A space–time discontinuous Galerkin method for linearized elastodynamics with element-wise momentum balance

Abstract

We present a new space–time discontinuous Galerkin finite element method for linearized elastodynamics that delivers exact balance of linear and angular momentum over every space–time element. The method is formulated for use with fully unstructured space–time grids and uses displacement basis functions that are discontinuous across all inter-element boundaries. We introduce a new space–time formulation of continuum elastodynamics that uses differential forms and the exterior calculus on manifolds to generate a system of space–time field equations and jump conditions. Then we invoke a Bubnov–Galerkin weighted residuals procedure to formulate the finite element method. We describe an implementation on patch-wise causal meshes that features linear complexity in the number of elements and special per-pixel accurate visualization. Numerical examples confirm an a priori error estimate and demonstrate the method’s shock-capturing capabilities.