Angle-Beam Guided Waves for Composite Damage Identification
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Solution Overview
Problem
Current guided wave-based structural health monitoring techniques face challenges in detecting composite damage types like impact damage and delaminations in composite materials due to the anisotropic behavior and complex wave-damage interaction phenomena, particularly in carbon fiber reinforced polymer (CFRP) structures, where existing methods are often expensive, labor-intensive, and difficult to interpret.
Innovation Solution
The use of adjustable angle beam transducers to achieve single-mode guided wave excitation, generating shear horizontal (SH0) waves, and employing trapped energy analysis to detect and differentiate between various damage types, including wrinkle damage, multilayer delaminations, and impact damage, by adjusting the tuning angle using an angle-adjustable wedge and calculating it via the equation sinθ = c / cw, where θ ranges from 0 to 70 degrees.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional guided wave techniques are used for composite damage detection, then damage can be detected, but the results are difficult to interpret due to complicated wave-damage interaction phenomena and anisotropic behavior
Solution Approach 1:
The patent changes the wave propagation parameter by using angle-beam excitation at specific angles (e.g., 45 degrees) to generate quasi-SH0 modes that are less sensitive to anisotropic effects. This parameter change simplifies the wave-damage interaction and makes results easier to interpret while maintaining damage detection capability
Solution Approach 2:
The patent introduces asymmetric excitation geometry by using angled beams rather than normal incidence, which creates specific mode patterns (quasi-SH0) that interact differently with damage types, thereby simplifying interpretation of delamination versus impact damage
2Loss of information
If multiple wave modes are excited at a given frequency, then more damage information can be obtained, but the complexity of wave interpretation increases
Solution Approach 1:
The patent extracts and isolates specific guided wave modes (quasi-SH0 and quasi-S0) by using angle-beam excitation at carefully selected angles. This extraction approach separates the desired damage-sensitive modes from other complex modes, reducing interpretation complexity while preserving essential damage information
Solution Approach 2:
The patent segments the complex wave field into distinct, identifiable mode components by using angular excitation to selectively generate quasi-SH0 and quasi-S0 modes. Each mode can be independently analyzed for specific damage types, simplifying overall interpretation
3Measurement precision
If traditional NDE techniques such as thermography and X-ray are used, then damage detection is achievable, but the process becomes expensive and labor-intensive
Solution Approach 1:
The patent replaces complex mechanical NDE systems (thermography equipment, X-ray apparatus) with a simplified guided wave-based mechanical excitation system using piezoelectric actuators and angle-beam transducers, reducing cost and labor while maintaining detection capability
Solution Approach 2:
The guided wave system uses the structure itself as the propagation medium and damage indicator, eliminating the need for separate imaging equipment and operators. The structure's own wave response provides the damage information, reducing external equipment requirements and operational complexity
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 method enables efficient detection and sizing of composite damage with significant amplitude drops, allowing for rapid large-area inspection and distinguishing between different damage types, reducing the need for labor-intensive local evaluations and improving the accuracy of damage identification in composite structures.
Implementation Method 1
Guided waves have the advantage of long-distance propagation in complex structures and low energy loss, which have been widely used in the structural health monitoring of composite structures
Implementation Method 2
generating a shear horizontal (SH0) wave
Implementation Method 3
the angle beam transducer (ABT) with wedge has been utilized to achieve tuned wave excitation and detection based on Snell's law
Data Source
AI summary
Detection, identification, and monitoring of various composite-damage types such as impact damage, delaminations, etc. using angle-beam coupled guided waves and methods and systems that permit excitation with angle-beam techniques of certain composite-material guided-wave modes that cannot be excited in isotropic metals with angle-beam methods.