Filament-wound Composite Pressure Vessels Research Articles

Comparative Study on Multi-type Domes of Filament-Wound Composite Pressure Vessels

Filament-wound Composite Pressure Vessels (FCPV) have been used widely in the aerospace and commercial industries. Multi-type FCPVs have been applied to different mission scenes. In this paper, four types of domes (helical winding, helical winding ellipsoid, polar winding, polar winding ellipsoid) are studied based on a simplified parametric model, and a modified meridian computing method is employed for polar and helical winding domes after the inflection points. At last, four FCPV cases of different type of domes are calculated and discussed in detail. Results indicate that the parameters of the same winding pattern dome are similar, so it is suggested to use ellipsoid domes in prior for the convenience of fabrication and avoiding the inflection point at the meridian.

Experimental and numerical investigation of the strain response of the filament wound pressure vessels subjected to pressurization test

AbstractThis article presents the strain response of glass fiber reinforced epoxy matrix pressure vessels subjected to pressurization test. Three filament wound composite pressure vessels with different dimensions are manufactured by fiber winding processing, and the pressurization tests of these pressure vessels are performed. The stain of the inner/outer surface of the vessels during the pressurization tests is recorded. A progressive damage model is built based on the 3D Hashin failure criteria by finite element method (FEM) to predict the strain response of the composite pressure vessels. Fundamental mechanical tests that including the tensile, double cantilever beam, and three‐point end notched flexure tests of the composite laminates are carried out to determine the strength and stiffness parameters used in the FEM. The results show that the circumferential strain of the three composite pressure vessels is greater than the longitudinal strain. The maximum stress and strain occurs at the head of the pressure vessels. The predictions of FEM match the experimental results well, and the strain differences between FEM and experiments of the pressure vessels are less than 12%.

In-Situ Monitoring of a Filament Wound Pressure Vessel by the MWCNT Sensor under Hydraulic Fatigue Cycling and Pressurization

As a result of the high specific strength/stiffness to mass ratio, filament wound composite pressure vessels are extensively used to contain gas or fluid under pressure. The ability to in-situ monitor the composite pressure vessels for possible damage is important for high-pressure medium storage industries. This paper describes an in-situ monitoring method to permanently monitor composite pressure vessels for their structural integrity. The sensor is made of a multi-walled carbon nanotube (MWCNT) that can be embedded in the composite skin of the pressure vessels. The sensing ability of the sensor is firstly evaluated in various mechanical tests, and in-situ monitoring experiments of a full-scale composite pressure vessel during hydraulic fatigue cycling and pressurization are performed. The monitoring results of the MWCNT sensor are compared with the strains measured by the strain gauges. The results show that the measured signal by the developed sensor matches the mechanical behavior of the composite laminates under various load conditions. In the hydraulic fatigue test, the relationship between the resistance and the strain is built, and could be used to quantitative monitor the filament wound pressure vessel. The bursting of the pressure vessel can be detected by the sharp increase of the MWCNT sensor resistance. Embedding the MWCNT sensor into the composite pressure vessel is successfully demonstrated as a promising method for structural health monitoring.

Design of filament-wound spherical pressure vessels based on non-geodesic trajectories

One of the most key issues for design and production of composite spherical pressure vessels reflects on determination of the stress distributions and burst failure load of the vessels. The main objective of this study is to carry out the investigation of the stress/strain distributions and the ultimate strength analysis for filament-wound composite spherical pressure vessels based on non-geodesic winding trajectories. The non-geodesic patterns were simulated to determine the appropriate tangent points. The dome thickness distributions were precisely predicted using the cubic-spline function. The finite element model of the spherical vessel was created using the discrete method. The optimal autofrettage pressure was calculated to improve the bearing capacity of the autofrettaged vessel. The strain distributions of the composite layers at various selected locations were obtained numerically and experimentally, respectively. The burst pressure was deterministically predicted with the aid of the maximum strain criterion and was validated using the obtained experimental data. It is shown that the experimental results are in good agreements with those determined using the finite element model, which demonstrates that the present method is able to provide valuable reference for design of filament-wound spherical pressure vessels.

