Delamination Detection and Localization in Vibrating Composite Plates and Shells Using the Inverse Finite Element...

Area of Science:

• Materials Science
• Mechanical Engineering
• Structural Health Monitoring

Background:

• Delamination is a critical damage mode in composite materials, often lacking subtle surface indicators.
• Accurate detection of delamination is crucial for the safety and integrity of composite structures.

Purpose of the Study:

• To develop and demonstrate a delamination detection approach for vibrating composite plates using equivalent von Mises strains.
• To enable real-time monitoring and precise characterization of delamination damage.

Main Methods:

• Recasting governing relations of the inverse finite element method (IFEM) according to the refined zigzag theory.
• Utilizing in situ strain measurements from the surface and through-thickness.
• Reconstructing the strain field of composite shells via inverse analysis.

Main Results:

• Successful implementation demonstrated for harmonic and random vibrations of composite shells.
• The method accurately identifies the location, shape, and extent of delamination.
• The approach shows robustness against resonance and extreme load variations.

Conclusions:

• The proposed equivalent von Mises strain-based method provides effective real-time delamination detection in vibrating composite plates.
• This technique enhances structural health monitoring capabilities for composite materials.