Composite Vessels Research Articles

Investigating the Debonding of Aluminum and Carbon Fiber Reinforced Polymer (Al-CFRP) in Type-III Filament-Wound Composite Vessels Subject to Temperature Variations

Investigating the Debonding of Aluminum and Carbon Fiber Reinforced Polymer (Al-CFRP) in Type-III Filament-Wound Composite Vessels Subject to Temperature Variations

An integrated approach to analyzing matrix-crack-induced stiffness degradation and medium leakage in linerless composite vessels

This paper proposes an integrated analysis method for linerless composite vessels considering matrix-crack-induced stiffness degradation and permeation. Stiffness degradation models are obtained using machine learning regression, the data sets of which consist of finite element analysis (FEA) results and virtual samples. Then, the effective leakage conductance is obtained by using the linear elastic fracture mechanics and the micro-cracking leakage mechanism. The proposed integrated method is applied to analyze vessel structures designed by the grid theory, which has variable ply thicknesses and layup angles. Simulation results show that whether the structure at cryogenic temperature cracks and leaks more easily depends on its dimensions and stacking sequences.

Axisymmetric defect originated Al–CFRP interface thermo-elastic fracture study of type-III composite vessel and inverse identification of cohesive zone parameters

Debonding existence at the interface of Al liner and overwrapped CFRP laminates may endanger the structural integrity of type-III composite vessel. In this study, CFRP and GFRP wound composite pressure vessels with Teflon sheet inserted artificial axisymmetric defect in Al–CFRP interface and without any defect were manufactured and nitrogen gas inside cooling experiments of the vessels were conducted. During the cooling axial strain and temperature responses at distinct locations of outer GFRP hoop surface were monitored to study the thermoelastic crack growth along Al–CFRP interface. The nonlinear strain response obtained under temperature change in the defect bearing specimen was considered as a result of Al–CFRP interface crack growth. Furthermore, to expose the Al–CFRP interfacial cross section of post-cooling specimen, destructive cutting and optical microscopy were performed. The Al–CFRP cross sectional microscopic observations at cutting planes showed Al–CFRP interface crack growth due to cooling in the defective specimen. Afterwards, the GFRP hoop surface axial strain experimental data fitted inversely to the surface based cohesive zone modeling (CZM) simulation results to estimate the Al–CFRP interface cohesive strength, and fracture energy.

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.

Analysis of the Boss Structure of Type Ⅳ Composite Vessel for a High-Pressure Hydrogen Tube Trailer

Currently, large-volume type IV composite vessel tube trailers garner significant attention and development within the hydrogen energy storage and transportation industry due to their cost-effectiveness and practicality. This study aims to assess the static strength and sealing performance of the boss structure in order to optimize its design. Firstly, a model of the mouth structure of type IV vessels was constructed to analyze the stress distributions in the boss and liner. Subsequently, innovative boss and liner structures were developed based on the primary mouth structure to investigate the impact of geometric dimensions through finite element analysis. This study revealed that changes in geometrical dimensions led to significant alterations in the stresses of the plastic liner in comparison to metallic bosses. Building upon these findings, the structural safety and sealing performance of the boss and liner structure were further validated through finite element analysis. The outcomes of this research can serve as a reference for guiding the structural design of bosses and aiding in the development of hydrogen storage vessels.

Numerical simulation of mechanical properties of composite high-pressure vessel for space application

Abstract A composite high-pressure vessel reinforced with T1000 carbon fiber and featuring an ultra-thin titanium lining for space applications is examined. Using the laminated plate theory for composite materials and the elastic-plastic theory for isotropic materials, a three-dimensional finite element model is developed. The pressure test results confirm the correctness of the finite element model. Under various internal pressure circumstances, the displacement and strain distribution of the metal liner and the laminated composite are compared and analyzed. It is shown that the composite vessel primarily deforms along the axial direction when the internal pressure is greater than the working pressure of the vessel. Only elastic deformation is present in the composite layer, but both plastic and elastic deformation are present in the ultra-thin titanium liner.

