ELL for 3D FSI problems with thin flexible structures based on the continuum-based shell element

This paper extends the Eulerian-Lagrangian-Lagrangian (ELL) method to solve the three-dimensional (3D) fluid-structure interaction (FSI) problems with flexible thin solids. The continuum-based (CB) shell element is adopted to model the flexible, thin-shell structure that undergoes large deformation. Several benchmarking problems, including a 3D cylinder-beam problem, vertical beam bending, and flapping flag, are solved to validate the present ELL approach incorporates the CB shell model. The results show that the ELL approach in this work has good agreement with references. A flapping butterfly with flexible wings is calculated to show the capability of the ELL to analyze more complex FSI problems in biomechanics. (C) 2021 Elsevier Ltd. All rights reserved.