Hybrid Global Matrix/Local Interaction Simulation Approach (LISA) Model for GW SHM in Composite Laminates

Student :

Sponsors :

Matt Obenchain

National Rotorcraft Technology Center (NTRC) Vertical Lift/Rotorcraft Center of Excellence (VLRCOE)

Summary:

As the use of composites increases in new aerospace systems, the ability to detect and characterize damage in advanced materials will be vital to the successful maintenance and employment of new systems. The use of guided elastic waves to detect damage has shown great promise for isotropic metal structures, and it is expected this methodology will also work in composites. However, additional study is required to completely characterize how guided waves propagate in anisotropic structures and how they interact with typical damage modes in composite laminates.

Objectives:

  • Produce highly accurate time histories for GW propagation using the global matrix method

  • Develop a hybrid modeling tool using the global matrix method to capture the behavior of a PZT actuator and LISA to model wave propagation in pristine and damaged structures

  • Use modeling and experimentation to characterize Lamb wave interaction with types of damage likely to be found in fielded composite structures.

alumdamage

 

 

The out-of-plane displacement field in an aluminum plate is shown 80 μs after the start of an actuation pulse. The actuation pulse is from a circular PZT actuator. Reflections from a damaged area are clearly visible on the right hand side.

timehistory

 

The time history of a point midway between the actuator and the damage site is compared to the signal from a pristine sample. Reflections from the damaged area are visible after 0.06 ms.

crossply

 

The out-of-plane displacement field in a cross-ply plate is shown 80 μs after the start of an actuation pulse. The actuation pulse is from a circular PZT actuator.