A Design Approach to Assess Effects of Non-Contact Underwater Explosions on Naval Composite Vessels

A Design Approach to Assess Effects of Non-Contact Underwater Explosions on Naval Composite Vessels

Numerical Investigation on the Capability of Modeling Approaches for Composite Cylinders under Low-Velocity Impact Loading

Composite pressure vessels can be exposed to extreme loadings, for instance, impact loading, during manufacturing, maintenance, or their service lifetime. These kinds of loadings may provoke both visible and invisible levels of damage, e.g., fiber breakage matrix cracks and delamination and eventually may lead to catastrophic failures. Thus, the quantification and evaluation of such damages are of great importance. Considering the cost of relevant full-scale experiments, a numerical model can be a powerful tool for such a kind of study. This paper aims to provide a numerical study to investigate the capability of different modeling methods to predict delamination in composite vessels. In this study, various numerical modeling aspects, such as element types (solid and shell elements) and material parameters (such as interface properties), were considered to investigate delamination in a composite pressure vessel under low-velocity impact loading. Specifically, solid elements were used to model each layer of the composite pressure vessel, while, in another model, shell elements with composite layup were considered. Compared with the available experimental data from low-velocity impact tests described in the literature, the capability of these two models to predict both mechanical responses and failure phenomena is shown.

Surrogate metamodels from digital image correlation for testing high-performance composite vessels

In this work, a workflow has been developed for the generation of surrogate metamodels to predict and evaluate failure with a confidence above 95 % in initial service conditions of high-performance cylindrical vessels manufactured in composites by Roll Wrapping technology. Currently, there is no specific testing standardization for this type of vessel and to fill this gap probabilistic numerical models were developed, performed by the Finite Element Method, fed with the material characteristics obtained experimentally by 2D digital image correlation from flat specimens. From the initial numerical model, a surrogate metamodel was generated by stochastic approximations. Once the metamodels were obtained by robust engineering, an experimental ring-ring tensile test was developed under service conditions and deformations were measured by high-precision 3D digital image correlation. Parametric and robust tests showed that the results of the metamodel did not show statistically significant differences, with errors in the rupture part of less than 2 % with respect to the results obtained in the test, being proposed as a basis for new test procedures.

Design, Manufacture, and Cryogenic Testing of a Linerless Composite Tank for Liquid Hydrogen

This paper describes design, manufacture, and testing of a linerless composite vessel for liquid hydrogen, having 0.3 m diameter and 0.9 m length. The vessel consists of a composite cylinder manufactured by wet filament winding of thin-ply composite bands, bonded to titanium end caps produced by additive manufacturing. The aim was to demonstrate the linerless design concept with a thin-ply composite for the cylinder. The investigation is limited to the internal pressure vessel, while real cryogenic tanks also involve an outer vessel containing vacuum for thermal insulation. Thermal stresses dominate during normal operation (4 bar) and the layup was selected for equal hoop strains in the composite cylinder and end caps during filling with liquid hydrogen. Two vessels were tested in 20 cycles, by filling and emptying with liquid nitrogen to 4 bar, without signs of damage or leakage. Subsequently, one vessel was tested until burst at almost 30 bar.

A novel design of a low-pressure composite vessel with inspection opening – design, manufacturing and testing

Composite structures, especially pressure vessels, pipelines, and additional components such as tees, reductions, or inspection openings are more and more willingly used in the chemical industry. In this research, a novel design of a low-pressure composite vessel with an inspection opening is presented. The vessels are unsymmetrical considering the domes. On one side the opening is considerably bigger, around half of the cylindrical diameter of the vessel. This design requires a new approach to manufacturing such structures. In this study, a two-step analysis was performed. Firstly, small-size pressure vessels (S) were manufactured and the design of dome reinforcement was validated. Then, the final design of vessel (M) was produced, with a volume of around 700 litres. The vessels were initially calculated for 21 bars of burst pressure. During burst pressure tests, the strains were measured with optical fibres (FBG) and strain gauges. Additionally, the acoustic emission was utilized to predict the damage modes and locations. Finally, a microscopic evaluation of the specific parts of the vessels was performed. Conclusions were drawn, that the proposed novel design of dome reinforcement around the inspection opening fulfilled the strength and stiffness requirements.

