Surface Acoustical Wave Resonance Inspection for Defect Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current nondestructive testing methods for surface defects in parts are limited in their ability to accurately identify and characterize surface defects without causing damage, particularly in distinguishing between surface and subsurface discontinuities.
Innovation Solution
The method involves exciting a part-under-test with input frequencies to identify surface acoustical wave (SAW) modes and reference peaks, assessing degeneracy assessment zones for degenerate peak conditions, and determining a surface defect trigger condition based on spacing thresholds between these peaks, allowing for the characterization of surface defects without destructive testing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional nondestructive testing methods are used to detect surface defects, then detection capability is provided, but accuracy in distinguishing surface defects from subsurface discontinuities deteriorates
Solution Approach 1:
The method segments the frequency response into distinct zones: a first zone between a surface acoustic wave mode and a reference peak where surface defects produce degenerate peaks, and a second zone where subsurface defects produce non-degenerate peaks. This segmentation enables accurate discrimination between surface and subsurface defect types.
Solution Approach 2:
The method uses mechanical vibration at multiple frequencies to excite surface acoustic wave modes in the part. By analyzing the vibrational frequency response and identifying degenerate peaks within specific zones, the method detects surface defects with high accuracy while distinguishing them from subsurface discontinuities.
2Measurement precision
If ultrasonic testing is used to detect both surface and subsurface defects, then detection depth is improved, but ability to specifically identify surface defects deteriorates
Solution Approach 1:
The method applies local quality by focusing analysis on a specific first zone in the frequency response that is characteristic of surface defects. By examining only this localized region for degenerate peaks, the method maintains high surface defect specificity while the broader ultrasonic technique provides deep penetration capability.
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
This approach enables accurate and nondestructive identification of surface defects by analyzing frequency responses, improving the detection of surface defects and reducing the risk of misclassifying subsurface issues as surface defects.
Implementation Method 1
A first surface acoustical wave (SAW) mode is identified in a frequency response of the part-under-test to this excitation
Implementation Method 2
A first surface acoustical wave (SAW) mode is identified in a frequency response of the part-under-test to this excitation. A first reference peak is also identified in this same frequency response.
Data Source
AI summary
A system and method for evaluating a part-under-test (120) is disclosed. The part-under-test (120) is excited using at least one drive frequency. A first surface acoustical wave (SAW) mode (206) is identified in the frequency response (200). A separate reference peak (204) for the identified SAW mode (206) is also identified in the frequency response (200). At least one degeneracy assessment zone (208) is evaluated for existence of a surface defect trigger condition. If a surface defect trigger condition exists, the part-under-test (120) may be rejected. Otherwise, the part-under-test (120) may be accepted.