An industry-driven computational framework is proposed for the numerical simulation of large strain solid dynamics. This work focuses on the tailor-made implementation of the TOtal Lagrangian Upwind Cell Centred Finite Volume Method for Hyperbolic conservation laws (TOUCH) into the CFD-based open source platform OpenFOAM. Crucially, the proposed framework bridges the gap between CFD and large strain solid dynamics. The TOUCH scheme performs extremely well without posing any numerical instabilities.
Current computer codes (e.g. PAM-CRASH, ANSYS AUTODYN, LS-DYNA, ABAQUS, Altair HyperCrash) used in industry for the simulation of large-scale solid mechanics problems are typically based on the use of traditional second order displacement based Finite Element formulations. However, it is well-known that these formulations present a number of shortcomings, namely (1) reduced accuracy for strains and stresses in comparison with displacements; (2) high frequency noise in the vicinity of shocks and (3) numerical instabilities associated with shear (or bending) locking, volumetric locking and pressure checker-boarding. The proposed methodology tailor-made for emerging (industrial) solid mechanics problems overcomes the shortcomings mentioned earlier. The mixed-based approach is written in the form of a system of first order hyperbolic conservation laws, widely known in CFD community. The primary conservation variables of interest are linear momentum and deformation gradient.
A series of challenging numerical examples are examined in order to assess the robustness and accuracy of the proposed algorithm, benchmarking it against an ample spectrum of alternative numerical strategies. The TOUCH scheme shows excellent behavior in highly nonlinear nearly incompressible scenarios and overcomes the current drawbacks of existing industry computer codes.
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