Determination of the effective Young's modulus of cellular materials from hollow bronze spheres by means of dynamic resonant method

摘要

Cellular materials from hollow bronze spheres were prepared and investigated. The main aim was to determine the effective Young's modulus of cellular materials by means of the dynamic resonant method, and the next goal was to demonstrate the possibility of using sandwich samples for such determination. For this purpose, two kinds of samples were prepared: quasihomogeneous rods consisting entirely of a cellular material, and sandwich rods containing the cellular material only in a core. Resonant frequencies of the fundamental flexural modes of all these samples were measured, and corresponding flexural rigidities were evaluated. Obtained values of flexural rigidities were subsequently utilized for calculation of the effective Young's modulus of cellular material. A reasonable agreement between the modulus values determined by means of quasihomogeneous and sandwich samples was obtained. This indicates that the sandwich samples could be used for measuring the material properties of particular layers.