Digital twins, an innovative technology propelled by data and models, play a seminal role in the digital transformation and intelligent upgrade of ships. This study introduces a digital twin methodology for the real-time monitoring of ship structure deformation fields, based on finite discrete strain data, and a visualization tool framework is developed using virtual reality technology. First, the inverse Finite Element Method (iFEM) is employed to derive the deformation field of the ship structure in real time using sensor strain data. Secondly, the deformation field data obtained based on the iFEM algorithm is converted into general visualization data conducive to interpretation within virtual reality (VR) applications. Lastly, a digital twin software tool is built to enable synchronous responses and interactions between the virtual scene and the physical scene, directly superposing particular virtual objects (data acquired by sensors, computer-aided design (CAD) virtual models, and deformation field cloud images) onto the physical scene in real time. The digital twin tool embodies a virtual reality visualization system framework integrating the physical data measurement, reconstruction, analysis, expression, storage, rendering, and interaction of deformation field data. Through practical application, the flexibility, effectiveness, and compatibility of the developed prototype tool are verified. According to the results, the system can enhance the efficiency of scientific communication, model validation, and interdisciplinary sharing during the analysis and evaluation of the mechanical properties of ship structures.

In this paper, we describe a model test to investigate the hydrodynamic response of a newly designed pontoon-type floating bridge under regular waves. The displacement of each module, the bending moment along the entire floating bridge and the mooring force were obtained. Obvious nonlinear hydroelastic effects can be found by analysing the bending moments for different wave heights, which might result from such factors as nonlinear connectors, nonlinear mooring or nonlinear hydrostatic restoring force. This finding indicates that nonlinear factors have a significant effect on bending moment and should be taken into account in the design of floating bridges.

The dynamic buckling of rectangular plates with the elastically restrained edges subjected to in-plane impact loading is investigated. Budiansky–Hutchinson criterion is employed for calculation of dynamic buckling loads. The displacement function concluding the elastically restrained boundary condition is expressed as Navier’s double Fourier series. In order to solve the large deformation equations of plate, Galerkin method is applied. Also, the non-linear coupled time integration of the governing equation of plate is solved by using fourth-order Runge–Kutta method. The correctness of the method presented in the paper has been validated by comparing the results with the published literature. It is proved that the rotational restraint stiffness that is usually ignored by previous researchers plays an important role in dynamic response and dynamic buckling of the rectangular plates subjected to in-plane impact loading. Furthermore, the influence of the other parameters (initial imperfections, impact duration and geometric dimensions) on the dynamic response and dynamic buckling is studied in detail.

Based on the spring–mass model, a novel mechanical model of sloshing with fluid–structure interaction under a horizontal excitation is proposed, and the coupled dynamic equation of sloshing system is established. Considering the flexibility of bulkhead, the effects of certain factors, such as bulkhead bending stiffness and filling ratios, on the mode of coupled sloshing system are investigated. It is found that these factors have significant influence on the mode. By comparing the present results with the results of ADINA based on the linear potential flow theory and published literatures, the proposed coupled sloshing model is verified. The results show that the simplified rigid mass, $m_0$ , dominates the contributions to bending moment near the bottom of a bulkhead and the spring–mass, $m_1$ , $k_1$ , to bending moment near the liquid-free surface of a bulkhead. Furthermore, the computational cost is greatly reduced by using the proposed mechanical model with fluid–structure interaction for a rectangular tank sloshing.