Complex modes expansion with vector projection using power flow to simulate Lamb waves scattering from horizontal...

Area of Science:

• Materials Science
• Mechanical Engineering
• Non-Destructive Testing

Background:

• Lamb waves are crucial for non-destructive testing of plate-like structures.
• Accurate modeling of wave scattering from defects like cracks and disbonds is essential for reliable inspection.
• Existing methods can be computationally expensive or lack versatility.

Purpose of the Study:

• To present an inexpensive and accurate analytical method for calculating Lamb wave scattering.
• To demonstrate the method's applicability to cracks parallel to the plate surface and disbond problems.
• To verify the method's accuracy and efficiency against established techniques.

Main Methods:

• Introduced a novel technique termed 'complex modes expansion with vector projection' (CMEP).
• Expanded the scatter field using complex Lamb wave modes with amplitudes determined by vector projection.
• Projected stress conditions onto displacement eigen-spaces and vice versa to solve for unknown amplitudes.

Main Results:

• CMEP accurately predicts Lamb wave scattering from horizontal cracks in plates.
• Results show excellent agreement with the finite element method (FEM) over a wide frequency-thickness range (up to 1.5 MHz mm).
• CMEP is orders of magnitude faster than FEM, offering significant computational efficiency.

Conclusions:

• The CMEP method provides a versatile and efficient analytical tool for analyzing Lamb wave-structure interactions.
• CMEP is applicable to various defect types, including cracks, corrosion, and disbonds.
• This method offers a computationally advantageous alternative to FEM for Lamb wave scattering analysis.