Flexible Eddy Current Probe for Weld Toe Inspection
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Solution Overview
Problem
Eddy current sensors face challenges in accessing and effectively inspecting the toe area of raised welds due to their complex geometry, which affects signal quality and flaw detection in non-destructive testing of metal objects.
Innovation Solution
A flexible eddy current probe design that combines plus-point coil pairs for close access to the weld toe and an array of pancake coils on a flexible substrate, allowing the probe to conform to curved surfaces and maintain close proximity to the material under test, while using a multiplexer to simplify signal transmission and a replaceable wear surface for durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional eddy current probes are used to inspect the toe area of raised welds, then the probe structure is simple, but the probe cannot access the complex geometry of the weld toe and signal quality deteriorates
Solution Approach 1:
The probe divides the inspection area into different zones using multiple coil arrays (first coil array for weld toe area, second coil array for other areas), allowing each coil array to be optimized for its specific inspection zone and improving overall measurement precision across complex geometries
Solution Approach 2:
The patent introduces a vertical dimension to coil arrangement by positioning coil arrays at different heights above the test object, with the first coil array closer to the weld toe area and the second coil array at a different vertical position, enabling access to complex three-dimensional weld geometries
2Measurement precision
If multiple coil arrays are used to improve flaw detection, then measurement precision improves, but device complexity increases
Solution Approach 1:
The probe uses a single excitation source that can excite multiple different coil arrays (first and second coil arrays) to perform different inspection functions, allowing one device to serve multiple inspection purposes and reducing overall system complexity despite having multiple coil arrays
Solution Approach 2:
The system dynamically switches between different coil arrays based on the inspection area, using the first coil array for weld toe inspection and the second coil array for other areas, allowing the probe structure to adapt its configuration during operation rather than requiring all coils to be active simultaneously
3Measurement precision
If coils are positioned close to the material for good signal quality, then measurement precision improves, but the probe cannot maintain close proximity to complex surfaces
Solution Approach 1:
The patent employs a flexible substrate to mount the coil arrays, allowing the entire probe structure to conform to curved and complex surfaces while maintaining the close proximity between coils and test object needed for high signal quality
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
The flexible probe design enhances signal quality and flaw detection capabilities at the weld toe, balancing cost and performance by using a hybrid approach of plus-point and pancake coils, and improves durability through a separate wear surface, enabling effective inspection of complex weld geometries.
Implementation Method 1
An alternating current is applied to an excitation coil placed in close proximity to the metal object under test. The alternating current in the excitation coil induces an alternating current in the object
Implementation Method 2
The alternating current in the excitation coil induces an alternating current in the object
Data Source
AI summary
A flexible eddy current probe for non-destructive testing of a metallic object may include one or more plus-point coils and a flexible printed circuit having first and second parallel sides, third and fourth parallel sides, and a number of adjacent strips. The strips have first and second ends that are contiguous with the first and second parallel sides, respectively. Each of the strips may contain a pair of coils oriented along the length of the strip, a first coil being proximate to the first end and a second coil being proximate to the second end, and each of the coils is configured to excite an eddy current in the metal object or to sense an eddy current. Each of the strips may also be independently flexible from one another. The eddy current sensor array is configured to be scanned over the metal object.