Reliabilityanalysis About The Joint Of Cylinder Vessel And Spherical Head With High Pressure

The pressure vessel is mainly used in chemical industry in the early time, the pressure is always below 10MPa.When high-pressure production process as ammonia and high-pressure polyethylene appears, it requires the pressure of pressure vessels up to 100 MPa or more. With the developing of chemical and petrochemical industry,The operating temperature of pressure vessels became higher and higher, the capacity became bigger and bigger, even in some cases, it must be corrosion-resistant.From the 1960s,with the development of nuclear power,people put forword higher safety and technical requirements to reactor pressure vessel, it promotes the further development of pressure vessels,and it is widely used in various industrial sectors. April 26, 1986, the worst nuclear accident in the world occurred in the Soviet Union Chernobyl nuclear power plant. Now,the security of Pressure vessel has been paid more and more attention.In this paper, we take pressure vessel shell under 16 MPa as object of study, make use of the finite element analysis software ANSYS to simulate the experiment. First, we do deterministic finite element analysis for the model, As the structure is rotating body and its structural similarity, its simplified model is the upper part of the right end of two-dimensional model .We obtain the maximum stress distribution region and the maximum stress values in a given depressed through precise modelling and the grid division, and analyze the pressure distribution rule under determining pressure through the path of operation. Based on this we carry on the stochastic finite element analysis to the model, take the definition of reliability performance function as Z = yies-maxs, simulate the frequency of sampling with application of monte Radin hypercube method and calculate the reliability of the structure. It shows the convergence state of the whole process through process map of the sampling, and it also shows that the number of random operations is sufficient, the result is sufficiently reliable. Finally, we analyze the sensitivity of the biggest node equivalent stress maxs which is used to output variables and output performance functionZ in this examples, it offers a reliable theory in improvement of the pressure vessel design.