Advanced Modeling Techniques for Ultrasonic Guided Waves

Student : Dr. Yanfeng Shen

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


Summary:

A highly efficient hybrid modeling technique was developed for the efficient simulation of guided wave generation, propagation, and interaction with damage in complex composite structures.

  1. A local finite element model (FEM) was deployed to capture the piezoelectric effects and actuation dynamics of the transmitter, while the global domain wave propagation and interaction with structural complexity (structure features and damage) were solved utilizing a local interaction simulation approach (LISA).
  2. The global LISA framework was implemented using the Compute Unified Design Architecture (CUDA) running on Graphics Processing Unit (GPU).
  3. The global LISA framework was also extended through the 3-D Kelvin-Voigt viscoelasticity theory to include directional damping effects for composite structures.
  4. The 3-D LISA formulation was extended to capture the contact-impact dynamics based on the penalty method for the simulation of nonlinear interaction between guided waves and fatigue cracks.

Overview of hybrid local FEM/global LISA technique.
Guided wave propagation in a stiffened cross-ply CFRP composite plate with delamination (0-deg orientation along the plot horizontal direction)

Modeling of guided wave interaction with a breathing crack using LISA. (Note that the excitation centers at 100 kHz, while the sensing signal contains not only the fundamental frequency at 100 kHz, but also distinctive nonlinear higher harmonics at 200 kHz, 300 kHz, and 400 kHz, etc.)