Fluid-shell interaction modeling is a challenging problem with application to
several engineering fields. In this research we develop a partitioned algorithm for large
displacements fluid-shell coupling with impact. The structure is modeled in a total Lagrangian
description, using a novel shell finite element formulation to deal with geometric
nonlinear dynamics of thin or thick shells. This formulation is based on the principle of
minimum potential energy considering positions and generalized unconstrained vectors as
nodal parameters, instead of displacements and rotations. As a consequence, the formulation
eliminates the need for large rotation approximations and presents constant mass
matrix, allowing the use of Newmark time integrator for the nonlinear problem. The
Newton-Raphson method is employed to solve the resulting nonlinear system and contact
between structures is modeled by enforcing non-penetration conditions based on a signed
distance function. The flow is assumed to be compressible and the fluid dynamics solver is
explicit with time integration based on characteristics. The fluid governing equations are
written in the Eulerian description generating a fixed mesh method. The coupled problem
is solved by using an embedded boundary technique where the fluid-shell interface
is tracked inside the unstructured fluid mesh by level sets of a signed distance to boundary
function. The versatility and efficiency of the proposed approach is demonstrated by
selected three- dimensional examples.
