• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.04a
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• pp.33-36
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• 2005

In this research, for the smart health monitoring of the hydrogen storage high pressure composite vessel, the feasibility study of an embedded fiber Bragg grating(FBG) sensor is carried out. To verify strain measurement in various temperature environment which is needed for the hydrogen pressure vessel, tensile test of a composite specimen with both an embedded FBG sensor and a strain gauge is made in low temperature. Before we try a real-size hydrogen storage pressure vessel, a small & cheap composite pressure vessel having the same structure is fabricated with embedded FBG sensors and tested. In the case of an aluminum liner inside the vessel, survivability of FBG sensors at the interface is lower than the other areas.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.10a
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• pp.10-14
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• 2002

Structural behavior of high-pressure composite vessels of TYPE 3 (full-wrapped over a seamless aluminum liner) was studied through numerical simulations based on 3D nonlinear finite element method. Under high-pressure loading, a TYPE 3 composite vessel shows material nonlinearity due to elastic-plastic deformation of aluminum liner, and mismatch of deformation at the junction of cylinder and dome causes geometrical nonlinearity. Finite element modeling and analysis technique considering this nonlinearity was presented, and a pressure vessel of 6.8L of internal volume was analyzed. Design specification to satisfy requirements was determined based on analysis results.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2001.05a
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• pp.197-200
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• 2001

A manufacturing process of composite pressure vessel was studied. The vessel was fabricated using the filament winding process. It is utilized as a container of high pressure Helium gas which propels a rocket fuel and an oxidizer. The layup patterns were determined based on the lamination theory. 3-axis controlled filament winding machine was developed to realize the patterns. The vessel was successfully fabricated using the developed machine. And the hydraulic pressure test was performed to measure an applied pressure-strain relations on the composite vessel.

• Journal of the Korean Society of Propulsion Engineers
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• v.1 no.2
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• pp.1-11
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• 1997

During hydroproof test of composite pressure vessel, acoustic emission signal was measured and analyzed to evaluate structural integrity of composite motor case. When pressure was held for 1 min. at constant pressure from low pressure level to high pressure level, the pattern of hit rate of good composite pressure vessel is increased with higher value than that of bad composite pressure vessel. This report also presents detection possibility of burst location approximately in the range of 25∼36％ of burst pressure using energy rate. In case that it is difficult to detect burst location of composite motor case, it is possible to detect burst location, i.e. structurally weak location of composite pressure vessel with applying same pressure lower than maximum expected operating pressure(MEOP) repeatedly.

• Journal of the Korean Society of Safety
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• v.34 no.5
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• pp.7-14
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• 2019

The type III vessel, which is used to store high-pressure hydrogen gas, is made by wrapping the vessel's liner with carbon fiber composite materials for strength performance and lightening. The liner seals the internal gas and the composite resists the internal pressure. The properties of the fiber composite material depends on the angle and thickness of the fiber. Thus, engineers should consider these various design variables. However, it significantly increases the design cost due to the trial and error under designing based on experience or experiments. And, for aluminum liners, fatigue loads due to using and charging could give a huge impact on the performance of the structure. However, fatigue failure does not necessarily occur in the position under the highest load in use. Therefore, for hydrogen storage vessel, fatigue evaluation according to design patterns is essential because stress distribution varies depend on composite layer patterns. This study performed an optimization analysis and evaluated a high-pressure hydrogen storage vessel to minimize these trial and error and improve the reliability of the structure, while simultaneously conducting fatigue assessment of all patterns derived from the optimization analysis process. The results of this study are thought to be useful in the strength improvement and life design of composite reinforced high-pressure storage vessels.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.6
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• pp.151-157
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• 2018

In this study, we have developed a composite pressure vessel that is compact and can store refrigerant at high pressure to increase the refrigerant volume. The composite pressure vessel is made of aluminum-based duralumin, which has high rigidity and excellent elongation in the inner liner, considering the characteristics of products in the aerospace and defense industry, where the safety of the applied product is considered as a priority. High strength carbon fiber was applied to the outside. In order to evaluate the performance of the developed product, burst test and cycling test were carried out. In burst test, an excellent safety margin equivalent to 2.7 times the operating pressure was obtained. In cycling test, a stable failure mode in which 'pre-burst leak' occurs is proved and the soundness of the product is proved.

• Composites Research
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• v.17 no.5
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• pp.1-6
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• 2004

Composite pressure vessels with HDPE (high density polyethlyne) liner with metal boss at each end were developed by Filament Winding Process. The vessel is composed of a dome-shaped part at each end and a cylinder-shaped part at the middle of the vessel. The environmental tests carried out for possible vessel materials such as High Density Polyethlyn (HDPE), resins and reinforcing fibers up to a year showed no significant damages. The boss was designed to minimize the gas leak which was verified by FEM analysis. Most ideal fiber tension was obtained by experimental method and the fiber volume fraction, $\textrm{V}_{f}$, obtained by image analyzer were 55.4 % in cylinder and 55.6 % in dome parts, respectively. Winding pattern is programmed to control the composite thickness in the dome areas such that the failure of the vessel may occur in the cylinder. During the cure, the vessel was rotated and a constant internal pressure of 0.62 bar was applied. From this, the vessel's burst pressure is improved by 28 %. The burst and fatigue tests for under-wound and fully wound vessel showed satisfactory results.

• Composites Research
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• v.35 no.6
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• pp.425-430
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• 2022

In this study, the mechanical properties of the pressure vessel composite exposed to the thermal environment were evaluated to establish the standard for high temperature static pressure test of the pressure vessel for hydrogen bus. As the tensile strength of the composite material approaches the glass transition temperature of the epoxy resin, the strength decreases due to the deterioration of the epoxy resin. In addition, it was confirmed that the tensile strength increased again due to the post-curing of the epoxy resin during long-term exposure. Therefore, the accelerated stress rupture test conditions of the pressure vessel for the hydrogen bus should be set based on the epoxy resin properties of the carbon fiber composite material.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.1
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• pp.205-213
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• 2003

The fiber reinforced composite material is widely used in the multi-industrial field where the weight reduction of the infrastructure is demanded because of their high specific modulus and specific strength. It has two main merits which are to cut down energy by reducing weight and to prevent explosive damage preceding to the sudden bursting which is generated by the pressure leakage condition. Therefore, Pressure vessels using this composite material in comparison with conventional metal vessels can be applied in the field such as defense industry, aerospace industry and rocket motor case where lightweight and the high pressure are demanded. In this paper, for nonlinear finite element analysis of E-glass/epoxy filament winding composite pressure vessel receiving an internal pressure, the standard interpretation model is developed by using the ANSYS, general commercial software, which is verified as the accuracy and useful characteristic of the solution based on Auto LISP and ANSYS APDL. Both the preprocessor for doing exclusive analysis of filament winding composite pressure vessel and postprocessor that simplifies result of analysis have been developed to help the design engineers.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.275-280
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• 2008

To improve the durability of a hydrogen pressure vessel which is applied high-pressure, it needs the autofrettage process which induces compressive residual stress in the Aluminum liner. This study presents the elasto-plastic analysis to predict the behavior of structure accurately, and the Tsai-Wu failure criterion is applied to predict failure of pressure vessel of Aluminum liner and composite materials. Generally, plastic analysis is more complex than elastic analysis and has much time to predict. To complement its weakness, the AxicomPro(EXCEL program), applied radial return algorithm and nonlinear classical laminate theory (CLT), is developed for predicting results with more simple and accurate than the existing finite element analysis programs.