An Impedance-Based Internal Force Coordination Control Method for Dual-Shaking Table Arrays

Shaking tables are critical facilities for simulating seismic effects via ground motion reproduction. However, single-table tests are often constrained by limited platform dimensions and load capacity. While multi-table synchronization overcomes these bottlenecks, traditional array control methods under rigid connections face challenges, including degraded precision from desynchronization and experimental interruptions due to output forces exceeding safety limits. To address high-precision synchronization requirements for rigid-connected dual-table arrays, this study proposes an impedance-based internal force coordination control strategy. This approach enhances synchronization accuracy and prevents failures from excessive coupling forces. Specifically, a global simulation model and a mechanical model of the dual-shaking table array under rigid connection were established. Through simulation and experimental validation, the impact of synchronization errors was evaluated and the strategy's efficacy verified. Results show the strategy significantly reduces force discrepancy between platforms. In simulation and experiments, average force discrepancy reductions reached 95.4% and 76.1%, respectively. Both displacement reproduction accuracy and synchronization precision improved. The method effectively circumvents experimental bottlenecks, such as output force saturation, inherently associated with rigid connections.