# Free vibration analysis of variable stiffness composite laminated thin skew plates using IGA

Document Type: Invited by Hamid Ahmadian

Authors

Aerospace research institute, Mahestan St., Tehran, Iran

10.22064/tava.2018.81281.1100

Abstract

A NURBS-based isogeometric finite element formulation is developed and adopted to the free vibration analysis of finite square and skew laminated plates. Variable stiffness plies are assumed due to implementation of curvilinear fiber
reinforcements. It is assumed due to employment of tow placement technology, in each ply of variable stiffness composite laminated plate the fiber reinforcement orientation angle is changed linearly with respect to longitudinal geometry coordinate. The classic plate theory is utilized for structural model description. The cubic NURBS basis functions are employed to approximate the geometry of the plate while simultaneously serve as the shape functions for solution field approximation in the analysis. To show the effectiveness and accuracy of the developed formulation, some representative
results are extracted and compared to similar items available in the literature. The effects of curvilinear fiber angles, different geometries and various end constraints are evaluated on the variable stiffness composite laminated skew panel behavior.

Highlights

• Dynamic characteristics of variable stiffness laminated composite skew plates are extracted.
• An Isogeometric Analysis formulation based on NURBS approximation functions is developed.
• The first implementation of IGA in analyzing skew panels made from VSCL materials.
• Cubic NURBS basis functions are employed to build both geometry and its numerical model.
• The effects of skew angle on the natural frequencies are clarified for different constraint sets

Keywords

Main Subjects

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