MECHANICAL DAMPING PROPERTIES OF Al-Si CLOSED-CELL ALUMINUM FOAM

摘要

The mechanical damping properties of Al-Si closed-cell aluminum foam with various porosities were measured using the cantilevered beam mount based on a modified sample geometry. The measured loss factor shows that Al-Si closed-cell aluminum foam has a damping capacity which is independent of frequency and increases with increasing porosity when the cell size is kept constant. There is a critical strain amplitude εe. When strain amplitude is less than εe, the loss factor does not change with strain amplitude. When strain amplitude exceeds εe, the loss factor increases remarkably with increasing strain amplitude. A Voigt two-parameter model was introduced to explain the damping behavior of Al-Si closed-cell aluminum foam.