Geometrically nonlinear isogeometric analysis of functionally graded plates based on first-order shear deformation theory considering physical neutral surface

This paper presents the geometrically nonlinear isogeometric analysis of functionally graded material (FGM) plates based on the first-order shear deformation theory considering the physical neutral surface. According to the power law distribution of volume fraction of constituents, the material properties of plate are assumed to vary through the thickness. The transverse shear correction factor is evaluated through the energy equivalence and the geometric nonlinearity is accounted for von Kármán strain for dealing with small strain and moderate rotation. The quadratic NURBS (Non-Uniform Rational B-Spline) elements are used to construct physical meshes in C1 continuity which is required for the generalized displacements. A numerical analysis is performed on the examples of square plates with various boundary conditions and clamped circular plate. The obtained results are compared with the previously published results in order to show the accuracy and effectiveness of present approach. The effects of shear correction factors, gradient index and different boundary conditions on the geometrically nonlinear deflection response of FGM plates are parametrically investigated.