Computationally efficient multi-time-step method for partitioned time integration of highly nonlinear structural dynamics

• Presented a new method for multi-time-step integration for highly non-linear problems.
• Dual-Schur domain decomposition is used with different time-steps between subdomains.
• Numerical examples show that method is stable, accurate and computationally efficient.
• Faster than using a single uniform time step for the entire mesh.
• Multi-scale application of a sandwich plate under projectile impact confirms results.

An efficient and accurate method for solving large-scale problems in non-linear structural dynamics is presented. The method uses dual-Schur domain decomposition to divide a large finite element mesh into a number of smaller subdomains, which are solved independently using a suitable mesh-size and time-step to capture the local spatial and temporal scales of the problem. Continuity of the solution between subdomains is enforced by Lagrange multipliers. It is shown that the proposed method is stable, accurate and computationally more efficient than using a uniform time-step for the entire mesh. Numerical examples are presented to illustrate and corroborate these properties.