Measurement And Analysis Of Underwater Shock Wave Based On Hopkinson Bar Technology

The experiment and measurement technology of underwater shock wave has always been one of the key points restricting the study of the dynamic response of underwater structures.Due to the rigorous requirements and poor repeatability of underwater shock wave experiments,traditional measurement methods are difficult to meet today's engineering requirements in terms of range and accuracy,and the waveform generated by the device relies too much on theoretical formulas.Based on Hopkinson rod technology,this paper improves the traditional nonexplosive underwater shock wave loading device.Combined with experiments and numerical simulations,the underwater shock wave generated by the device is carried out,and the propagation characteristics of the underwater shock wave are studied.The main research contents are as follows:1.The basic theory of underwater shock wave and the propagation theory of onedimensional stress wave propagation are described.The loading technology and principle of non-explosive underwater shock wave are introduced,and its advantages and disadvantages are analyzed compared with the medicine loading technology.2.Aiming at the shortage of non-explosive underwater shock wave loading technology,the Hopkinson rod principle was used to improve the shock wave loading technology.On the basis of the original experiment,an incident rod was added to obtain a more intuitive measurement of the loading waveform of the device on water,and the characteristics of underwater shock waves generated by the impact rod at different velocities were studied.3.Based on one-dimensional stress wave theory,a transmission rod measuring device for measuring underwater shock waves was designed using Hopkinson rod technology,and shock wave loading experiments were carried out to demonstrate the feasibility of a new type of underwater shock wave measurement technology.based on Hopkinson technology.Compared with the measurement results of piezoelectric sensors,the advantages of underwater shock wave measurement method based on Hopkinson bar technology are analyzed.4.Numerical calculations were performed using ABAQUS and AUTODYN finite element simulation software,and the results were compared with the experimental results of underwater shock waves.At the same time,by means of simulation,the factors such as length and thickness of the water tank,thickness of the back plate,length and speed of the impact rod,length and material parameter of the piston and incident rod,diameter and material parameter of the transmission rod,etc.,were analyzed for the effect on wave propagation measurement in the underwater shock wave loading device.The propagation characteristics of shock waves in fluids and the fluid-solid coupling interface are studied.