A Coupled Lattice Boltzmann-Extended Finite Element Model for Fluid-Structure Interaction Simulation with Crack Propagation.

摘要

Fatigue cracking of structures in fluid-structure interaction (FSI) applications is a pervasive issue that impacts a broad spectrum of engineering activities, ranging from large-scale ocean engineering and aerospace structures to bio-medical prosthetics. Fatigue is a particular concern in the offshore drilling industry where the problem is exacerbated by environmental degradation, and where structural failure can have substantial financial and environmental ramifications. As a result, interest has grown for the development of structural health monitoring (SHM) schemes for FSI applications that promote early damage detection. FSI simulation provides a practical and efficient means for evaluating and training SHM approaches for FSI applications, and for improving fatigue life predictions through robust parametric studies that address uncertainties in both crack propagation and FSI response. To this end, this paper presents a numerical modeling approach for simulating FSI response with crack propagation. The modeling approach couples a massively parallel lattice Boltzmann fluid solver, executed on a graphics processing unit (GPU) device, with an extended finite element (XFE) solid solver. Two-way interaction is provided by an immersed boundary coupling scheme, in which a Lagrangian solid mesh moves on top of a fixed Eulerian fluid grid. The theoretical basis and numerical implementation of the modeling approach are presented, along with a simple demonstration problem involving subcritical crack growth in a flexible beam subject to vortex-induced vibration.