Filament-wound Composite Pressure Vessels Research Articles

A numerical and experimental study on mechanical behaviours of type III composite vessels with different lay-up sequences

ABSTRACT 5 % .There are various factors that have impact on the burst pressure and the failure mechanism of filament wound composite pressure vessels. The sequence of lay-up was less considered because previous researchers paid little attention on the mechanical performance of the whole vessel. In this paper, a 2D axisymmetric finite element model was proposed to predict the damage evolution, failure strength and failure mode of the composite overwrapped pressure vessels. UMAT subroutine based on Hashin failure criteria was introduced to simulate the progressive damage properties of the composite material. The FE models were validated by comparison with the experimental results, and the error between the numerical simulation results and the experimental results was near 5%. In addition, two schemes were performed to evaluate the effects of different lay-up sequence on the ultimate strength and obtain the optimized scheme of lay-up sequence.

Exploring stress and deformation in filament-wound composite pressure vessel liners using PyMAPDL

PyMAPDL, which stands for Python based Mechanical Ansys Parametric Design Language, provides a Pythonic interface to Ansys for automating tasks and managing multiple simulations. The present study focuses on utilizing PyMAPDL to numerically explore the stress and deformation conditions in the domed section of a cylindrical liner, specifically by analyzing ellipsoidal and torispherical dome shapes through the creation of a parametric model in Python. The output suggests a better selection of the dome geometrical parameters. The study extends to filament-wound composite pressure vessels, emphasizing the challenges in determining winding angles and layer thickness variations along the meridian line in dome parts. Cadfil software is used to obtain the thickness and angle variation of the composite layers, and the output data from Cadfil is imported into Ansys ACP as lookup table to generate the composite layer for linear elastic analysis of single composite layer on the liner. The findings suggest that a lower helical angle enhances strength protection in the dome section.

Complex design and analysis of filament wound composite pressure vessels using data driven evolutionary algorithms

The typical composite pressure vessel manufactured by means of filament winding consists of three elementary construction parts, that is, cylindrical part, end dome and the junction between its cylindrical part and the end dome which are subject of this article. The pressure vessel may fail in each of these three parts. Therefore, all of them must be considered during the design process. This study shows the possible way how to design an optimal pressure vessel related to chosen parameters (which can be mass of the pressure vessel, depth of the end dome, magnitude of internal pressure etc.), so that it does not fail in any construction parts. Any decision, whether the pressure vessel comply or not in studied places, is based on Hoffman's failure index analysis. The finding of an optimal solution requires performing a multi-objective optimization task, which was solved here using data-driven evolutionary algorithms. From the input data, which were generated through analytical approaches, surrogate models were created using the Evolutionary Deep Neural Nets (EvoDN2). These surrogate models were further used as an input to the optimization module which is based upon Constrained Reference Vector Evolutionary Algorithm (cRVEA). The results show that the pressure vessel designed in this way comply in each analyzed location. Moreover, it also finds the most stressed location, which can be useful for the designers.

Design method of variable slippage coefficient non‐geodesic filament‐wound composite pressure vessels

AbstractPrevious studies on the design methods of filament winding paths for composite pressure vessels have mainly focused on geodesic and constant slippage coefficient non‐geodesic patterns, neglecting the design of variable slippage coefficients along the fiber path. In this paper, a design method of variable slippage coefficient non‐geodesic filament wound composite pressure vessels is proposed. The study begins by establishing a meridian rotation mapping model and deriving fiber path equations on the shell surface. Subsequently, the fiber paths, curvature characteristics, slippage coefficients, and shell stress responses of the shell under variable geometrical parameters are simulated and analyzed. Next, the winding parameters are optimized while considering bandwidth and stable winding constraints. The optimal winding parameters are determined, and filament winding simulations are conducted on composite pressure vessels. Results demonstrate the feasibility of the proposed method for variable slippage coefficient fiber path winding mode, providing a new and effective filament winding path design approach for composite pressure vessels.Highlights Establishment of meridian rotation mapping model and simulation of shell fiber paths under variable geometric parameters. The fiber paths, curvature characteristics, slippage coefficients, and winding angles of the shell under variable geometrical parameters are simulated and analyzed. Stress response analysis of shells based on Tsai‐Wu failure criterion and classical lamination theory stress field dimensionless modeling. Construction of winding parameter optimization strategies and bandwidth error evaluation based on stable winding and fiber bandwidth constraints. Simulation of variable slippage coefficient non‐geodesic filament winding for composite pressure vessels with different parameters.

