Study On Design Method Of Large Capacity Fully-wrapped Composite Cylinders

With the rapid development of economy in our country, long tube trailer asthe transportation of natural gas has been more and more widely used in manyfields such as industry, energy and logistics. The Fully-wrapped compositecylinder with its light weight and stable performance, is most probably toinstead of the large volume of steel cylinder composite cylinders in the future.On the basis of predecessors’ research, aiming at the problem of internalpressure burst failure, fatigue failure and torsional failure of Cylinders, throughthe finite element simulation, research, the theoretical research and experiment,the design method of fully-wrapped composite cylinder has been studied. Themain research work and conclusions of this paper are as follows:1.For bursting failure researching, consider the autofrettage process and usefinite element software ANSYS to establish calculation model of the largecapacity fully-winding composite cylinders. Use bursting failure as the onlyfailure mode can design a kind of simple optimization method which meets thedesign standard of using minimize fiber. With the optimization method, afully-wrapped composite cylinder with steel liner thickness of6.0±0.2mm isdesigned.2.To study on the internal pressure fatigue failure, the tank fatigue performance which the pre-tightening force and the layer number of twisting have effect on are simulated by finite element numerical ion and analysis.By research and welding residual stress test,the fatigue properties of the welded tank were analyzedthat it is difficult to meet the requirements which practical application of welding the tank of gas cylinders fatigue.Basing on the blasting Failure design method,the pressure of25MPa and30MPa pressure tank with559x7.9thin-walled ste el tube carbon fiber wrapped all the big volume of composite cylinders are designed,and it provide the basis for manufacturing and designing25MPa or30MPalarge volume of cylinder.3.Large capacity cylinders installed in the frames of tube trailers subject totorques caused by their own degree of curvature and out of roundness. An torquetesting device used in large capacity cylinders is established, and it can be usedto transform testing degree of curvature and out of roundness to testing torque.Testing platform was build, and5cylinders were tested. For quantitativeanalysis, an explicit calculation method was presented to predict the maximumtorques introduced by the degrees of curvatures and out of roundness of thecylinders under gravity, and allowable values of maximum torques arecalculated. Strength check was carried out on the pin and found that, for thecylinder which meet requirement of curvature degree and out of roundnessdegree, two pins can prevent the cylinder form rotating.