Speaker
Description
In this work, we modelled and simulated long-term damage in a fluid-structure interaction problem under a cyclic-in-time fluid regime. A temporal multiscale technique is proposed to efficiently compute the accumulation of internal damage under prolonged periodic loading conditions. This effect eventually manifests as macroscopic defects, such as cracks, or leads to failure. The study and modelling of these damage accumulation processes are addressed through the so-called concept of Continuum Damage Mechanics (CDM)(Lemaitre and Chaboche, 1994). The coupled dynamics are driven by the fluid and structural stresses, as well as the effective stress of the structure (a homogeneous elasticsolid), which is considered the main source of damage. We consider an elastic object attached to the bottom of a flow channel. The flow is driven by a periodic inflow boundary at the left of the channel and an open boundary at the right, which is assumed reminds unchanged over time. A Variational Multiscale Method (VMM) (Guo and Lin, 2015) was applied to efficiently compute the problem, leveraging the isolation of the periodic-in-time fluid-structure interaction fast-scale part of the problem, which allows larger time-stepping of the averaged slow-scale damage process. The spatial domain is considered Arbitrary Lagrangian Eulerian (ALE) coordinates. The computational time is drastically reduced by a magnitude of 10e4, enabling the fitting of the parameters of the damage model to literature or experimental data using a novel gradient-based method (Dominguez et al., 2023), as shown as part of preliminary results. The purposed approach not only demonstrates a variational multiscale methodology for coupling fluid-structure interaction problems with structural damage but also introduces the starting point for a temporal multiscale gradient-based fitting procedure specifically designed for this kind of problem.