Research on the development and application of the hydrogen energy

In recent years, global warming has been an ongoing concern for experts, and the cause of this problem is the over-reliance on fossil fuels, so finding a new source of energy that can replace traditional fossil fuels is essential at this stage. In terms of hydrogen production, solar hydrolysis is a promising method for converting sunlight into renewable, sustainable, and green hydrogen energy. The most representative pathway for converting solar radiation into molecular hydrogen is photovoltaic chemistry (PEC). In terms of hydrogen storage, researchers have identified the potential of a new type of hydrogen storage vessel, the "hybrid hydrogen storage vessel," which combines an aluminum-carbon fiber reinforced plastic (Al-CFRP) composite vessel with a hydrogen storage alloy. An evaluation of this system has shown that the hybrid hydrogen storage vessel has advantages over conventional hydrogen storage technologies in terms of volume and weight of stored hydrogen. In terms of hydrogen applications, hydrogen-fueled electric powertrains offer a solution for long-distance driving using clean energy, whereas battery-powered vehicles are plagued by range limitations, which is a shortcoming in hydrogen applications. This paper critically examines the potential of hydrogen as a sustainable energy source and presents three aspects of hydrogen technology, respectively its production, storage and application. This essay highlights the importance of chemical engineering principles in optimizing the production, storage and utilization of hydrogen energy for a clean, sustainable energy future.

Crack density estimation method for composite laminates based on discrete form stiffness degradation models

Matrix cracking of composite laminates leads to stiffness degradation and dominates the medium leakage of liner-less composite vessels. A stiffness degradation model can be established through the machine learning method, which provides only discrete form equivalent moduli data without explicit analytical results. This paper further explored the use of the discrete form data set of stiffness degradation in the crack density estimation for composite laminates by using an iterative process. Furthermore, different mixed-mode fracture criteria were discussed. The results showed that Benzeggagh-Kenane (B-K) criterion and the power law criterion are more appropriate in mixed-mode crack density analyses.

Performance-based design and manufacturing of filament wound Type-4 cylinders for compressed gas storage

Filament wound type-4 cylinders are widely used in automotive applications for the storage of compressed gases. The performance of the storage cylinders critically depends on their manufacturing parameters. These paramters include the material properties of the reinforcement and matrix material, the number of fiber spools used during winding, the fiber bandwidth, the initial fiber band volume fraction, the mandrel geometry, the winding sequence, and the composite layer thickness distribution. An interim link between the critical parameters, the composite thickness distribution and the amount of fiber and resin consumed for winding a type-4 composite vessel has been established using an analytical model in this study. The developed model is validated by manufacturing the cylinder and comparing the theoretical and experimental results. The composite layer distribution across the entire geometry of the vessel is included into an FEA model to predict the burst pressure and weight of the obtained type-4 cylinder with greater precision. The given study can be used to design low-cost high burst performing type-4 composite structures with significant weight reduction.

Progressive failure analysis and burst mode study of type IV composite vessels

ABSTRACT The lightweight high-pressure hydrogen storage vessels composed of polymer liner and composite reinforced layers have attracted more and more attention. In this research, a 2D axisymmetric finite element model was proposed to predict the damage evolution, failure strength and failure mode of the composite overwrapped pressure vessels, in which a user subroutine UMAT based on Hashin failure criteria was introduced to simulate the progressive damage properties of the composite material. The FE models are validated by comparison with the experimental results, and the error between the numerical simulation results and the experimental results was within 10%. It is found that vessels with different lay-up schemes might burst in different locations. Parametric studies are performed to obtain a critical ratio of hoop and helical layers to keep the vessel burst in safe mode.

Prediction of material thickness on dome of geodesic wound orthotropic composite vessel

Orthotropic composite pressure vessels are designed based on considering the role of a matrix in the force balance of the structure and its leakage due to matrix failure. To be more specific, the stress and strain states of the shell are considered simultaneously in both longitudinal and transverse directions of the fiber. Due to such a loaded condition, the laminate thickness prediction of the shell does not use the maximum stress criterion as with the traditional monotropic composite vessels but rather the multi-axial failure criterion of the composite material. With the developed and published platforms on the design of the dome profile of the composite vessel, this paper focuses on predicting the laminate thickness of the geodesic wound dome of the pressure vessel according to Tsai-Wu failure criteria, simultaneously the material thickness distribution on the dome as a basis for determining structural parameters of the vessels.

