Acoustic Emission Yield Detection in Mechanical Structures
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Detecting yield in mechanical structures, particularly in performance or safety-critical systems like aircraft, is complex due to the small and difficult-to-measure deformations that occur beyond the elastic limit, requiring immediate assessment for repair or replacement.
Innovation Solution
A method utilizing acoustic emission data to detect yield by selecting parameters such as pulse rise time or amplitude, determining reference ranges from yield tests, and comparing operational data to these ranges to signal yield detection, with the option to require multiple parameters within specified ranges for confirmation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional deformation measurement methods are used to detect yield, then the measurement may capture visible deformations, but the method fails to detect small deformations that occur in performance-critical structures
Solution Approach 1:
The patent replaces traditional mechanical deformation measurement systems with an acoustic emission detection system. Acoustic sensors detect high-frequency stress waves generated during yield events, converting mechanical phenomena into acoustic signals for analysis. This substitution enables detection of yield at the acoustic level, capturing events that produce acoustic signatures even when macroscopic deformations remain below visual detection thresholds.
Solution Approach 2:
The patent changes the detection parameter from macroscopic deformation (length, shape) to acoustic emission parameters (frequency, amplitude, rise time, duration). By monitoring acoustic parameters such as pulse rise time (10-100 microseconds), amplitude (dB), and duration (microseconds to milliseconds), the system detects yield events through acoustic signatures rather than physical deformation, enabling detection of events that do not produce visible structural changes.
2Reliability
If acoustic emission parameters are monitored to detect yield, then detection sensitivity is improved, but the complexity of data analysis and parameter selection increases
Solution Approach 1:
The patent transforms complex acoustic emission waveforms into a simplified set of characteristic parameters including rise time (10-100 microseconds), amplitude (dB), duration (microseconds to milliseconds), and frequency content. By reducing the acoustic signal to these key parameters, the system maintains high detection sensitivity while enabling practical analysis through parameter comparison against reference values or thresholds.
Solution Approach 2:
The patent applies different parameter importance weights to different acoustic emission parameters based on the specific application and material type. Not all parameters are equally important for every yield detection scenario; the system can emphasize parameters such as rise time for certain materials while de-emphasizing others, allowing tailored analysis that reduces complexity while maintaining reliability for specific use cases.
3Reliability
If multiple acoustic parameters are required to be within reference ranges for yield confirmation, then false positive detection is reduced, but the response time for yield detection increases
Solution Approach 1:
The patent implements a configurable threshold for the number of parameters that must match reference ranges to confirm yield. Rather than requiring all parameters to match (which would maximize accuracy but slow response), the system can be configured to require only a subset of parameters (e.g., 2 out of 3, or 3 out of 4) to be within reference ranges. This partial matching approach provides a balanced response time while maintaining sufficient detection reliability.
Solution Approach 2:
The patent allows the parameter matching requirement to be dynamically adjusted based on operational context, material type, and risk tolerance. For critical safety applications, the system can require more parameters to match before confirming yield. For less critical applications or when rapid response is prioritized, the system can reduce the matching requirement. This dynamic configuration enables optimization of the accuracy-response time tradeoff for different operational scenarios.
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 accurate and timely detection of yield in mechanical structures, allowing for proper assessment and potential replacement of affected components, even when deformations are small and difficult to measure.
Implementation Method 1
yield occurs in a structure when the structure is stressed beyond its elastic limit... detecting yield in a mechanical structure by means of acoustic emission data from the structure... detecting acoustic emissions emitted from the reference structure during the yield test
Data Source
AI summary
A method, apparatus and software is disclosed for using parameters of acoustic emissions emitted from an structure, such as aircraft landing gear, for detecting yield in the structure.