Numerically Stable Integrated Simulation Method for Coupled Dynamic Systems

Compared to monolithic simulation methods, integrated simulation methods allow decomposition of a large and complex system into several subsystems whose behavior can either be numerically or experimentally captured considering unique capabilities of existing analysis tools. Therefore, they have been applied to multi-physics problems and analysis of large-scale complex structural systems. However, there is still a lack of a robust integrated simulation method that can be easily implemented in existing analysis tools and also ensure numerical stability. In this study, a novel integrated simulation method is proposed that not only allows seamless data exchange based on standard input and output of subsystem programs but also can achieve unconditional stability by adjusting the time integration coefficients for the interface layers between the decomposed subsystems. The stability of the proposed method is mathematically evaluated through the energy approach. Numerical evaluations of the accuracy and stability limits of the proposed method are also presented. Two application examples are provided to demonstrate potential applications of the proposed approach.