Papers by Keyword: Composite Pressure Vessel

Abstract: The investigations deal with the experimental characterization of the structural deformation of type IV pressure vessels subjected to internal pressure. For the widespread use of hydrogen technology in transport industries, the development of cost-effective storage systems is a crucial step. State of the art in the field of hydrogen storage are type IV pressure vessels, which consist of a polymeric liner and an enforcing winding of carbon fiber-reinforced plastic (CFRP). For the development of material-optimized and high-safety pressure vessels, the acquisition of reliable experimental data in order to validate numerical simulations is a necessity. In a specially designed test chamber subscale vessels are clamped and subjected to internal pressure. At defined pressure stages the vessel’s deformation is recorded and analyzed. Consequently, the overall structural deformation is assessed with regard to the used structural mass, the burst pressure and the resulting failure. The results can be used for structure optimization purposes as well as for the optimization of numerical simulation models.

Abstract: In this present work, the composite pressure vessel type three has been investigated by finite element method (FEM). The aluminum pressure vessel reinforced with Kevlar/Epoxy (Aramid 149) was analyzed under internal pressure to predict the ultimate failure pressure of the vessel. Also the optimum winding angle which provides the highest strength for the vessel was determined by applying Tsai-Wu and Tsai-Hill failure theories. The asymmetric fiber orientation for six different winding angles was utilized to reinforce the aluminum vessel. The commercial code ABAQUS/CAE was employed to analyze the composite vessel. Results obtained from the simulation were in good consistency with the analytical and the experimental outcomes.

Abstract: In this paper we apply semi-geodesic trajectories to the creation of isotensoid domes for filament wound pressure vessels. The governing equations for the determination of the meridian shapes and related winding angle distributions of domes are derived using the netting analysis and the semi-geodesic winding law. The effects of the slippage coefficient on the geometry and fiber trajectories of the domes are respectively evaluated in terms of the resulting meridional curves and fiber angles. It is revealed that the semi-geodesic angles and the dome depth have an overall decrease with increasing the slippage coefficient. The results also demonstrate that the use of semi-geodesics significantly enlarge the design space for the geometry and adapted fiber trajectories of the domes. The present method can provide a significant reference for the design and production of the domes for semi-geodesically overwound pressure vessels.

Abstract: This paper describes a composite pressure vessel(COPV) development program which have been finished by Lanzhou Institute of Physics (LIP). In order to dramatically improve reliability and safety of COPV applied in military aircraft, this COPV(L376-COPV) design relies partly on the heritage of mature technologies and was developed in combination with existing and new technologies, Unlike traditional COPV, the impact resistant capability from high energy bullet of L376-COPV is improved greatly by liner material heart treatment and T800/K49 fiber hybrids over-wrap. L376-COPV design, analysis, manufacturing, testing and results was introduced.

Abstract: Load sharing metal lined composite pressure vessel(COPV) enables significant safety and reliability over those vessels with non-load-sharing metallic or non-metallic liners, The key technical challenge in developing these vessels will be to calculate the optimized liner thickness and liner elastic strain. This paper presents techniques developed at Lanzhou Institute of Physics(LIP) for the design of elastically operating metal liner COPV in terms of NET theory which modified by LIP. Five metal materials are discussed and analytical techniques for determining liner thickness are presented, selection of materials for maximizing performance and minimizing weight is discussed. L490A-COPV development is introduced, performance factor is improved from 23 Km to 29.5Km.

Abstract: CNG vehicles have to be equipped with a safe and reliable storage tank, such as composite pressure vessels, since the failure of the CNG storage tank induces fatal damages to passengers. In this research, the cause of vessel facture is investigated through formal inspection and engineering test procedures. Specifically, the composite pressure vessel design will be validated using the finite element method. In order to validate values of the optimal design variables in accordance with standard of the high pressure gas safety management, we used safety probability such as Von-Mises yield criterion, Tsai-Hill theory and stress ratio.

Abstract: The heat convection was the main heat exchange in the autoclave by which composite pressure vessel was cured. To determine the heat convection coefficient, the combination of theoretical calculation and temperature test is absolutely necessary. In the theoretical calculation, the determination of the heat convection coefficient is considered as an inversion problem of thermal conduction. By adjusting convection coefficient value in the finite element calculation, optimization method was employed to obtain a good agreement between calculated temperature and measured temperature. In the temperature test, the metallic liner of pressure vessel was used as test component to record temperature data which was compared with the calculated temperature. The results present the equivalent thermal boundary condition for the simulation of curing process of pressure vessel.

Abstract: The progressive failure analysis of composite pressure vessel under hydrostatic pressure has been carried out. The composite pressure vessel has been modeled by using layer structural shell element. After the failure of the weakest ply, the stiffness is reduced by either fiber failure or matrix failure. The stiffness of failed element has been totally discarded and other element are considered to remain unchanged after the weakest ply failure. The stress of the laminate at the same point is evaluated again to see if the laminate can carry additional load. This ply-by-ply analysis progresses until the ultimate strength of the pressure vessels is reached. A parametric study has been done on the progressive failure analysis.

Abstract: Lightweight composite pressure vessels were designed with thin metallic and plastic liners. This paper discusses the structural design, the fabrication, and the experiment of the composite pressure vessels with metallic and plastic liners. Both liners were non-load sharing types, therefore only the composite sustained an internal pressure. The liner provided a gas seal. The materials of the liners were Al 6061 and CLPE (cross linked polyethylene) each. The composite pressure vessels were winded using T700 carbon/epoxy on the liners. The multiple cure cycles prevented the aluminum liner from losing a circular shape and the concentrated force at the metallic boss was spread to the composite fiber by the boss design. In case of the plastic liner, the boss design considered that CLPE had no adhesive property. Although the plastic liner has the advantage for the elongation, some environmental tests for temperature and vibration effects are needed in order to use in space applications.