Dynamic Stability and Static Stress State of a Sandwich Beam with a Metal Foam Core Using Three Modified Timoshenko Hypotheses

The subject of the paper is simply supported sandwich beams with a metal foam core. The fields of displacement for the flat cross section of the beam are defined by three different hypotheses. The mechanical properties of the isotropic metal foam core of the beam are varied in a normal direction in relation to the middle symmetry plane. Basing on the Hamilton's principle the system of three partial differential equations of motion are obtained for each hypothesis. These systems are approximately solved. The results of solutions of the vibration problem will be compared and presented in Figures. Moreover, strength conditions of the layers joint will be formulated.