Bending analysis of laminated and sandwich composite reissner-mindlin plates using nurbs-based isogeometric approach

Isogeometric analysis (IGA) is designed to combine computer-aided design (CAD) and finite element analysis (FEA) so that it significantly reduce the error in the representation of the computational domain. In the present work, a numerical procedure based on the framework of IGA for bending analysis of laminated and sandwich composite plates using the first-order shear deformation theory is described. In FEA, Lagrange or Hermit polynomial is used to approximate both the geometry and the solution field but IGA employs non-uniform rational B-splines (NURBS) from CAD technology to this objective. Hence considering geometry modelling, IGA have the advantage of no geometric error. Also, increasing the order of the elements in IGA gives higher continuous basis functions than FEA while maintaining few degrees of freedom. Therefore, isogeometric approach utilizes NURBS to implement for the quadratic, cubic, and quartic elements. Bezier extraction operator is used to ease the integration of NURBS in an existing finite element data structures. Several numerical examples are presented to show the performance of the current approach, and the results obtained are compared with analytical and other numerical methods. NURBS elements display the same convergence rate as Lagrange elements of equal order, with higher accuracy. (C) 2017 The Authors. Published by Elsevier Ltd.