Analysis and optimization of junction between cylindrical part and end dome of filament wound pressure vessels using data driven evolutionary algorithms

The junction between cylindrical part and end dome is the most critical place of the filament wound composite pressure vessels because the shear forces and bending moments occur in this area. The strength analyses of junction between cylindrical part and different types of known end domes based on influence coefficients method were performed for filament wound composite pressure vessels manufactured using glass-epoxy and carbon-epoxy composites. Four known end domes were considered that is, a spherical shell, a geodesic-isotensoid shell, a shell based on minimizing of the Tsai-Hill’s strength criterion and shell designed in authors’ previous work (Hoffman 1 shell). Moreover, the study is also dealing with design of optimal end dome shape which takes account to the junction area. Finding of optimal end dome shape was based on data-driven evolutionary algorithms. Using input dataset from the analytical simulation surrogate models were created using Evolutionary Deep Neural Nets (EvoDN2) algorithm. The multicriterial optimization procedure was performed using Constrained Reference Vector Algorithm (cRVEA) optimization algorithm. Results indicates that the optimal end dome shape highly depend on material properties.

Optimization Design of Filament Wound Composite Pressure Vessel Based on OpenSees

Composite pressure vessels have the characteristics of light weight, corrosion resistance, good sealing, and high reliability, and have been widely used in military and civilian applications. With the widespread use of composite pressure vessels today, determining how to conduct scientific research and correct analysis becomes very important. With the continuous development of computer technology and the continuous improvement of finite element algorithms, the numerical calculation method has become an important method for studying composite pressure vessels. In this paper, the finite element analysis of filament wound composite pressure vessels is carried out by means of ANSYS and OpenSees. The semi-analytical method is used to optimize the design with the help of the Python tool. The parametric language is used to design different fiber layer schemes. The optimal fiber layer scheme is obtained by Nelder-Mead optimization function optimization. The optimal angle and thickness obtained after multiple iterations are 9.96875° and 0.03325 m, respectively.

Investigation of effects of manufacturing defects on bursting behavior of composite pressure vessels with various stress ratios

This paper focuses on investigation of effects of defects, which may occur during manufacturing process, on bursting behavior of filament wound composite pressure vessels. A comprehensive experimental study was carried out to understand how manufacturing defects affect bursting behavior of pressure vessels with various stress ratios. Firstly, effect of stress ratio on bursting behavior was studied with the pressure vessels with no defect. Safe and unsafe failure modes were determined for pressure vessels with different stress ratios. Then, delamination and gap defects were deliberately embedded to pressure vessels with safe and unsafe failure modes. Thus, effects of manufacturing defects on bursting behavior for pressure vessels with both safe and unsafe failure modes were studied successfully. Strain gage measurement and high-speed camera were utilized to interpret bursting behavior in detail.

A novel recursive multi-scale modeling for predicting the burst pressure of filament wound composite pressure vessels

A novel recursive multi-scale modeling for predicting the burst pressure of filament wound composite pressure vessels

Estimating the burst pressure of a filament wound composite pressure vessel using two-scale and multi-scale analyses

The influence of inescapable imperfections associated with fiber arrangement in the filament winding process on the burst pressure of a composite vessel is analyzed. Firstly, the influence of fiber packing, fiber spacing and fiber contiguity is analyzed through a two-scale analysis. Mechanical properties of the layers are estimated considering aforementioned parameters at the scale of micro and the burst pressure is estimated at the scale of macro. As the second approach, fiber-bundle crossovers and undulation arisen from filament winding process are also considered at the scale of meso. Thus, a multi-scale modeling is performed capturing micro, meso and macro scales.

