Design Of Composite Pressure Vessels Research Articles

Failure prediction and optimization for composite pressure vessel combining FEM simulation and machine learning approach

Failure assessment is one of the fundamental tasks for optimization of composite pressure vessels (CPVs). However, the extensive design space of composites usually leads to costly and repetitive work of failure assessment that hinders the design and optimization of CPVs. In this work, a combined FEM simulation and machine learning approach is used to predict the failure factors R of CPVs for further optimization. CPVs with various design parameters are automatically generated and analyzed in ABAQUS to obtain failure factors under various external loadings. Then, an assembled deep neural network (DNN) namely Multi-DNN is trained to map relations between design parameters and R of CPVs. Further, transfer learning (TL) is introduced to improve the extensibility of our approach by fine-tuning the pre-trained Multi-DNN using scarce data of new design space. Such a TL-Multi-DNN model can precisely predict R of CPVs with new design parameters. Additionally, combining the trained models and genetic algorithm, the optimization of CPVs is carried out with high efficiency and low computational cost. As a result, R of CPV with various given and new design parameters can be estimated directly by the trained models and the optimal layer sequence of CPV can be obtained efficiently.

Bending theory of composite pressure vessels: A closed-form analytical approach

Composite pressure vessels are strategic for the present and future of the aerospace, transportation, and energy industries. These shell structures are utilized to store and transport liquids and gases and are principally composed of a cylindrical shell and two elliptical heads. The current rules for the structural design of composite pressure vessels make use of the membrane theory that excludes the bending of the structure. Nevertheless, the cylindrical shell and the elliptical heads present different curvature radii. These changes generate a localized bending deformation that determines an increase in the stress state as an effect of a local bending moment and shear force distributions that arise in the geometric transition zone. The stresses related to the bending effects die out rapidly, moving away from the junction plane, but they are sensibly higher than the membrane stress and, therefore, cannot be neglected in the mechanical assessment. Here, a closed-form analytical solution for the bending theory of composite shells is proposed. It can assist in the design of composite pressure vessels and drive the design towards reliable configurations for structural integrity. Using the Donnell–Mustari–Vlasov theory for thin-walled composite shells, the governing fourth-order differential equation is deduced and solved to obtain the displacements and stresses acting in the junction. The analytical results are successfully compared with those of reference finite element models for validation; their accuracy is proved considering different thicknesses, lay-ups, and flattening factors of the vessel

Design and manufacture of a Type V composite pressure vessel using automated fibre placement

Automated fibre placement (AFP) can improve composite pressure vessel design by enabling selective reinforcement and allowing a wider range of fibre orientations than the traditional filament winding process. This paper presents the development of an AFP Type V composite pressure vessel with a design working pressure of 4.22 MPa made using a novel collapsible mandrel. The design process is presented along with a thickness control strategy for the AFP parts using ply drops. The tank was manufactured, and the thickness was validated using 3D scanning. The masses of the AFP parts were also measured to within 2.23% of the predicted values. The finished tank was hydrostatically pressure tested to understand the leakage behaviour. Defects and difficulties encountered in this prototype are discussed and opportunities for future work and improvements have been identified.

Development of Abaqus WCM plugin for progressive failure analysis of type IV composite pressure vessels based on Puck failure criterion

The type IV composite pressure vessels (CPVs) are used as a reliable solution for storing compressed gas but still require research and development to reach commercial advancements. The main two challenges in the design of CPVs are: a) debonding of liner and composite shell during the curing process, and b) accurate finite element modeling of the thickness and angle variation of helical layers at the dome regions. In this study, debonding of composite shell from polymeric liner and bosses due to the temperature variations during the curing process is simulated by using bilinear cohesive law. Regarding the second challenge, the Abaqus WCM plugin is used to model the actual geometry of two-liter type IV CPV’s domes by defining and controlling manufacturing parameters. The UVARM subroutine is developed to apply stress analysis and predict the damage initiation using the Maximum Stress, Tsai-Wu, Tsai-Hill, Hashin, and Puck failure criteria. Also, a USDFLD subroutine is written to implement progressive failure analysis using the Puck failure criterion with sudden material degradation model. The numerical axial and radial displacements as well as burst pressure results are compared with the experimental results available in the literature. A good correlation is observed between the finite element and experimental results. Also, numerical results showed that the initial debonding gap due to curing does not affect the progressive damage of the composite shell.

