Dynamic time-harmonic behaviour of smart patches on hygrothermalpiezoelectric substrates

• Applicant: Professor Dr.-Ing. Wilfried Becker
• Subject Area: Mechanics ; Lightweight Construction, Textile Technology
• Term: from 2016 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 317044714

The aim of the proposed research work is the analysis and assessment of the time-harmonic behaviour of a smart hygropiezothermal patch on a hygrothermalpiezoelectric substrate layer. The analysis includes the consideration of possible delamination of the patch from the substrate layer under respective load cases. For the intended investigation the shear lag model will be applied to reduce the governing system of two-dimensional equations of elasticity to a one-dimensional dynamic system of equations for the axial stresses and displacements of the given patch/substrate configuration. The differential equations for temperature, electric displacement and moisture will be also reduced to one-dimensional equations. Further the interfacial debond length of delaminations emanating from the left and right sides of the overlap zone of the configuration will be determined. A further aim is the identification of a possible criterion for detecting the interface debond length via the respective value of the electric gradient at fixed loading, material and geometric characteristics. For the practical application safety intervals of the model parameters as well as the safety zones of the work regime will be calculated via a genetic algorithm (GA). Some starting point of the consideration on the fatigue life of the smart lightweight structure will be also proposed on the basis that fatigue failure is brittle in nature.

• DFG Programme: Research Grants