Influence of fiber tension during filament winding on the mechanical properties of composite pressure vessels

During the manufacturing of composite pressure vessels, the fiber tension of the filament winding process has an important influence on the mechanical properties as well as on the gravimetric efficiency of the structure and is therefore investigated within this paper. Three series of samples were manufactured and tested: A) steel liners as reference, B) composite vessels with low fiber tension of 3 N, and C) vessels with high fiber tension of 80 N. The manufacturing process is discussed in this paper with special focus on the parameter of fiber tension and its related challenges. Burst tests with strain measurements and acoustic emission (AE) were conducted, and a statistical analysis of the results is presented. Additional numerical investigations on the structural behavior of the vessels and effect on the gravimetric efficiency are performed to support the experimental result. The investigations show that the increase in fiber tension induced compressive stress on the steel liner, leading to an increase in burst pressure and influence on AE. Furthermore, the fiber volume fraction (FVF) of the composite laminate increased due to increased fiber tension, resulting in higher mechanical properties and an improvement in gravimetric efficiency.

Experiment, simulation, optimization design, and damage detection of composite shell of hydrogen storage vessel-A review

The composite shell of composite high pressure hydrogen storage vessel (CHPHSV) is the main structure in bearing inner pressure. Its failure will lead to leakage or burst of CHPHSV, which will cause serious safety problem and economic losses. So the security of CHPHSV has always been a key and difficult problem in academia and industry, which restricts the large-scale application of hydrogen. In this paper, the failures of composite shell of type III, type IV, and type V vessels are reviewed in experiment study, simulation method, optimization design, and damage detection, focusing on the burst modes (safe or unsafe), the influence of hydrogen-thermo-stress field, and the epistemic uncertainty. Firstly, the burst modes, failure behavior, test method, and influencing factors are summarized in the experiment study, and experiment for type V composite pressure vessel is discussed. Secondly, the simulation method is reviewed in the aspect of first ply failure (FPF) analysis and last ply failure (LPF) analysis. The damage evolution of safe burst mode and unsafe burst mode is summarized. Besides, the influence of hydrogen-thermo-stress field and the uncertainty characteristic are also reviewed. Moreover, simulations of micro-crack and permeability for type V composite pressure vessels are summarized. Then, the optimization design methods based on deterministic parameters and uncertain parameters are reviewed. Finally, the damage detection methods of the composite shell of CHPHSV are summarized. The experiment, numerical simulation, and optimization are important for design of the composite vessel, and the damage detection can significantly reduce the degree of uncertainty and maintenance safety. In the future research, precise model considering multiple damage modes, hydrogen-thermo-stress field effect should be established for simulation of safe and unsafe burst mode. Uncertain quantization should be studied for burst pressure with combination of stochastic uncertainty and epistemic uncertainty. Besides, the robust design method based on the reliability of CHPHSV considering the epistemic uncertainty of design parameters should be established for a larger safety margin.

Prediction of matrix-cracking-induced stiffness degradation of cross-ply laminates based on data-driven method

A constitutive model of composite laminates with matrix cracking is essential for the design of liner-less composite vessels. This paper proposes a data-driven approach to predicting stiffness degradation in cross-ply laminates with matrix cracking. A pixelated expression of the stacking sequence was adopted to deal with the difference in the number of cracked plies, as the features for machine learning (ML) should be uniform. The data set for ML training is established by using finite element analysis (FEA), where the material properties, stacking sequences and crack densities are random. The normalised stiffness of the cracked plies of [0n/90m]s and [0/90m/00.5]s laminates is obtained by using the proposed ML method, and they are then compared with the available experiments, a micro-mechanical analytical model and FEA simulations. The ML method successfully predicted the stiffness degradation of the laminates with different numbers of cracked plies and further explored the application of data-driven methods for mechanics of composite materials.

Fatigue analysis of high-pressure hydrogen storage vessel based on optimum autofrettage pressure

To improve the fatigue performance of high-pressure hydrogen storage vessels, a method is proposed to determine the optimal autofrettage pressure of the vessel using numerical simulation and experimental verification. First, a finite element model considering the actual structure of the vessel is established based on grid theory. Then, the effect of autofrettage pressure on the equivalent alternating stress amplitude of liner under cyclic fatigue load is studied by using the modified equation of Smith–Watson–Topper mean stress. Lastly, the optimum autofrettage pressure is determined according to the DOT-CFFC and CGH2R standards, and the fatigue life is predicted. The results show that under the optimum autofrettage pressure, the bearing capacity of the liner under working pressure and the fatigue life under fatigue cycle load are increased by 74% and 12 times, respectively. The experimental results are in good agreement with the numerical simulation results, with an average error of 6.3%. This research has important reference significance for the preliminary design stage of composite vessels.