Analytical modeling and numerical analysis of the effect of mosaic patterns on composite pressure vessels with dome

The aim of this work is to provide an analytical tool and numerical analysis for the optimum design of composite pressure vessels with the dome, incorporating triangular mosaic patterns. This article presents the analytical modeling involving kinematic constraints based on geodesic trajectory: the helical angle and dome thickness. The structural analysis is performed using a commercial finite element analysis tool. The results show that this new analytical method gives more accurate dome thickness than cubic spline function and Gramoll and Namiki’s methods. The incorporation of mosaic patterns based on winding kinematics provides more realistic modeling of the real stress distribution and the stress values compared to the vessel without mosaic patterns and vessels with mosaic patterns based on nongeodesic trajectories. The results have been validated and are quite promising with regard to better accuracy and safety.

On analytical and numerical solutions of inverse problems of the mechanics of composites

A number of statements of inverse problems of rational and optimal design of composite structures are considered. The problem of maintenance of a momentless state of a composite shell with respect to parameters’ choice of reinforcement is solved. The problem of optimum design of composite pressure vessels is investigated.

Design and Analysis of Hydrogen Storage Tank with Different Materials by Ansys

Pressure vessels are used for large commercial and industrial applications such as softening, filtration and storage. It is expected that high-pressure hydrogen storage vessels will be widely used in hydrogen-fuelled vehicles. Progressive failure properties, the burst pressure and fatigue life should be taken into account in the design of composite pressure vessels. In this work, the model and analysis of hydrogen storage vessels along with complete structural and thermal analysis. Liquid hydrogen is seen as an outstanding candidate for the fuel of high altitude, long-endurance unmanned aircraft. The design of lightweight and super-insulated storage tanks for cryogenic liquid hydrogen is since long identified as crucial to enable the adoption of the liquid hydrogen. The basic structural design of the airborne cryogenic liquid hydrogen tank was completed in this paper. The problem of excessive heat leakage of the traditional support structure was solved by designing and using a new insulating support structure. The thermal performance of the designed tank was evaluated. The structure of the tank was analyzed by the combination of the film container theory and finite element numerical simulation method. The structure of the adiabatic support was analyzed by using the Hertz contact theory and numerical simulation method. A simple and effective structure analysis method for a similar container structure and point-contact support structure was provided. Bases for further structural optimization design of hydrogen tank will be provided also. The analysis will be carried out with different materials like titanium, nickel alloy and some coated powders like alumina, Titania and zirconium oxide. The results will be compared with that.

A hierarchy of models for the design of composite pressure vessels

The mechanical response of pressure vessels to an applied internal pressure is essentially controlled by a few key parameters, related both to the overall geometry of the structure and to the orientations and thicknesses of the composite layers. The role of each parameter, and the way they interact to determine the structural response, can be apprehended at a very early design stage by using simple material and structural models, which enable to explore a wide range of designs with minimal computational cost. More complex models can then be called into play to predict the detailed structural response, including crucial information such as the burst pressure and failure mode. This paper discusses a hierarchy of models with increasing levels of details and complexity, which are useful to gain increasing insight on the pressure vessel response all along the design process.

A new concept for a modular composite pressure vessel design

A new concept for modular composite pressure vessels was developed countering the disadvantages of the common monolithic design. The modular concept consists of a fiber reinforced thermoplastic cylinder and separately manufactured vessel heads which have to be joined adequately. The design choices and advantages of this concept are presented. The relevant design parameters of the vessel head, a thermoplastic composite shell, will be discussed based on a numerical parametric study carried out in a commercial finite element code. From this study design recommendation will be derived. Furthermore, the manufacturing concept of the vessel head will be described and first produced parts will be presented.

