Vibration Wave Defect Analysis Beneath Opaque Surfaces
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing non-destructive testing methods using laser light and optical interferometry are ineffective in detecting defects beneath opaque materials on an object's surface.
Innovation Solution
Induce a travelling wave on the object's surface using an exciter, such as a piezoelectric transducer, and measure vibration data on a spatially separated surface to detect defects through changes in wave properties, even when the analysis surface is covered by opaque material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If optical interferometry is used to detect defects on the surface, then measurement precision is improved, but defects beneath opaque materials cannot be detected
Solution Approach 1:
The patent applies mechanical vibration by exciting the object at its natural frequencies to induce standing waves on the surface. This vibration causes the surface to oscillate, and defects beneath opaque materials alter the vibration patterns. By measuring these vibration changes with optical interferometry, defects that would otherwise be invisible under opaque coatings can be detected, thus expanding detection coverage while maintaining measurement precision.
2Adaptability or versatility
If the measurement surface is spatially separated from the excitation surface, then defects beneath opaque materials can be detected, but the complexity of the system increases
Solution Approach 1:
The patent employs optical interferometry as a universal measurement technique that can detect surface vibrations regardless of their location on the object. The same optical system can measure vibrations on the excitation surface, measurement surface, or any intermediate surface. This multi-functionality allows defect detection beneath opaque materials without requiring separate specialized equipment for each surface, thereby managing system complexity while expanding detection capabilities.
Solution Approach 2:
The patent uses the object's surface vibrations as an intermediary to transmit information about subsurface defects. Instead of directly probing beneath opaque materials, the vibration waves travel through the material and carry information about defects to the measurement surface. This intermediary approach allows indirect detection of hidden defects using non-contact optical methods, avoiding the need for complex direct subsurface probing equipment.
3Measurement precision
If vibration frequency excitation is applied, then defects can be detected through wave property changes, but energy consumption increases
Solution Approach 1:
The patent uses periodic vibration excitation at the object's natural frequencies to induce standing waves. This periodic action resonates with the object's inherent vibrational modes, requiring minimal energy input to maintain sustained vibrations. The resonant excitation amplifies the vibration signals, making defect-induced changes more detectable while keeping energy consumption low compared to non-resonant continuous excitation.
Solution Approach 2:
The patent exploits phase changes in the vibration waves as they interact with subsurface defects. When vibration waves encounter defects beneath opaque materials, they undergo phase shifts and amplitude changes. By detecting these phase transitions in the vibration patterns, the system can identify defects with high precision using minimal excitation energy, as the phase information provides strong defect contrast without requiring intense vibration amplitudes.
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 detection of defects beneath opaque materials by analyzing changes in wave properties, enhancing the detection capabilities of non-destructive testing methods.
Implementation Method 1
exciting an object at a vibration frequency so as to induce at least one wave, having the vibration frequency, on an excitation surface of the object
Implementation Method 2
the at least one wave propagates into an analysis surface of the object
Implementation Method 3
use an optical interferometer to determine vibrational amplitude and phase of on a measurement surface of the object relative to a reference phase
Implementation Method 4
A processing system uses a spatial derivative filter to the vibration phase data, and the resulting spatial-derivate-of-phase data is processed to determine a property of the object
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a system and method of analysing an object. The method comprises exciting the object at a vibration frequency so as to induce at least one wave, having the vibration frequency, on an excitation surface of the object; propagate the at least one wave into an analysis surface of the object; measuring vibration on a measurement surface of the object, the measurement surface being spatially separated from the excitation surface of the object by the analysis surface of the object; processing the vibration data to determine a change in at least one wave property of the at least one wave; and determining, based on the change in the at least one wave property of the at least one wave, at least one defect existing in the analysis surface of the object.