[Paper Review] An open-source finite volume toolbox for solid mechanics and fluid-solid interaction simulations

Philip Cardiff, Aleksandar Karač+5 more|arXiv (Cornell University)|Aug 31, 2018

Advanced Numerical Methods in Computational Mathematics43 references67 citations

TL;DR

It presents solids4foam, an open-source solid mechanics and fluid-solid interaction toolbox built on OpenFOAM, emphasizing modular, object-oriented design and extensibility with comparisons to FE solutions.

ABSTRACT

Over the past 30 years, the cell-centred finite volume method has developed to become a viable alternative to the finite element method in the field of computational solid mechanics. The current article presents an open-source toolbox for solid mechanics and fluid-solid interaction simulations based on the finite volume library OpenFOAM. The object-oriented toolbox design is outlined, where emphasis has been given to code use, comprehension, maintenance and extension. The toolbox capabilities are demonstrated on a number of representative test problems, where comparisons are given with finite element solutions.

Motivation & Objective

• Motivate the need for open-source, integrated solid mechanics and FSI tools within a finite volume framework.
• Describe the solids4foam toolbox design that enables modular, extensible development in OpenFOAM.
• Demonstrate capabilities through representative test problems and compare results with finite element solutions.
• Promote open collaboration and maintainable code design for multi-physics simulations.

Proposed method

• Proposes a modular, object-oriented class structure to encapsulate physics models for solids, fluids, and FSI within OpenFOAM.
• Implements solution methodologies such as PISO for fluids and nonlinear geometry approaches for solids within a unified framework.
• Adopts an abstract Physics Model base class with derived Solid Model, Fluid Model, and Fluid-Solid Interaction Model classes to enable runtime interchangeability.
• Supports both linear geometry (small strains/rotations) and nonlinear geometry (finite strains) through multiple constitutive laws.
• Uses cell-centered finite volume discretisation and leverages TL (total Lagrangian) and UL (updated Lagrangian) formulations for solid momentum equations.
• Emphasizes software engineering practices including coding standards, Git revision control, and Doxygen documentation to ensure usability and maintainability.

Experimental results

Research questions

• RQ1 Can an open-source, modular finite volume toolbox within OpenFOAM support diverse solid mechanics and fluid-solid interaction problems with extensible constitutive models?
• RQ2 How does a unified solids4foam design perform on representative test problems compared to finite element solutions?
• RQ3 What software engineering practices are necessary to maintain and extend an open-source CSM/FSI toolbox in a multi-developer environment?

Key findings

• Introduces solids4foam as an open-source toolbox enabling generalised solid mechanics and FSI within OpenFOAM.
• Demonstrates a modular class structure that supports multiple solid and fluid models and runtime switching between geometries and solution methodologies.
• Highlights the ability to implement both linear and nonlinear geometry constitutive laws and to couple them within a common framework.
• Shows that the toolbox is designed for usability, understandability, maintainability, and extendability, with strict coding standards and revision control.