Seamless Pipe Eccentricity Characterization Using Fourier Wall Analysis
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Solution Overview
Problem
Seamless pipe manufacturing processes induce wall thickness variations and eccentricities that are difficult to correct, affecting the pipe's quality and leading to potential product rejection, necessitating a method to distinguish and address different eccentricity modes during the manufacturing process.
Innovation Solution
A method using an ultrasound-based measurement tool to measure the wall thickness profile of seamless pipes, applying Fourier transforms to identify amplitude peaks associated with rotational and linear eccentricity modes, filtering these peaks, and modeling the filtered profiles to represent the eccentricity modes, allowing for corrective measures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional measurement methods are used to detect wall thickness variations, then the measurement process is simple, but the measurement precision is insufficient to distinguish different eccentricity modes
Solution Approach 1:
The patent segments the continuous wall thickness profile into discrete measurement points around the pipe circumference. By dividing the measurement into multiple angular positions and applying Fourier transform, the system can identify specific frequency components corresponding to different eccentricity modes (e.g., 1st order, 2nd order), thereby achieving precise characterization of eccentricity patterns while using a relatively simple ultrasonic measurement probe.
Solution Approach 2:
The patent introduces Fourier transform as an intermediary mathematical tool that bridges the gap between raw wall thickness measurements and eccentricity mode identification. This intermediary processing step converts the complex wall thickness profile data into frequency domain representation, where different eccentricity modes appear as distinct amplitude peaks at specific frequencies, enabling precise differentiation without requiring complex physical measurement devices.
2Measurement precision
If comprehensive wall thickness measurements are performed along the entire pipe length, then the detection accuracy improves, but the measurement time increases
Solution Approach 1:
The patent extracts only the essential information needed for eccentricity mode identification by applying Fourier transform to the wall thickness profile. Instead of analyzing the entire continuous profile in detail, the method extracts the dominant frequency components that correspond to specific eccentricity modes. This extraction approach maintains high detection accuracy while significantly reducing the computational and temporal resources required compared to comprehensive analysis of all measurement points.
Solution Approach 2:
The patent performs measurements at multiple angular positions around the pipe circumference (excessive action in terms of measurement points), but then uses Fourier analysis to identify only the critical frequency components that represent eccentricity modes. This partial focus on specific frequency components rather than all measurement data enables accurate eccentricity characterization without requiring excessive measurement time for complete profile analysis.
3Measurement precision
If multiple measurement points are taken around the pipe radius to identify eccentricity patterns, then the measurement precision improves, but the device complexity increases
Solution Approach 1:
The patent employs a single ultrasonic measurement probe that can measure wall thickness at multiple angular positions around the pipe circumference. This universal probe design performs the function of multiple measurement devices by rotating or moving to different positions, thereby achieving comprehensive wall thickness profiling and eccentricity mode identification without requiring multiple complex measurement tools simultaneously.
Solution Approach 2:
The patent creates a digital copy or model of the pipe's wall thickness profile through ultrasonic measurements at multiple points. By constructing this virtual representation and applying Fourier transform, the system can analyze eccentricity modes without physically disassembling or modifying the pipe. This digital modeling approach maintains measurement precision while avoiding the complexity of multiple physical measurement devices or invasive measurement techniques.
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
Enables precise characterization and correction of eccentricity modes, minimizing product rejection by identifying and addressing rotational and linear eccentricities induced during the manufacturing process, thereby improving the quality of seamless pipes.
Implementation Method 1
measuring a wall thickness profile along a length and around a radius of the seamless pipe using an ultrasound-based measurement tool
Implementation Method 2
applying a Fourier transform to the wall thickness profile to obtain a frequency spectrum
Implementation Method 3
The ultrasound-based measurement tool comprises a hollow passageway and one or more laser ultrasonic-based measuring probe projecting therein
Data Source
AI summary
A method of characterizing at least one rotational and at least one linear eccentricity modes of a wall thickness of a seamless pipe induced during a manufacturing process of the seamless pipe. The method comprises the steps of measuring a wall thickness profile along and around a length of the seamless pipe using a ultrasound-based measurement tool; applying a Fourier transform to the wall thickness profile to obtain a frequency spectrum; identifying one or more amplitude peaks in the frequency spectrum; associating each amplitude peak to a corresponding one of the at least one rotational eccentricity modes; filtering the one or more amplitude peaks out of the frequency spectrum; applying an inverse Fourier transform to the frequency spectrum to obtain a filtered wall thickness profile; and modeling the filtered wall thickness profile into a radial profile of the seamless pipe representative of the at least one linear eccentricity modes.