Digital twins for the underwater shake table array facility

Abstract

In this study, the three‐dimensional six‐degree‐of‐freedom underwater shaking table array facility for seismic simulation, which is built in Tianjin University, China, is taken as the research object. A digital twin of the shaking table is constructed. First, the components of the underwater shaking table array are introduced. And the simplified mechanical property of different components is illustrated. By using the system identification algorithm based on the measured dynamic responses, the basic model parameters, including the dynamics of the servo‐valve, the horizontal and vertical effective mass, the effective stiffness and damping coefficient of the actuators, the accumulators, and the friction of each actuator in the system are identified. The suitability of various experimental data sets used to identify the digital twin's model parameters is described. The prediction of various shaking table testing instances, as well as the comparison of digital twin and real system performance, are then presented. The digital twins shaking table system's performance and accuracy are examined. The shaking table's performance for various reproduction signals is compared to the digital twins model, which validates the suggested model's feasibility. Finally, the digital twins model is adopted and tried to tune the facility offline meanwhile the shaking table facility is configured iteratively. These findings highlight the applicability of the digital twins technique, which is the next research direction.

Strategy of scaled modeling for underwater shaking table tests on cylindrical marine structures under coupled earthquake and wave–current action: A review

“…UST in PARI 32 UST at DUT 33 LHGF in PARI 34 UST at HHU 35 USTAS at TJU 28,29 USTAS in NFEES 31,36 Following this, a similar scaled full rigid-frame bridge model with the same scaled modeling method, as shown in Figure 5A, was utilized by Wei et al 50 to investigate the effects of water depth and superstructures on the frequencydomain dynamic responses of the bridge. Given that structures entering the yield phase may have lower tangent modulus and larger deformations, the elasticity similitude criterion may be not suitable due to the neglection of P-Δ effects.…”

“…18 leakage and component aging of the early devices, their service life is relatively short. 29 At present, six USTs are in service or being built in the world (as shown in Figure 3). They are located at the Port and Airport Research Institute (PARI, Japan), Dalian University of Technology (China), Hohai University (China), and Tianjin University (China).…”

“…27 The UST consists of five main parts: the wave-making/attenuation system, the platform and supporting system, the actuation system, the hydraulic power system, and the control system. 28,29 Japan is the first country to develop USTs, and their single/double-degree-of-freedom USTs can be traced back to the 1980s. 30 However, due to the F I G U R E 1 Seismic damage of deep-water bridges during the 2008 Wenchuan Earthquake in China: (A) Girder falling and pier crack of Miaoziping Bridge 16,17 , and (B) transverse damage of Caobo Bridge.…”

“…The UST is an essential facility for investigations into the performance of structures under coupled earthquake and wave–current conditions 27 . The UST consists of five main parts: the wave‐making/attenuation system, the platform and supporting system, the actuation system, the hydraulic power system, and the control system 28,29 . Japan is the first country to develop USTs, and their single/double‐degree‐of‐freedom USTs can be traced back to the 1980s 30 .…”

“…F I G U R E 3 USTs in the world: (A) UST in PARI, Japan, 32 (B) UST at Dalian University of Technology (DUT), China,33 (C) Large Hydro-Geo Flume (LHGF) in PARI, Japan,34 (D) UST at Hohai University (HHU), China,35 (E) UST array system (USTAS) at Tianjin University (TJU), China,28,29 and (F) USTAS in NFEES (being built), China 31,36. NFEES, national facility for earthquake engineering simulation; PARI, Port and Airport Research Institute; UST, underwater shaking table; USTAS, UST array system.…”