Structural Integrity Assessment of Filament Wound Composite Pressure Vessel Using Through Transmission Technique

Filament wound composite pressure vessels are widely used as rocket motor case for space applications due to its high performance factor. High performance factor is attributed due to the fact that composite materials are having higher specific strength, high specific modulus and strength tailorability characteristics which results in reduction of weight of the structure. However composite structures are more prone to damage accumulation such as matrix cracking, delamination, de-bonding, porosity, fibre buckling, fiber breakage etc. which are encountered in entire manufacturing cycle. Timely and accurate detection of above damage throughout its service life is necessary to have a reliable structure. Here, a through transmission ultrasonic testing methodology has been established for detection of defect in large sized composite pressure vessel. In the last decade, many open literatures have been available on design, development and qualification of composite pressure vessels, however no comprehensive work is available on structural integrity assessment using above said technique. This paper discusses on insight of various defect arised due to process parameter variation during manufacturing and its detection using through transmission ultrasonic technique. Further challenges multifold due to lack of full proof methodology and reference standards in open source. Hence customized reference blocks have been made simulating defect such as delamination & simulating varying thickness and their ultrasonic responses have been characterized. Ultrasonic response on full scale composite pressure vessel was studied and finally an overview of structural integrity assessment of composite pressure vessel has been presented.

Embedded optical fibres for monitoring pressurization and impact of filament wound cylinders

Filament wound composite pressure vessels have found use throughout many industries for storing high-pressure gases. The ability to investigate the vessels for possible damage from accidental impact loads is important for applications in the transport sector. Standard non-destructive methods are complicated. This paper describes a method to permanently monitor pressure vessels for their structural integrity.The method is based on standard telecommunications grade optical fibres embedded in the composite overwrap as a network of distributed strain sensors. Challenges regarding the practical implementation of optical fibres, and post-processing of signals, are discussed. During pressurization, the optical fibres were used to measure strains in several thicknesses of the composite layup. The cylinders were impacted and the backscattered light from optical fibres was then analysed to visualize the position and the severity of damage. The interrogation of embedded optical fibre networks is successfully demonstrated as a promising method for structural health monitoring of composite pressure vessels.

Design and analysis of filament-wound composite pressure vessels based on non-geodesic winding

In this paper a novel design approach was proposed for determining the optimal winding parameters of composite pressure vessels based on non-geodesic trajectories. With the aid of the differential theory and winding principles, the non-geodesic trajectories were derived for various tangent points. The obtained non-geodesics for composite pressure vessels were simulated using MATLAB to verify the validity of the trajectory design. The influence of the number of the tangent points and the roving bandwidth on the non-geodesic winding patterns was evaluated. The optimal number of the tangent points and the roving bandwidth were then determined while ensuring fiber stability and full coverage on the mandrel. The finite element model of the pressure vessel was established, taken variable ply thicknesses and angles along the dome meridian into account. In addition, the stress distributions of the aluminum liner and the composite overwrap were obtained and the burst pressure of the pressure vessel was predicted. The specimen of a composite pressure vessel was fabricated using the filament winder and the experimental results were consistent with the theoretically predicted ones. It is concluded that the present method is of great significance for design and manufacture of composite pressure vessels.

Dome shape optimization of filament-wound composite pressure vessels based on hyperelliptic functions considering both geodesic and non-geodesic winding patterns

Filament-wound composite pressure vessels, owing to the advantages of their high specific strength, specific modulus and fatigue resistance, as well as excellent design performance, have been widely used in energy engineering, chemical industry and other fields. A filament-wound composite pressure vessel generally consists of two parts, a cylindrical drum part and the dome parts. In the cylindrical drum part, the filament winding angle and the winding layer thickness can be easily determined due to the regular shape. In the dome parts, however, both the winding angle and the thickness vary along the meridian line. Performance of the dome parts, which strongly depends on the effect of end-opening and the winding mode, dominates the performance of a pressure vessel. In this paper, optimum design of the dome parts is studied by considering both geodesic winding and non-geodesic winding patterns. A hyperelliptic function is adopted as the basis function for describing the meridian of the dome shape. The dome contour is optimized by taking the shape factor (S.F.) as the objective and parameters in the basis function as the design variables. A specific composite pressure vessel is taken as the numerical analysis example with varying dome shape which is to be optimized. The optimum design solution is obtained through the particle swarm optimization algorithm. It shows that an optimized dome with non-geodesic winding has better S.F. as compared with geodesic winding. Influences of the slippage coefficient and the polar opening on the S.F. are also discussed.

