various materials, thus resolving both material compatibility and ease of operation issues
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances inspection speed and resolution, reduces manual manipulation, and enables effective detection of defects across large areas with improved signal-to-noise ratio and reduced artifacts, facilitating efficient non-destructive testing of complex structures.
Implementation Method 1
A magnetostrictive sensor with a movable permanent magnet that partially activates a flexible magnetostrictive strip, allowing for efficient generation and detection of guided waves
Data Source
AI summary
A “partial activation” method of magnetostrictive guided wave testing of a structure. A coil-wrapped magnetostrictive strip is acoustically coupled to the surface of the structure. A permanent magnet is placed over a portion of the strip, such that the permanent magnet covers all or most of the width of the strip but only a portion of its length. A pulsed alternating current source activates the magnetostrictive strip, thereby producing magnetostrictive vibrations in the magnetostrictive strip, and thereby resulting in guided waves in the structure. Response signals are received, then the permanent magnet is moved to a next position along the length of the magnetostrictive strip. As the magnet is moved along the strip, the strip is activated and response signals are received, thereby testing a desired portion of the structure under the strip. The response signals are analyzed to determine the presence of anomalies in the structure.