Shear lag analysis of dynamically loaded smart patch/substrate structures with interface defects

• Applicant: Professor Dr.-Ing. Wilfried Becker
• Subject Area: Mechanics
• Term: from 2017 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 385584145

The research objectives can be summarized as follows:1. To obtain the simple coupled system of ordinary differential equations for the dynamic time harmonic behaviour of a smart hygropiezothermal patch/layer structure with preliminary given location of an interface void from the 2D system of partial differential equations. The possible interface elastic brittle delamination will be studied under the satisfied restriction for energy release ratio related to the first appearance of mode II along the interface. 2. The shear lag model will be applied to reduce the 2D theory of elasticity to a 1D dynamic system of equations for the axial stresses and displacements of the piezoelectric smart structure for all three zones along the interface. For this purpose an appropriate modelling will be performed for the given interface defect. Further depending of the location of the interface void, the debond interfacial length appearing from the left or/and right sides of the overlap zone of the structure will be determined. The possible criterion for detecting the interface debond length by the respective value of the electric gradient at fixed loading, material and geometric characteristics will be proposed. On the base of the optimal analysis, the optimal structure with a restriction for an absence of interface delamination will be proposed.

• DFG Programme: Research Grants
• International Connection: Bulgaria
• Cooperation Partners: Professorin Dr. Jordanka Ivanova; Professorin Dr. Elisaveta Kirilova; Professorin Dr. Tatyana Petrova