Fluid-structure interaction modelling of nonlinear aeroelastic structures using the finite element corotational theory

The application of the finite element corotational theory to model geometric nonlinear structures within a fluid-structure interaction procedure is proposed. A dynamic corotational approximately-energy-conserving algorithm is used to solve the nonlinear structural response and it is shown that this algorithm's application with a four-node flat finite element is more stable than the nonlinear implicit Newmark method. This structural dynamic algorithm is coupled with the unsteady vortex-ring method using a staggered technique. These procedures were used to obtain aeroclastic results of a nonlinear plate-type wing subjected to low speed airflow. It is shown that stable and accurate numerical solutions are obtained using the proposed fluid-structure interaction algorithm. Furthermore, it is illustrated that geometric nonlinearities lead to limit cycle oscillations. (c) 2005 Elsevier Ltd. All rights reserved.