Vibration Reliability Analysis Of High Speed Underwater Vehicle Structure

The motion situation of Underwater High Speed Vehicle is very complicated, which suffers from all kinds of dynamic load's effects. The dynamic load's effects can increase the deformation and pressure of structure, make the vehicle structure bring resonance and structure failure, affect the normal operation of inner instruments. The vehicle's unstable phenomenon was not explained completely, if static load is analyzed merely and dynamic load is neglected. So it is practical significance under the dynamic load's effects for vehicle's structure vibration analysis and reliability study. The main contents of this paper are as follows:1,Basic theory of supercavity and structural reliability was studied and supercavity's morphology calculation model was analyzed. Cavitation device lift force, cavitation device resistance force, planing force, vehicle's thrust, gravity, friction resistance and their moments were analyzed and finished, then the dynamic model of supercavity vehicle was established.2,According to the hamilton principle, force of vehicle structure was analyzed under axial direction dynamic load's effects in the initial section. Structure's motion equation was solved and the characteristic curves of velocity and resistance force were educed. Dynamic analysis for vehicle was done by ANSYS software natural frequency and vibration model of structure was obtained. The maximum displacement and equivalent stress value was obtained, which was under the different exciting frequency effect. Moreover the axial displacement of cone shell's front, cone column combination department, column shell was obtained. Force of vehicle structure was analyzed in the tail beat section, and the regional under the impact load effect was determined. At the same time, vehicle's acceleration response in x, y, z directions was found out under the impact load effect.3,Reliability calculation was done, which was for the structure reliability of one supercavity vehicle model. According to the simulation results and experience, solved the reliability index of structural vibration under axial direction dynamic load's effects in the initial section and the impact load effect in the tail beat section, educed the influence of structure parameters for maximum displacement and equivalent stress.