VFIFE based hybrid simulation for submerged floating tunnel research

Submerged floating tunnel (SFT) is an innovative traffic infrastructure in the underwater transportation system. It is necessary to analyze its dynamic response accurately, which is essential for indepth understanding of its complex dynamic behavior and can be verified by testing methods. Hybrid simulation (HS) is a quite powerful testing method by combining the numerical simulation and experimental testing, in which the testing structure is divided into two parts: a numerical part whose mechanical properties are simple and easy to analyze by numerical model, and an experimental part with complex mechanical behaviors that can only be accurately obtained through experiment. Therefore, hybrid simulation method can be applied into the researches about complex dynamic problems of SFT, for example, the performance of cable vibration mitigation and the effect of vehicle-tunnel-environmental coupling system. However, the numerical part is generally highly simplified to relieve the computation burden, which may cause the deviation between numerical model and real structure, especially when the whole testing structure is complex and the numerical part has a large number of degrees of freedom (DOFs). Thus, in this paper, the vector form intrinsic finite element (VFIFE) analysis is introduced to deal with numerical part containing a large number of DOFs, and a hybrid simulation framework is proposed for relieving the computation burden and realizing the real-time control based on VFIFE and the field programmable gate array (FPGA).