Flaw Testing of Fiber Reinforced Composite Pressure Vessels

The ASME Boiler Pressure Vessel Project Team on Hydrogen Tanks, in conjunction with other ASME Codes and Standards groups, is developing Code Cases and revisions to the Boiler and Pressure Vessel Code, including such to address the design of composite pressure vessels. The Project Team had an interest in further understanding the effect of cuts to the surface of composite tanks, and how the burst pressure would be affected during the lifetime of the pressure vessel. A test program was initiated to provide data on initial burst pressure, and burst pressure after pressure cycling, of composite cylinders with cuts of different depth. This test program was conducted by Lincoln Composites under contract to ASME Standards Technology LLC, and was funded by National Renewable Energy Laboratory (NREL) [1]. These results were considered during the development and approval of the ASME Code Cases and Code Rules. Thirteen pressure vessels with a design pressure of 24.8 MPa (3600 psi), approximately 0.406 m (16.0 in.) in diameter and 1.02 m (40.2 in.) long, were tested to investigate the effects of cuts to the structural laminate of a composite overwrapped pressure vessel with respect to cycling and burst pressure. Two flaws, one longitudinal and one circumferential, were machined into the structural composite. The flaws were 57 mm long by 1 mm wide (2.25 in. × 0.04 in.) and varied in depth from 10% to 40% of the structural composite thickness of 11.4 mm (0.45 in.). These pressure vessels were cycled to design pressure 0, 10,000, and 20,000 times then burst. The resulting burst pressures were evaluated against the performance of a pressure vessel without flaws or cycling. The burst pressures were affected by depth of cut, but the pressure cycling did not have a significant effect on the burst pressure.

Multicriteria design of composite pressure vessels

Design of composite pressure vessels is characterised by multiple contradictory performance criteria, such as winding on the heads, dimension, volume, and weight. Statement and solution of such problems requires search for compromise solutions and consideration of multiple criteria simultaneously. Therefore, single-criterion approaches are generally not applicable. The paper presents a multicriteria methodology for search for feasible and Pareto optimal solutions for the design of composite pressure vessels. The methodology is based on the parameter space investigation (PSI) method. The PSI method is implemented in the multicriteria optimisation and vector identification (MOVI) software system. Using the above tools, this work provides a numerical example of statement and solution of the problem of multicriteria design of composite pressure vessels.

Application of surrogate based particle swarm optimization to the reliability-based robust design of composite pressure vessels

A surrogate based particle swarm optimization (SBPSO) algorithm which combines the surrogate modeling technique and particle swarm optimization is applied to the reliability-based robust design (RBRD) of composite pressure vessels. The algorithm and efficiency of SBPSO are displayed through numerical examples. A model for filament-wound composite pressure vessels with metallic liner is then studied by netting analysis and its responses are analyzed by using Finite element method (performed by software ANSYS). An optimization problem for maximizing the performance factor is formulated by choosing the winding orientation of the helical plies in the cylindrical portion, the thickness of metal liner and the drop off region size as the design variables. Strength constraints for composite layers and the metal liner are constructed by using Tsai-Wu failure criterion and Mises failure criterion respectively. Numerical examples show that the method proposed can effectively solve the RBRD problem, and the optimal results of the proposed model can satisfy certain reliability requirement and have the robustness to the fluctuation of design variables.

Design Improvement of Composite Pressure Vessel Structure

This paper presents a proposed approach for improving the design of a composite pressure vessel (CPV) under internal pressure. Thin shell theory, membrane theory, classical lamination theory and Tsai–Wu failure criterion are carefully integrated into an efficient mathematical model. The mathematical model is successfully combined with an in-housedeveloped algorithm that is used to improve the design of any given CPV. Case results show that the proposed approach successfully improved the design of a composite pressure vessel relative to the base design made from steel and also relative to a conventional CPV design approach.

Risk analysis of CNG composite pressure vessel via computer-aided method and fractography

As environmental issues threaten the widespread use of fossil fuels, Compressed Natural Gas (CNG) vehicles are explored as an alternative to the conventional gasoline powered vehicles. CNG vehicles have to be equipped with safe and reliable storage tanks, such as composite pressure vessels, since the failure of the CNG storage tank can lead to passenger fatalities and injuries. The most probable causes of failure of the CNG vehicles are fire and vessel fracture. In this research, the cause of vessel failure is investigated through formal inspection and engineering test procedures. Specifically, the failure mechanism will be identified by fractography, and the material properties of a reference part will be investigated through the instrumented indentation technique. Moreover, the composite pressure vessel design will be validated using the finite element method.

