Damage localization in composite structures with smoothly varying thickness based on the fundamental antisymmetric adiabatic wave mode

•Damage localization in composite structures with smoothly varying cross-section.•Generalized beamforming formulation for complex technical structures.•Structural health monitoring based on fundamental antisymmetric adiabatic wave mode.•Analysis of adiabatic wave motion in structures with irregular waveguides.

This work is based on the experimental observation that the phase and group velocity of the fundamental antisymmetric wave mode in a composite structure with linearly varying thickness changes as it propagates along the nonuniform waveguide (Moll et al., 2015). This adiabatic wave motion leads to systematic damage localization errors of conventional algorithms because a constant wave velocity is assumed in the reconstruction process. This paper presents a generalized beamforming approach for composite structures with nonuniform cross section that eliminates this systematic error. Damage localization results will be presented and discussed in comparison to existing techniques.