Low-velocity impact damages of filament-wound composite overwrapped pressure vessel (COPV)

Low-velocity impact tests were carried out on filament-wound composite overwrapped pressure vessel (COPV) specimens at different impact energies and impact points to determine the low-velocity impact damages of wound composite structures. The anti-impact performance of the filament-wound COPV was compared with that of composite laminated and filament-wound composite plates. Different impact damage modes and damage mechanisms inside the wound COPV were investigated through ultrasound scanning, X-ray, and scanning electron microscopy. Results showed that the impact force–time response curve of the wound COPV can be divided into an ascending area, a plateau area, and a descending area. The duration of the plateau area increased with the increase in impact energies. The impact resistance of the filament-wound COPV was the best, followed by that of the composite laminated plate, and the filament-wound composite plate was the worst. The major damage modes of the filament-wound COPV under low-velocity impact included matrix breakage, delamination, and fiber breakage. Delamination in the COPV tube section mainly occurred between the spiral wound and hoop layers. Delamination at the head of the COPV occurred between different winding layers. Fiber breakage inside the COPV mainly developed in the fiber overlapping zone inside the spiral layer. Results indicated that the fiber overlapping zone was the weak part in the filament-wound composite structure.

Buckling analysis of thin-walled metal liner of cylindrical composite overwrapped pressure vessels with depressions after autofrettage processing

Abstract The cylindrical filament wound composite overwrapped pressure vessels (COPV) with metal liner has been widely used in spaceflight due to their high strength and low weight. After the autofrettage process, the plastic deformation of the metal liner is constrained by composite winding layers, which introduce depressions to the metal liner that causes local buckling. To predict the local buckling of the inner liner with depressions of the pressure vessel after the autofrettage process, a local buckling analysis method for the metal liner of COPV was developed in this article. The finite element method is used to calculate the overall stress distribution in the pressure vessel before and after the autofrettage process, and the influence of local depressions on the buckling is evaluated. The axial buckling of the pressure vessel under external pressure is analyzed. The control equation of the metal liner with depressions is developed, considering the changes in the pressure and the bending moment of the liner depressions and its vicinity during the loading and unloading process. Taking the cylindrical COPV (38 L) with aluminum alloy liner as an example, the effects of liner thickness, liner radius, the thickness-to-diameter ratio, autofrettage pressure, and the length of straight section on the autofrettage process are discussed. The results show that the thickness of the inner liner has the most significant influence on the buckling of the liner, followed by the length of the straight section and the radius of the inner liner, while the autofrettage pressure has the least influence.

Estimating S-N curves for local fiber dominated fatigue failure in ring specimens representing filament wound pressure vessels with damage

Modeling the effect of fatigue is important for predicting remaining life of damaged filament wound composite pressure vessels. This study shows how S-N curves can be measured that describe local fiber dominated fatigue failure on the scale of 0.25 mm near stress concentrations caused by a hole representing damage.High frequency Digital Image Correlation DIC was applied to measure strain fields in rings tested by the split disk method. The rings were cut from a glass fiber reinforced polymer pressure vessel. A hole was cut into the rings to simulate damage in the laminate of the pressure vessel.The Miner sum cumulative damage is calculated based on strain histories measured by DIC and several assumed S-N curves. The S-N curve giving Miner sum damage closest to the experimentally observed local failures in several samples is taken as the S-N curve describing the material´s behavior best. The local S-N curve was considerably less conservative than nominal S-N curves obtained from standard coupon testing. Its origin was a factor 2.5 higher.

