A continuum and computational framework for viscoelastodynamics: II. Strain-driven and energy-momentum consistent schemes

We continue our investigation of finite deformation linear viscoelastodynamics by focusing on constructing accurate and reliable numerical schemes. The concrete thermomechanical foundation developed in the previous study paves the way for pursuing discrete formulations with critical physical and mathematical structures preserved. Energy stability, momentum conservation, and temporal accuracy constitute the primary factors in our algorithm design. For inelastic materials, the directionality condition, a property for the stress to be energy consistent, is extended with the dissipation effect taken into account. Moreover, the integration of the constitutive relations calls for an algorithm design of the internal state variables and their conjugate variables. A directionality condition for the conjugate variables is introduced as an indispensable ingredient for ensuring physically correct numerical dissipation. By leveraging the particular structure of the configurational free energy, a set of update formulas for the internal state variables is obtained. Detailed analysis reveals that the overall discrete schemes are energy-momentum consistent and achieve first- and second-order accuracy in time, respectively. Numerical examples are provided to justify the appealing features of the proposed methodology.(c) 2023 Elsevier B.V. All rights reserved.

Automated summary

This study investigates the numerical schemes of finite deformation linear viscoelastodynamics, focusing on accuracy and reliability. The proposed algorithm preserves critical physical and mathematical structures, ensures energy stability, momentum conservation, and temporal accuracy. The directionality condition and integration of constitutive relations are considered for inelastic materials, leading to physically correct numerical dissipation. The update formulas for internal state variables based on the configurational free energy demonstrate energy-momentum consistency and achieve first- and second-order accuracy in time. Numerical examples support the effectiveness of the methodology.