Study on the Structural Safety Evaluation for Pressure Vessel of the CNG Vehicle Using F.E.M.

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.

Evaluation of fiber material properties in filament-wound composite pressure vessels

Fiber material properties are the most important factors from among various material properties for the design of composite pressure vessels because of their dominant effect on the performance of composite pressure vessels. However, the fiber material properties of filament-wound pressure vessels are very sensitive to various processing variables and the size effect so that it is not possible accurately to measure fiber material properties using existing test methods. The hydro-burst test with full-scale pressure vessels is the best method to obtain fiber material properties, but it entails exorbitant costs. Consequently, the present paper proposes the hoop ring test, a newly developed test that is capable of pressure testing with ring specimens extracted from full-scale composite pressure vessels. The fiber material properties from the hoop ring test method showed good agreement with the results of the hydro-burst test with full-scale composite pressure vessels.

Composite Material Application and Development in Pressure Vessels

Some characteristics and advantages of composite material pressure vessels are discussed and main applications of composite material pressure vessels are expounded and development trend of composite material pressure vessels is pointed out in the paper. The paper has some reference values for research and design of composite pressure vessels.

Design of Composite Pressure Vessels with Metallic and Plastic Liners

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.

A Nonlocal Damage Theory for Laminated Plate with Application to Aircraft Damage Tolerance

Composite pressure vessel design requires the prediction of failure given large-scale damage. Cracks in composite laminates are known to develop a damage zone that exhibits strain-softening. This investigation sought to develop a computational model that simulates progressive damage and predicts failure of complex laminated shell structures subject to combined tension and flexure. The model assumed a macroscopic definition of orthotropic damage that was allowed to vary linearly through the shell thickness. It was further proposed that nonlocal plate strain and curvature act to force damage growth according to a set of uniaxial criteria. Damage induced strain softening is exhibited by degradation of laminate stiffness. An expression for the damage reduced laminated plate stiffness was derived which assumed the familiar laminated plate [ABD] stiffness matrix format. The model was implemented in a finite element shell program for simulation of fracture and evaluation of damage tolerance. A combined tension plus flexure fracture test was developed for characterizing damage. Analysis was performed on a section of pressurized composite fuselage containing a large crack. Good agreement was found between calculations and test results.

Application of Reliability and Fiber Probabilistic Strength Distribution Concepts to Composite Vessel Burst Strength Design

With the expanding use of composite vessels, including space and tactical applications, accurate prediction of performance becomes increasingly important. A criti cal parameter in performance prediction is the burst strength as measured by the delivered fiber ultimate strain-to-failure. This paper discusses a composite pressure vessel design approach that is based on reliability and probabilistic fiber strength distribution concepts.1 The method is based on the fiber strain-strength interference reliability theory. A substan tial part of this paper examines how fiber strength distribution parameters generated by tow tensile tests of impregnated carbon fiber strands can be used in pressure vessel strength design. The fiber statistical strength distribution is analyzed using the Weibull distribution function. It is shown that the bimodal Weibull distribution function fits the impregnated fiber strand strength distribution data much better than the single mode Weibull function. This is particularly important because the bimodal function gave a much more accurate representation of the lower tail of this distribution. According to the strain- strength interference theory, the lower tail of the fiber strength distribution is the most sig nificant in pressure vessel strength reliability calculations. The impregnated fiber strand strength distribution agrees well with the strength distribu tion of 4-in. biaxial composite tubes manufactured from the same carbon fiber lot. Good agreement was also shown with the strength distribution of pooled fiber lot tow tensile data and hydroburst strength distribution of full-scale composite pressure vessel manufactured from these lots. In this comparison, the A-basis fiber strength allowable calculated from the strand data was slightly lower (3%) than those calculated from the full-scale pressure vessel strength data, whereas, the B-basis allowables calculated from the strand and the full-scale pressure vessel strength data were the same. However, because A-basis and/or B-basis allowables require many data points from many material lots, the use of fiber lot qualification data is advantageous because it meets these requirements.