Fracture analysis of composite pressure vessel using FEM

A finite element-based numerical method is applied to predict the possibility of propagation of existing delamination/patch in a filament wound composite pressure vessel in this work. Strain energy release rates (SERRs’) in the three principal modes are predicted along the circumference of delamination for two different load cases, i.e., internal pressure load when two diametrically opposite patches are existing in the nozzle end side dome portion, and combined load due to thrust and bending when a patch is located in the nozzle end side skirt region of the composite pressure vessel (CPV). The problem is modeled in ANSYS software and a three-dimensional finite element approach in association with virtual crack closure technique (VCCT) is used to analyze the fracture behavior of the CPV under two load cases as stated. In both the load cases, SERR is found to be maximum at the bottom side of the patch, Mode-I being dominant under pressure load, and Mode-II in axial load. Delamination growth is observed at 26.5% of applied pressure in Case-1 and 57.5% of axial load in Case-2. This fracture analysis approach can be extended to composite structural components in defense and aerospace applications.

Experimental and numerical investigation of the cylinder-dome transition region of a pressure vessel

The difference in stiffness between cylindrical and dome regions of a filament wound composite pressure vessel may cause undesirable bending in the cylinder-dome transition region. Because of the bending, strain distribution may be non-uniform in the transition region. Therefore, accurate modeling that captures non-uniform strain distribution in the transition region is crucial for a safe pressure vessel design. In this study, a pressure vessel with a metallic liner was designed. Three identical pressure vessels were manufactured. One of the vessels was cut for detailed geometric investigation. The section of the transition region was investigated using an optical microscope. The termination of each hoop layer and resin pockets under the helical layers were clearly observed at the micro-scale. Also, measurement of layer by layer thickness and fiber volume fraction were performed. Other vessels were pressurized until the burst pressure. Fiber direction strain was measured using strain gauges that were mostly attached to the transition region to capture the non-uniform strain distribution. Two finite element models were created to analyze the transition region. The first finite element model was created with design parameters. The second finite element model was established by considering the findings obtained from the microscopic analysis. Strain distributions obtained from the strain gauges and finite element analyses were compared. In contrast to the first finite element model, strain distribution in the transition region was perfectly matched with the second finite element model. Thus, important aspects of analyzing the transition region of a pressure vessel were addressed for designers.

Design and development of a filament wound composite overwrapped pressure vessel

A detailed design optimization of a composite over wrapped pressure vessel (COPV) is performed through finite element analysis (FEA) and testing. The design optimization of a type IV polymer-lined composite overwrapped pressure vessel is performed by means of the finite element method using ABAQUS software. A plug-in named WCM in ABAQUS is used that automates the entire process of constructing a COPV FEA model. This work investigates the influence of winding angle, number of layers, and sequence of layers on the burst strength of COPV. Maximum stress, maximum strain, Tsai Hill, Tsai Wu and Hashin progressive failure criteria are used to find the burst strength of the COPV. Comparing all the results obtained using above the failure criteria, it is found that the maximum strain criterion is more conservative, and the Hashin criterion is the least conservative. Digital Image Correlation (DIC) was utilized during burst testing to quantify the failure strain in different directions. The numerical results were compared with the experimental burst testing results and a reasonably good comparison was found.

Design of planar wound composite vessel based on preventing slippage tendency of fibers

The planar winding is one of technologies for manufacturing the filament wound composite pressure vessels, one unique type of the non-geodesic winding. In designing composite pressure vessels in general and planar filament wound composite vessels in particular, the most critical problem is determining the dome meridian contour. In this study, based on the netting theory, the mathematical model of the non-geodesic wound dome was built to create a premise for establishing the model of the planar wound dome. From the built mathematical model, the numerical method was utilized to draw the dome meridian profiles, simultaneously the relations between given initial parameters of the composite vessels and the slippage coefficient were established as well. Based on these relations and the non-slippage condition of the fiber, the limited ranges of initial parameters of the composite vessels were found out to create a basis for designing.

