Papers by Author: M.H. Yas

Abstract: Elasticity solution is presented for simply-supported, orthotropic, piezoelectric cylindrical shell with finite length under local ring load in the middle of shell and electrostatic excitation. The highly coupled partial differential equations (p.d.e.) are reduced to ordinary differential equations(o.d.e.) with variable coefficients by means of trigonometric function expansion in longitudinal direction for displacement and external forces. The resulting ordinary differential equations are solved by Galerkin finite element method. Numerical examples are presented for [0/90/P] lamination with sensor and actuator for different thicknesses.

Abstract: This work deals with fundamental frequency optimization in Multi-Layered laminated composite cylindrical shell which is subjected to strength failure criteria (Tsai-Hill) constraint. Anisotropic cylindrical shell has finite length with simply supported conditions at both ends. Three dimensional elasticity approaches is used to obtain the objective functioin. To perform optimization, genetic algorithms (GAs) have been used. But GAs does not have the capability of constraint handling. In this paper penalty method as an auxiliary method for GAs has been used to take into accounts the constraints. Tsai-Hill criteria is used as failure constraint. Finally the results are presented for a multi-layered composite shell.