Analysis of dynamic instability in sandwich thick beams with flexible functional core subjected to a follower force

Document Type : Research Article

Authors

1 Department of Mechanical Engineering, Shahid Rajaee Teacher Training University (SRTTU), Tehran, Iran

2 Aerospace research institute, Malekashtar university of Technology, Tehran, Iran

Abstract

Aerial structures under non-conservative forces especially follower loads, may be exposed to dynamic or static instabilities. Thus, it is essential to design these structures so that it would prevent this phenomenon. In this paper, for the first time, dynamic instability of a thick sandwich beam with flexible core under follower force is considered using high-order theory of sandwich beams. In the present paper, shear and normal core plate stresses are also considered, which have been ignored in higher-order sandwich panel theory and improved higher-order sandwich panel theory. The sandwich beam consists of two surfaces and a flexible core. The common surface of the core with the surfaces comprises a complete connection, capable of withstanding shear and vertical stresses. Sandwich beam is considered as a linear elastic structure with small rotations and deformations. Equations of Motion of high-order sandwich beams under follower force, are derived using Hamilton’s principle. The Beam fluttering phenomenon is investigated by applying boundary conditions and using a generalized differential quadrature method. in addition to the verification of results, effects of the beam’s geometry and mechanical parameters have been studied. These results revealed that the threshold flutter force of the sandwich beam is similar to Timoshenko one.

Keywords

Main Subjects


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