Effect of Axial Loading on Vibration of Elasto-Plastic Sandwich Cylindrical Shells

In this paper the vibration analysis of a sandwich cylindrical shell in elastic-plastic domain is considered. In contrast to most of the available sandwich shell analyses, the elastic-plasticbehaviors of materials are included in the presented formulation. The sandwich shell is consistingof three layers; two faces and one core. The faces are made of an isotropic materialwith linear work hardening behavior and the core is made of an orthotropic elastic material.The faces are modeled as thin cylindrical shells obeying the Kirchhoff-Love assumptions. The core material is modeled as special orthotropic elastic solid possessing shear stiffnessesonly, whereas it is assumed that the axial and circumferential stiffnesses are negligible. Thecore is also assumed to be incompressible in thickness direction. The shell is placed on simplysupported end constraints and the acting load is in the form of longitudinal force. The incrementalPrandtl-Reuss plastic flow theory and von Mises yield criterion are used in the analysis. The governing equations are derived using Hamilton’s principle of the minimizationof the Lagrangian of the deformed system. Using appropriate displacement functions basedon the boundary conditions, and solving the obtained eigenvalue problem, the numerical results obtained for different values of parameters. The method presented herein enables the study of the effects of external loading on the vibration of cylindrical sandwich shells, including also the determination of the buckling loads.

Keywords:

Free vibration , Sandwich cylindrical shell , Elasto-plastic