Dynamics and damping in thin riveted beam composite structures.

      Аннотация: DYNAMICS AND DAMPING OF THIN RIVETED BEAM COMPOSITE STRUCTURES OF VARIOUS CONFIGURATIONS A comprehensive theoretical study of dynamics and damping of composite structures consisting of two or more layers of thin beams connected by an array of rivets and with fixed-fixed, fixed-simply supported and simply supported-simply supported boundary conditions have been made using classical energy approach and finite element method. In the first case, an analytical exact solution for the motion as well as natural frequencies and normal modes of such structures have been determined. Damping properties have been evaluated due to friction at the interfaces. In the later case, the equation of motion involving reduced mass and stiffness matrices using one dimensional beam elements have been derived and solved to find dynamic characteristics. Dissipated energy and stored energy determined in terms of nodal displacements have been used to find damping factor of beams. An experimental setup has been developed to measure dynamic and damping properties of prepared beam specimens with considered boundary conditions. Comparison of the results shows close agreement.

Ключевые слова: Composite, FEM, Modal Analysis, vibration, Structural damping, micro slip, LASER vibrometry, rivet, thin beam