A trimmed-NURBS-based thermal buckling isogeometric analysis framework for the variable stiffness plate with complex cutouts

The isogeometric analysis of variable-stiffness structures with curvilinear fibers has gained considerable research attention. However, dealing with structures that have complex cutouts poses challenges for isogeometric analysis. Additionally, the thermal-elastic behavior of variable-stiffness structures must be carefully considered, as they often operate in thermal environments. This study introduces a novel trimmed non-uniform rational basis spline (NURBS) method to address these challenges and investigate the thermal buckling behavior of variable-stiffness plates. The method generates trimmed NURBS elements using a level-set function on the initial NURBS mesh to describe complex geometries. Segmented density interpolation formulas are proposed to capture the contributions of different NURBS elements and to prevent localized eigenmodes. An artificial shear correction factor is introduced to mitigate shear locking. Several numerical examples with various boundary conditions and fiber configurations, are presented to demonstrate the high accuracy and low computational costs of the proposed method.