Filament Wound Composite Pressure Vessels and Pipes Subject to an Internal Pressure: An Experimental and Material Characterization Study

This study presents an experimental testing regime conducted on filament wound composite pressure vessels (CPVs) made up of an asymmetric and unbalanced layup (chopped strand mat (CSM)/−82.7 deg/±54.3 deg) and subject to an internal pressure. Polyester reinforced with e-glass CSM and direct roving was used. The mechanical properties of the different lamina used in the test specimens were identified through a series of standardized tests. The evolution of strain and volume changes with respect to the applied pressure loading were recorded. The results also present a characterization of identifiable first-ply failure (FPF) loads based on strain evolution and volume changes, and monitors when ultimate failure occurs.

Optimum head design of filament wound composite pressure vessels using a hybrid model of FE analysis and inertia weight PSO algorithm

Filament wound composite pressure vessels are widely used in industrial applications. Determination of the optimal head profile has been recognized as one of the most important design issues. This paper presents the optimum design of head contours for a filament wound composite pressure vessel using a hybrid model of finite element analysis and inertia weight particle swarm algorithm. Geometrical limitations, winding conditions and the Tsai-Wu failure criterion have been used as optimization constraints. The objective is to maximize the shape factor using present optimization technique. An actual design example taken from available literature is used as a case study. Results indicate that the dome contours using the suggested method shows stronger structure and greater internal volume. This confirms that the proposed model can efficiently define the optimal dome shape.

Numerical/experimental impact events on filament wound composite pressure vessel

Impacts on pressure vessels, produced by winding glass fibre with vinyl ester resin over a polyethylene liner, were numerically and experimentally investigated in the current work.Pressure vessels were experimentally tested under low velocity impact loads. Different locations and incident energies were tested in order to evaluate the induced damage and the capability of the developed numerical model.An advanced 3-D FE model was used for simulating the impact events. It is based on the combined use of interlaminar and intralaminar damage models. Puck and Hashin failure theories were used to evaluate the intralaminar damages (matrix cracking and fibre failure). Cohesive zone theory, by mean of cohesive elements, was used for modelling delamination onset and propagation.The experimental impact curves were accurately predicted by the numerical model for the different impact locations and energies. The overall damages, both intralaminar and interlaminar, were instead slightly over predicted for all the configurations.The model capabilities to simulate the low velocity impact events on the full scale composite structures were proved.

Buckling Behaviour of Circular Ring Stiffened Filament Wound Composite Pressure Hull through Finite Element Analysis

The aim of present study was investigate the buckling pressure of moderately thick-walled filament-wound carbon–epoxy stiffened composite pressure vessel subjected to external hydrostatic pressure through finite element analysis and compare the result with un-stiffened filament wound carbon/epoxy composite pressure vessel used in under water vehicle applications. The winding angles were [±30/90] FW, [±45/90] FW and [±60/90] FW. ANSYS 14.0 APDL, a commercial finite element software package successfully predicted the buckling pressure of filament-wound composite pressure vessel with a deviation much higher than the results of un-stiffened filament wound composite cylinder .All the finite element analysis shows that the composite pressure vessel with winding pattern [±60/90] FW has the higher value of critical buckling pressure. Major failure modes in both the analysis were dominated by the helical winding angles.

Finite element analysis of filament-wound composite pressure vessel under internal pressure

In this study, finite element analysis (FEA) of composite overwrapped pressure vessel (COPV), using commercial software ABAQUS 6.12 was performed. The study deals with the simulation of aluminum pressure vessel overwrapping by Carbon/Epoxy fiber reinforced polymer (CFRP). Finite element method (FEM) was utilized to investigate the effects of winding angle on filament-wound pressure vessel. Burst pressure, maximum shell displacement and the optimum winding angle of the composite vessel under pure internal pressure were determined. The Laminae were oriented asymmetrically for [00,00]s, [150,-150]s, [300,-300]s, [450,-450]s, [550,-550]s, [600,-600]s, [750,-750]s, [900,-900]s orientations. An exact elastic solution along with the Tsai-Wu, Tsai-Hill and maximum stress failure criteria were employed for analyzing data. Investigations exposed that the optimum winding angle happens at 550 winding angle. Results were compared with the experimental ones and there was a good agreement between them.

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.

Research on Homogenization of Composite Materials

A numerical model is given to identify equivalent parameters of composite materials, using BP neural network algorithm. Taking Filament-wound composite pressure vessels as the research object, finite element models are first constructed .Getting node displacements as network training samples, the mechanical parameters as output information of network for effective training, the equivalent material parameters can be obtained. The satisfactory numerical validation is given and results show that the proposed method can identify the equivalent modulus and the equivalent Poisson’s ratio of the Filament-wound composite pressure vessels with precision. The computational efficiency is improved with BP neural network.

