Free vibration behavior of Ti-6Al-4V sandwich beams with corrugated channel cores: Experiments and simulations

Free vibration of ultralight all-metallic (Ti-6Al-4V alloy) sandwich beams with corrugated channel cores was investigated by experiments and finite element (FE) simulations. The natural frequencies and mode shapes were measured and compared with simulations from both three-dimensional model (3D model) and two-dimensional equivalent model (2D model). Predictions of the 2D model agreed well with results obtained from the 3D model and experiments. It was found that for sandwich beams, the topological change from corrugated core to corrugated channel core eliminates the anisotropy of the structural stiffness and suppresses the local modes of vibration. The effect of geometrical parameters on the first natural frequency was also explored. In addition, preliminary assessment of the influence induced by varying the core topology was carried out. The first natural frequency of sandwich beams with corrugated channel cores having an inclination angle theta > 45 degrees is higher than those of sandwich beams constructed with competing core topologies, including tetrahedral, Kagome and pyramidal trusses and hexagonal honeycombs.