Reliability Of Ultimate Strength Of Disk Type Underwater Glider Under Random Corrosion

the Disk Type Underwater Glider is a new concept design in the form of underwater glider,adopted around the center axis of the fuselage structure of symmetry,the difference design,is the ability of the steering,no longer need to make a long distance glider rotary motion,as long as the tuning section within the slider move to function can be realized,maneuverability more excellent than conventional torpedo type underwater glider,suitable for running in the small domain.The research object of this paper is the disc-shaped underwater glider prototype designed and developed by the research group.We are concerned about the structural safety of the disc glider under the condition of severe corrosion in the long term seawater working environment.Firstly,as an important part of the glider structure,the pressure housing not on,ly provides the necessary buoyancy for the glider,but also plays the role of protecting internal instruments and electronic components,thus providing sufficient safety for the pressure housing.In the future work,the structure will be corroded by seawater for a long time,and the joints will suffer uncertain random damage.Whether the overall structure can still meet the safety strength requirements after such damage is the focus of this work.This article is based on the underwater glider in the midst of the sea to keep the suspended state general condition,to simplify the ultimate strength of the glider to external pressure hull in the water of the compressive ability,and in the structure calculation software for 3D simulation modeling,computational structure ultimate strength considering the material non-linearity,nonlinear,unconstrained condition such as free body.According to the corrosion experiment of submarine pipeline of the same material and the existing corrosion model fitting formula,the corresponding corrosion model was established,which was used to simulate the corrosion of a circular glider,and the nonlinear limit strength was calculated under certain corrosion years.Then on the basis of Monte Carlo Method,through a large number of random sampling in line with the corrosion under the model of the distribution of each term of a large number of corrosion data,calculate each of nonlinear ultimate strength on the structure of the mean,standard deviation,in order to calculate the time-variant reliability of structure,and calculation and analysis on the different corrosion model,working pressure,corrosion under the fixed number of year,the changing rule of the time-varying reliability,the working mode of the glider,life form and design improvement opinions are put forward.