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Cardiff, Philip
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Cardiff, Philip
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Cardiff, Philip
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Now showing 1 - 6 of 6
- PublicationAn open-source finite volume toolbox for solid mechanics and fluid-solid interaction simulations(2018)
; ; ; ; 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.1169 - PublicationDevelopment of mapped stress-field boundary conditions based on a Hill-type muscle model(Wiley Blackwell (John Wiley & Sons), 2014-04-07)
; ; ; Forces generated in the muscles and tendons actuate the movement of the skeleton. Accurate estimation and application of these musculotendon forces in a continuum model is not a trivial matter. Frequently, musculotendon attachments are approximated as point forces; however, accurate estimation of local mechanics requires a more realistic application of musculotendon forces. This paper describes the development of mapped Hill-type muscle models as boundary conditions for a finite volume model of the hip joint, where the calculated muscle fibres map continuously between attachment sites. The applied muscle forces are calculated using active Hill-type models, where input electromyography signals are determined from gait analysis. Realistic muscle attachment sites are determined directly from tomography images. The mapped muscle boundary conditions, implemented in a finite volume structural OpenFOAM (ESI-OpenCFD, Bracknell, UK) solver, are employed to simulate the mid-stance phase of gait using a patient-specific natural hip joint, and a comparison is performed with the standard point load muscle approach. It is concluded that physiological joint loading is not accurately represented by simplistic muscle point loading conditions; however, when contact pressures are of sole interest, simplifying assumptions with regard to muscular forces may be valid.660Scopus© Citations 4 - PublicationA large strain finite volume method for orthotropic bodies with general material orientationsThis paper describes a finite volume method for orthotropic bodies with general principal material directions undergoing large strains and large rotations. The governing and constitutive relations are presented and the employed updated Lagrangian mathematical model is outlined. In order to maintain equivalence with large strain total Lagrangian methods, the constitutive stiffness tensor is updated transforming the principal material directions to the deformed configuration. Discretisation is performed using the cell-centred finite volume method for unstructured convex polyhedral meshes. The current methodology is successfully verified by numerically examining two separate test cases: a circular hole in an orthotropic plate subjected to a traction and a rotating orthotropic plate containing a hole subjected to a pressure. The numerical predictions have been shown to agree closely with the available analytical solutions. In addition, a 3-D composite component is examined to demonstrate the capabilities of the developed methodology in terms of a variable material orientation and parallel processing.
990Scopus© Citations 42 - PublicationDevelopment of a Hip Joint Model for Finite Volume Simulations(ASME International, 2013-12-03)
; ; ; This paper establishes a procedure for numerical analysis of a hip joint using the finite volume method. Patient-specific hip joint geometry is segmented directly from computed tomography and magnetic resonance imaging datasets and the resulting bone surfaces are processed into a form suitable for volume meshing. A high resolution continuum tetrahedral mesh has been generated, where a sandwich model approach is adopted; the bones are represented as a stiffer cortical shells surrounding more flexible cancellous cores. Cartilage is included as a uniform thickness extruded layer and the effect of layer thickness is investigated. To realistically position the bones, gait analysis has been performed giving the 3D positions of the bones for the full gait cycle. Three phases of the gait cycle are examined using a finite volume based custom structural contact solver implemented in open-source software OpenFOAM.958Scopus© Citations 14 - PublicationDevelopment of a finite volume contact solver based on the penalty methodThis paper describes the development and application of a frictionless contact stress solver based on the cell-centred finite volume method. The contact methodology, implemented in the open-source software OpenFOAM, is derived from the penalty method commonly used in finite element contact algorithms. The solver is verified on two benchmark tests using the available Hertzian analytical solutions.
935Scopus© Citations 36 - PublicationHierarchical RVE-based multiscale modelling of non-linear heterogeneous materials using the finite volume methodThis paper describes the development of a hierarchical multiscale procedure within the finite volume OpenFOAM framework for modelling the mechanical response of non-linear heterogeneous solid materials. This is a first development of hierarchical multi-scale model for solid mechanics to use the finite volume discretisation method. In this computational procedure the information is passed between the macro and micro scales using representative volume elements (RVE), allowing for general, non-periodic microstructures to be considered. Each computational point at the macro scale is assigned an RVE with prescribed microstructural features. The overall macro response accounts for the microstructural effects through the coupling of macro and micro scales, i.e., the macro deformation gradient is passed to the RVE and in turn, the homogenised micro stress-strain response is passed back to the macro scale. The incremental total Lagrangian formulation is used to represent the equilibrium state of the solid domain at both scales and its integral equilibrium equation is discretised using the cell-centred finite volume (FV) method in OpenFOAM. The verification of the model is demonstrated using both 2D and 3D simulations of perforated elastic-plastic plates subjected to tensile loading.
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