| Wave impact (slamming) is a strong impact collision phenomenon between wave and structure, which involves the complex interaction between solid, fluid and gas of the three-phase medium. Severe wave impact can lead to the partial damage or the entire collapse of structures. For elastic marine structures, there was a complex dynamic process due to the interaction between wave impact and vibration response of the structure. With the development of hydroelasticity in the coast and offshore engineering, which has urgent needed for carrying out a systematic deep research work to further study the mechanism of wave impact process, and has understood the variation characteristics of the dynamic response during wave slamming on structures.In this paper, the physical model test was carried out to investigate the variation characteristics of impact load and dynamic response during wave impact on the flat plate construction with elastic support. Experiments were performed in the wave flume of Dalian University of Technology, three kinds of structure models with different support stiffness were designed, and the dynamic characteristics of the models were obtained by static displacement method and transient excitation method in the experiments. The synchronous measurement data of impact pressure and vibration acceleration during wave slamming underneath the structure were gained by using the Crio-9074 multi-channel synchronous acquisition system.In this experiment, the wave impact pressure of the bottom surface of flat plate construction with elastic support was analyzed by using probability theory, the probability distribution curves of the wave impact pressure peak value and its expression were given, and the relationships between the incident wave parameters, dynamic characteristics of structure and the characteristic parameters of exceeding distribution curves were analyzed.The synchronous variation characteristics of wave impact process and flat plate motion process were given by means of the simultaneous analysis on wave impact force and vibration acceleration during wave slamming on the flat plate construction. Four characteristic stages in the synchronous time series of wave impact force and vibration acceleration were analyzed, namely:wave salmming stage, hydrodynamic interaction stage, fluid shedding stage and free vibration stage. The influence laws of elastic support stiffness, incident wave height, wave period and relative clearance on impact interaction duration were discussed.Based on the statistical analysis and spectral analysis results of wave impact loads, the distribution situation of wave impact pressure peak along the bottom surface of flat plate construction was given. The influence laws of elastic support stiffness, incident wave parameters and relative clearance on wave impact pressure (impact force) were analyzed. The influence of elastic support stiffness on the amplitude spectrum of wave impact loads was discussed. The conclusion of wave impact loads suffered by structure increase with the support stiffness increase was obtained.The frequency domain integral method was applied to the time series of acceleration, then the time series of flat plate construction vibration velocity and displacement were got, and the spectrum analysis on the dynamic response of the flat plate was carried out. The influencing factors of the dynamic response of structure are analyzed. The influence of elastic support stiffness on the amplitude spectrum of dynamic response was discussed. The conclusion of vibration acceleration of the structure increase and vibration velocity and displacement decrease with the support stiffness increase was obtained. |
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