Development and validation of a composite finite element with damping capability

This paper presents development and validation of a new composite Finite Element (FE) with damping capability. The damping capability is added to the composite shell element with physical drilling degrees of freedom by means of complex element stiffness matrix of the individual layers. The formulation is implemented in a FE code that allows modelling damped structures and performing modal analysis of the resulting complex eigenvalue problem. Some test cases are prepared and frequency response functions are measured in order to validate the predictions. The material properties used in the sample structures are identified experimentally using the Oberst Beam Method. Furthermore, the results obtained using the proposed composite FE are compared with those based on modal strain energy method. Comparisons of the experimental and the theoretical results confirm that the damping levels and the natural frequencies of damped structures can be predicted with high accuracy using the proposed formulation. (C) 2012 Elsevier Ltd. All rights reserved.