Filament-wound composite pressure vessel inspection based on rotational through-transmission laser ultrasonic propagation imaging

In this paper, we introduce a rotational through-transmission ultrasonic propagation imaging system to inspect the full thickness of the entire cylindrical section of filament-wound composite overwrapped pressure vessels. This system can achieve high signal-to-noise ratio throughout the cylindrical section of pressure vessels by using a rotational scanning method. Based on the advantages of the laser ultrasonic system that can generate and detect ultrasound waves by using a small-diameter laser beam and making an inspection path in a narrow environment, this system directs the laser beam inside the pressure vessel via a mirror to enable the through-transmission mode for vessel inspection. A type-3 pressure vessel was inspected using the system developed, which successfully detected two impact damage spots and showed the filament winding direction clearly. The test results show that the system developed is highly reliable and can replace the current hydrostatic sample test for pressure vessel safety certification.

EVALUATION OF OPTIMUM CONFIGURATIONS FOR COMPOSITE OILFIELD THREE-PHASE SEPARATOR PRESSURE VESSEL

Gravity three-phase separators consist of pressure vessel with multiple internals that utilize gravity settlement to separate gas/water/oil free from each other. The pressure vessel represents the substantial element of such separators. Limited work has been reported on investigating fluid contained multilayered filament-wound composite pressure vessels. However, destructive testing with full scale or subscale is the best method to determine the structural characteristics of filament???wound pressure vessels as it requires an excessive cost. In this study, three parametric numerical models have been undertaken to represent three load cases namely; pure pressure, operating, and hydro-test load cases in order to predict optimum lay-up for filament-wound pressure vessels of s???glass/epoxy, carbon/epoxy composite laminates and hybrid of both for certain configurations. ANSYS (ACP) 17.0 commercial software was used for simulation and analysis. ANSYS Workbench design point parameters were used to construct parametric models. A developed mathematical solution used from cited work was employed for results verification using Tsai-Wu failure criterion for the safe design assessment in terms of safety factor. The findings indicate that for operating load case, optimum lay-up should be selected according to foreseen loading ratio acting upon pressure vessel during its lifetime, and hydro-test load case is safe for all studied lay???ups also.

Design of winding pattern of filament-wound composite pressure vessel with unequal openings based on non-geodesics

In this article, we proposed a new approach to design the winding patterns of filament-wound composite pressure vessel with unequal polar openings with non-geodesics. To ensure the continuity of winding angles between trajectories along the cylinder and the dome, the non-geodesics for cylindrical part were used. The developed winding patterns of the vessels were simulated using the MATLAB software to verify the feasibility of the acquired trajectories. To demonstrate the performance in designing the winding path for big polar ratios, we analyzed vessels with polar pole ratios of 1:2–1:4, respectively. The developed winding patterns have successfully achieved uniform fiber distributions along the mandrel without severe overlap, except for the polar pole regions. To avoid the severe overlap between filament bands, we further studied the relationship among the winding pattern, bandwidth, and the number of tangent points, and derived a suitable bandwidth based on the winding pattern. These simulated results proved the effectiveness of the developed method in design of winding pattern with unequal polar openings.

Design optimization for filament wound cylindrical composite internal pressure vessels considering process-induced residual stresses

The manufacturing process has significant influence on the product quality of filament wound composite parts. The aim of this work is to provide an analytical and optimization tool to find the optimal winding parameters to obtain better mechanical performance of the filament wound composite internal pressure vessels accounting for the process-induced residual stresses. First, the winding process model is established to calculate the winding process-induced residual stresses based on the three-dimensional thick cylinder theory. Then, an analytical model is constructed to predict the cure-induced residual stresses considering the thermo-viscoelastic effects based on linear thermo-viscoelastic constitutive model. Moreover, the optimization model is established to maximum the failure pressure based on proposed winding and curing process model. A novel iterative algorithm is given to determine the failure pressure based on the Tsai-Wu failure criterion and vonmises strength theory. The winding and curing process models are verified by the results of FEA and other work. The simulation results show that it is feasible to find the optimal winding angels and tensions to improve the load capacity of the filament wound cylindrical composite internal pressure vessels with aid of the proposed process analysis and optimization model.