Student : Hui Zhang
Sponsor : National Rotorcraft Technology Center (NTRC) Vertical Lift/Rotorcraft Center of Excellence (VLRCOE)
(Please refer to this page for more details)
Guided waves can detect hidden damage, such as fatigue in metallic plate or delamination in a composite. Since guided waves inside a structure are highly dispersive and have multi-modes, numeric simulation is usually required as a first step to develop insights and provide any guidelines in future applications. Local Interaction Simulation Approach (LISA) is a highly parallelizable numeric scheme for guided wave simulation and has been adopted by us in the hope of developing a powerful, versatile, and efficient software for guided wave simulation under different requirements.
This project focuses on incorporating non-reflective boundary (NRB) techniques in LISA, in order to simulate guided wave propagation in infinite domain with a finite size model, as well as developing a new LISA-based scheme to increase the accuracy of the simulation and tackle the issue of stability in LISA. The other area of interest is the simulation of local damage, created by the cracks or delamination existing in a structure. Two kinds of models, a contact model and a bilinear stiffness model are being developed, in order to simulate the phenomena of higher harmonics generation, sidebands, etc. This project will focus on developing the bilinear stiffness model, and validate the model through experiment using Scanning Laser Doppler Vibrometry (SLDV). It is expected that nonlinear waves will highlight the existence of local damage, and be able to provide better information about the location and severity of the damage.
Higher harmonics generation in beam modelling fatigue cracks.
Guided waves reflection from boundaries.
Guided waves simulation implementing non-reflective boundary.
Wave propagation inside a composite structure using new solver based on LISA.