Expandable Magnetostrictive Probe for Tubular Structure Inspection

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Solution Overview

Problem

Existing nondestructive testing methods for tubular structures, such as heat exchanger tubes, face challenges in effectively accessing and inspecting the interior for defects like corrosion using magnetostrictive sensor technology, particularly when the interior access is limited.

Innovation Solution

A probe with expandable MsS sensors and a fluid couplant system is used to mechanically and fluidly couple with the inner tube diameter, allowing for the generation and reception of torsional guided waves, enabling effective defect detection by propagating and reflecting waves along the tube's interior.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If MsS transducers are placed around the outside of the pipeline for testing, then the testing can be performed on pipelines, but the method is impractical for structures requiring interior access

Engineering Contradiction:

Improveadaptability to different tubular structuresVSAvoidease of access to interior

Core Design Contradiction:

Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent inverts the conventional approach by placing the MsS transducer inside the tubular structure rather than outside. The probe is inserted through an open end and the transducer couples to the inner surface, allowing inspection of the tube's interior and wall structure from the inside out, which resolves the accessibility limitation for structures like heat exchanger tubes.

Inventive Principle:

Principle #13The other way round (Inversion)

2Measurement precision

If MsS probe is inserted into the tubular structure for interior testing, then interior defects can be detected, but effective wave coupling to the tube wall is challenging

Engineering Contradiction:

Improvedefect detection precisionVSAvoidwave coupling reliability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent introduces a fluid couplant as an intermediary between the MsS transducer and the tube wall. The couplant fills the gap between the transducer and the inner surface, providing a reliable acoustic and magnetic coupling medium that enables effective wave generation and reception, thereby ensuring both measurement precision and coupling reliability.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The transducer is mounted on a flexible membrane or bladder that can conform to the inner surface of the tube. This flexible interface ensures intimate contact between the couplant and the tube wall across the entire coupling area, maintaining reliable wave coupling even on curved or irregular surfaces.

Inventive Principle:

Principle #30Flexible shells and thin films

3Adaptability or versatility

If the probe is designed to accommodate various tube materials and inner diameters, then versatility is improved, but device complexity increases

Engineering Contradiction:

Improvecompatibility with various tube specificationsVSAvoidprobe structure complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent employs an expandable or adjustable probe structure that can dynamically adapt to different tube inner diameters. The flexible membrane and expandable coupling mechanism allow the probe to conform to various sizes without requiring multiple fixed-size probes, achieving versatility while maintaining relatively simple device architecture.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The probe design incorporates universal features such as the flexible membrane mounting and fluid couplant system that work across different tube materials and dimensions. This multi-functional approach allows a single probe design to serve multiple inspection scenarios, reducing overall system complexity compared to having specialized probes for each tube type.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 solution enables precise location and severity assessment of defects within tubular structures by improving wave coupling and reception, accommodating various tube materials and inner diameters, and facilitating efficient data collection without damaging the structure.

Implementation Method 1

The principle of magnetostriction is based on either shifting or oscillation/rotation between magnetic domains in the material due to applied magnetic fields. Variable magnetic fields are also applied to initiate the rotation of the domains causing the dimensional changes.

Methodology Applied

Scientific EffectMagnetostriction: Magnetostriction

Implementation Method 2

Methodology Applied

Scientific EffectFluid coupling:

Data Source

PatentUS9714922B2Magnetostrictive probe with mechanical and fluid coupling for guided wave testing of tubular structures

Publication Date: 2017.07.25 SOUTHWEST RES INST

AI summary

A probe for use in magnetostrictive testing of tubular structures. The probe has a handle and an outer tube, the latter having an expandable probe head for insertion into the tubular structure. A pair of magnetostrictive sensors is mounted in or on the probe head. A flexible bladder is located inside the outer tube in the area of the probe head, and communicates with a pressurizing cartridge in the probe handle via a bladder tube. The bladder is operable to expand, causing the probe head to expand, which moves the sensors toward the inner wall of the tubular structure. The probe is also equipped with a couplant injector that delivers coupling fluid to any gaps between the inner surface of the tubular structure and the outer surface of the probe.