Design and Qualification of a Advanced Hybrid Filament-Wound Composite Pressure Vessel for Aircraft Application

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.

Multi-Objective Optimization of Filament Wound Composite Pressure Vessels Based on Weight and Matrix Cracking/ Burst Pressure Using Imperialist Competitive Algorithm

The most important concern in design of filament-wound composite pressure vessels reflects on the determination of the optimum shape and optimum laminate stacking sequence of composite vessels based on the matrix cracking pressure and burst pressure of composite laminates. In this study the Imperialist Competitive Algorithm (ICA) is used to find the optimum laminate stacking sequence of composite vessels that the design considerations are stability and strength constraints. the matrix cracking pressure of filament-wound composite pressure vessels made of different number of helical layers and different layers of Circumferential layers was calculated by using orthotropic material formulae and then, the burst pressure of composite vessels was calculated by using netting analysis. The optimum laminate stacking sequence of filament winding composite was found to maximize the matrix cracking pressure and the burst pressure by using Imperialist Competitive algorithm.

A multiscale modeling approach to analyze filament-wound composite pressure vessels

A multiscale modeling approach to analyze filament-wound composite pressure vessels is developed in this article. The approach, which extends the Nguyen et al. [Prediction of the elastic-plastic stress/strain response for injection-molded long-fiber thermoplastics. J Compos Mater 2009; 43: 217–246.] model developed for discontinuous fiber composites to continuous fiber ones, spans three modeling scales. The microscale considers the unidirectional elastic fibers embedded in an elastic–plastic matrix obeying the Ramberg–Osgood relation and J2 deformation theory of plasticity. The mesoscale behavior representing the composite lamina is obtained through an incremental Mori–Tanaka [Average stress in matrix and average elastic energy of materials with misfitting inclusions. Acta Metall 1973; 21: 571–574.] type model and the Eshelby [The determination of the elastic field of an ellipsoidal inclusion and related problems. Proc R Soc Lond, Ser A 1957; 241: 376–396.] equivalent inclusion method. The implementation of the micro–meso constitutive relations in the ABAQUS® finite element package (via user subroutines) allows the analysis of a filament-wound composite pressure vessel (macroscale) to be performed. Failure of the composite lamina is predicted by a criterion that accounts for the strengths of the fibers and of the matrix as well as of their interface. The developed approach is validated in the analysis of an aluminum liner – T300 carbon/epoxy pressure vessel to predict the burst pressure. The predictions compare favorably with the numerical and experimental results by Lifshitz and Dayan [Filament-wound pressure vessel with thick metal liner. Compos Struct 1995; 32: 313–323]. The approach will be further demonstrated in the study of the effects of the lamina thickness, helical angle, and fiber–matrix material combination on the burst pressure.

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.

Influence of mosaic patterns on the structural integrity of filament wound composite pressure vessels

PurposeFilament wound pressure vessels have a characteristic pattern observed in their helical layers. These are mosaic‐shaped patterns and affect the layer structural behavior. The present research aims to focus on the influence of mosaic patterns on stress‐strain field and structural design of thin‐walled internally pressurized filament wound pressure vessel. The widely used stress analysis procedures and the commercially available finite element tools usually neglect the effect of the mosaic patterns. The present work seeks to deal with the modeling and stress analysis of complete pressure vessel, incorporating mosaic patterns.Design/methodology/approachThe incorporation of the mosaic effect provides more realistic modeling of the real stress distribution and the stress values compared to the conventional analyses (the effect would depend on the shell structure, i.e. number of plies, relative thicknesses, etc.). The structural analysis is performed using commercial finite element analysis (FEA) tools ANSYS.FindingsThe comparison of results of analytical solution and conventional FEA provides close values of the stresses in the plies. As for the stress and strain distributions obtained by incorporating the effect of mosaic patterns are considerably different. The distribution of the stress and strain fields are not uniform along the length of the vessel and along its circumference and the maximum stresses acting in the direction of the fibers are higher than those calculated using conventional FEA techniques.Originality/valuePrevious work was limited to composite cylindrical shells, without incorporating the end domes. The present work deals with the modeling and stress analysis of complete pressure vessel, incorporating mosaic patterns.