Testing and simulation of skin materials for hybrid laminar flow control under bi-axial tension

Kurzfassung

The given report covers both tests and simulation of biaxial tension of airfoil skin materials. Initially, biaxial tension tests on specimens of two types were performed, namely micro-perforated titanium sheet metal and metal-mesh laminate with a foil. Both sheet materials are considered for application in leading edge demonstrators incorporating hybrid laminar flow control (HLFC). The quasi-static tests were performed to quantify failure strain. The force-displacement histories were recorded whereas the strain until onset of failure was measured using DIC (Digital Image Correlation). DIC was performed on all titanium specimens and steel mesh specimens. Simulations of the biaxial tension specimens were performed resembling the test and the material data was used to calibrated two material models in an explicit finite element modelling software. The differences between the two material models and their application was discussed. The finite element models with varying mesh types (fine, coarse, irregular meshes) and simulation parameters were considered and compared. The presented testing-simulation methodology can be used to obtain and validate skin material properties for impact simulation of full-scale demonstrators.