Boss Cracking Detection Using Diametric Piezoelectric Sensors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for detecting damage in the bosses of composite cylinders, particularly blind bosses, are inadequate due to the inaccessible nature of the fractured surface, making it challenging to assess cracking using traditional non-destructive testing methods.
Innovation Solution
A system comprising broadband piezoelectric sensors strategically positioned on the outer surface of the boss's neck, which detect deformation data and utilize modal acoustic emission analysis to determine if a boss cracking event has occurred, including phase shift, arrival time differences, and frequency content analysis to identify crack extension or closure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional non-destructive testing methods are used to detect damage in blind bosses, then the inspection process is simple, but the detection capability is insufficient due to inaccessible fractured surfaces
Solution Approach 1:
The patent replaces traditional mechanical non-destructive testing methods with an acoustic emission-based sensing system. Sensors detect deformation data and acoustic signals from crack events, eliminating the need for physical access to fractured surfaces while significantly improving detection capability.
Solution Approach 2:
The patent introduces sensors as intermediary devices that indirectly detect crack events through deformation data and acoustic emissions. This intermediary approach allows detection of internal crack events in blind bosses without direct access to the fractured surfaces, resolving the accessibility problem.
2Measurement precision
If sensors are placed on the boss neck to detect deformation data, then crack detection accuracy improves, but the device complexity increases
Solution Approach 1:
The patent places sensors at specific locations on the boss neck where deformation data and acoustic emissions from crack events are most prominent. This localized sensor placement optimizes detection accuracy while minimizing the number of sensors required, balancing precision and complexity.
Solution Approach 2:
The patent pre-positions sensors on the boss neck before crack events occur, ensuring they are in optimal locations to detect deformation data and acoustic emissions. This preliminary placement simplifies the detection process and reduces the need for complex real-time sensor positioning.
3Reliability
If modal acoustic emission analysis is used to analyze deformation data, then detection reliability improves, but processing time increases
Solution Approach 1:
The patent uses periodic analysis of deformation data through modal acoustic emission techniques, analyzing signals at specific intervals and frequency ranges. This periodic approach identifies characteristic crack event patterns reliably while maintaining efficient processing speeds by focusing on relevant time windows.
Solution Approach 2:
The patent applies partial analysis by focusing on specific frequency ranges and signal characteristics associated with crack events, rather than analyzing all possible signal parameters. This selective analysis maintains high detection reliability while reducing overall processing time.
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 system effectively detects fatigue crack growth and damage in composite overwrapped pressure vessel bosses, preventing the reuse of compromised cylinders by providing accurate and timely notifications of potential damage.
Implementation Method 1
The first sensor and the second sensor may be broadband piezoelectric sensors
Implementation Method 2
The controller may determine whether the boss cracking event has occurred using modal acoustic emission (MAE) to analyze the first deformation data and the second deformation data
Data Source
AI summary
Disclosed is a system for monitoring a boss of a composite structure for a boss cracking event. The system includes a first sensor located on an outer surface of a neck of the boss and configured to detect first deformation data associated with the boss. The system also includes a second sensor located on the outer surface of the neck of the boss at a location diametrically opposite of the first sensor and configured to detect second deformation data associated with the boss. The system also includes a controller communicatively coupled to the first sensor and the second sensor and configured to determine, based on the first deformation data and the second deformation data, whether a boss cracking event has occurred.