The Optimization Of The Autofrettage Pressure And The Fiber Thickness Of The Fully-wrapped Composite Gas Cylinder

As the widely application of the composite gas cylinder, the scientific analysis and precise calculation to the composite gas cylinder become more and more important. With ANSYS software and finite element method, a model of composite gas cylinder is presented in this paper. The element selection, the element density, the real constant and the boundary condition are also discussed and the APDL program is wrote. The stress distributions in each process of the manufacture, using, experiment and burst are obtained. And the fatigue failure position is discussed.By taking a 2L fully-wrapped composite gas cylinder as an example, the autofrettage pressure influences to the stress distribution is discussed. The stresses relative to different autofrettage pressure are obtained from ANSYS calculation. And it is shown that an autofrettage pressure can reduce the stress level on work pressure and can change the load distribution between the liner and the fiber layer on work pressure. In the end, the optimization of the autofrettage pressure is achieved.In addition, the hoop fiber thickness influences to the stress distribution is discussed, too. Changing the hoop fiber thickness with the liner and the longitude fiber fixed, different models with different hoop fiber thickness are obtained. Then the stresses are calculated. And the results shown that with the increase of the hoop fiber thickness, the autofrettage pressure must increase to get the same autofrettage effect, and that the stress of the liner and the fiber are reduced on both work pressure and minimum burst pressure. In the end, the optimization of the hoop fiber thickness is achieved.