Variable-stiffness curved laminated-beams by curvilinear fibers with arbitrarily layup - Vibrational features by sine-based higher-order beam model with renewed-constitutive relations and improved-kinematics

The vibration characteristics of variable-stiffness based composite curved beams with general layups are examined using a higher-order beam theory that accounts for three-dimensional structural response features. The variable stiffness is spatially considered in the laminated beam by introducing the curvilinear fibres-based layers. The structural model is here represented by a sine-based shear deformable model considering zig-zag function for improving in-plane response and higher order polynomial for capturing through-thickness stretching effect. The appropriate constitutive relationships for laminated composite curved beam with arbitrary layup producing stiffness coupling effects are deduced from three-dimensional elasticity equations. The beam governing equations are then formed applying Hamilton's principle and the free vibration features are predicted employing the eigenvalue analysis. The effectiveness of the curved laminated beam element developed here is tested against the available analytical solutions in the literature. A detailed numerical analysis by opting for different structural parameters like curved beam angle, thickness, ply-angle, layup, and beam end condition are made to investigate the vibration characteristics of general layup constant stiffness laminated curved beams and by including additional parameter, curvilinear fibre angle variation from centre-to-edge, for variable stiffness laminates.

Automated summary

This study examines the vibration characteristics of variable-stiffness based composite curved beams with general layups using a higher-order beam theory. The variable stiffness is achieved by introducing curvilinear fiber layers. The constitutive relationships for the laminated beam are deduced from three-dimensional elasticity equations, and the governing equations for the beam are formed using Hamilton's principle. The free vibration features are predicted through eigenvalue analysis. The effectiveness of the developed curved laminated beam element is tested against analytical solutions, and numerical analysis is conducted to investigate the vibration characteristics under different structural parameters.