6. Towards Faster Computations and Accurate Execution of Real-Time Hybrid Simulation

This chapter reports three recent developments aimed towards faster computations and more accurate execution of real-time hybrid simulations (RTHS). The first of these developments is a standalone RTHS system which can accommodate integration time steps as small as 1 ms. The fast execution feature eliminates the approximations that would be introduced by the application of a predictor-corrector smoothing technique and increases the applicability range of explicit integration methods. The second development is the use of an efficient equation solver in RTHS which reduces computation time. This efficient solver, which decreases the computation time by factorizing the Jacobian of the system of linear algebraic equations only once at the beginning of the simulation, is especially beneficial in RTHS which involves analytical substructures with large number of degrees of freedom (DOF). The third development is a novel use of a three-variable control (TVC) for RTHS on a shaking table configuration. Although the TVC, which employs velocity and acceleration control in addition to the typical displacement control, is commonly used in conventional shaking table tests, this development is the first application of TVC in RTHS.