Thermo-mechanical Analysis For Composite Over-wrapped Pressure Vessel During Fast Filling Process

Composite materials which have widely been used in aerospace, automotive industry, medicine and chemical industry have the advantage of high specific strength, high specific modulus and thermal stability. The composite over-wrapped pressure vessel (COPV) incorporates the features of light weight, high strength, safety and reliability.The drivability, changing the direction and precise positioning of the aerospace vehicle and the satellite in space are always been implemented through the jet of COPV. But in the process of loading and unloading, the performance of COPV will change a lot because of the effect of temperature, pressure and the velocity of gas’ charging and discharging. In order to make sure the structural stability of COPV. this paper carries out analysis and research about the performance of COPV in the process of loading and unloading.First this paper outlines the present situation of development about the design of composite over-wrapped vessel and the coupled thermo-mechanical analysis at home and abroad. Then it introduces the basic theory and analysis of carrying out the subject study, including turbulence model equations, state equation of the transient heat conduction equations, structured analysis controlling equations and the expression of the corresponding finite element analysis. At the same time, this paper shows the strategy of multi-field coupling analysis, including the flow field, the temperature field, the pressure field and the stress field. On the basis of it. the author models the composite over-wrapped vessel successfully with the function of APDL in the large-scale programming system ANSYS and obtains the stress field, the temperature field, the air-charging velocity field, the displacement field and the cloud picture of stress and strain of the aluminum liner and the composite material layer through calculating with an example of the structure of a typical vessel. The result shows that:firstly, in the process of loading, changes of the temperature and the pressure field of the vessel do not exceed the scope of normal use; secondly, stress and strain of the composite over-wrapped layers and the aluminum liner in all parts of the vessel are both less than the limit stress and strain, which shows that the structure of the vessel is not been damaged in the process of loading and can still been used normally.