Asynchronous time integration in structural mechanics

In some cases of structural dynamics problems, that are decomposed into substructures, it might be beneficial to have different time‐step‐sizes in each substructure. This is often referred to as asynchronous time‐integration. Since we want to extend our nonlinear FETI‐framework with such an asynchronous time‐integrator in the future, a Lagrange‐multiplier‐based framework should suit us best. As a first step we apply the PASTA‐DDM, which is based on a three‐field‐approach, to a simple linear heterogeneous multi‐mass‐oscillator and investigate the method's energy‐conservation properties. The integration is stable but slightly more energy is dissipated in the asynchronous case than in the synchronous one. Furthermore we solve the global interface‐problem and the local update of Lagrange‐multipliers with a residual‐based conjugate‐gradient method in order to prepare the PASTA‐DDM for an iterative parallel implementation.