Multilayer Laminate Research Papers

Shear-induced mixing governs codeformation of crystalline-amorphous nanolaminates

2025

Deformation of ductile crystalline-amorphous nanolaminates is not well understood due to the complex interplay of interface mechanics, shear banding, and deformation-driven chemical mixing. Here we present indentation experiments on 10 nm... more

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Pour une solution durable du renforcement des infrastructures par grilles en fibre de verre

by Mai Nguyễn

2025

L'emploi de grilles de verre pour le renforcement des chaussees bitumineuses et la lutte contre la remontee des fissures est une solution employee avec succes et en plein developpement. Le Projet ANR SolDuGri rassemble des industriels... more

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Structural amorphization and mechanical properties of nanolaminates of the cooper-niobium system during high-pressure torsion

by Inga Permyakova

2025, Russian Physics Journal

The results of investigation of structural transformations and mechanical behavior of nanolaminates are reported, which were manufactured by multiple rolling of alternating layers of copper and niobium, followed by high-pressure torsion... more

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GENERAL KARATE: A COMPROMISE BETWEEN BUDO AND SPORTS AND PROTECTION AGAINST THE MARGINALIZATION OF KARATE IN WESTERN SOCIETY

by Anatoliy Lozovyy

2024, Abstract book. 13th International Conference of IMACSSS & 5th GSMACC 2024

This analytica1 study is devoted to the rоlе and significance of Gепеrаl karate in protecting Japanese karate in the mоdеrп West from two threats to its authenticity: 1) complete transformation into а typical Western sport, 2)... more

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Outil 2D d'analyse mécanique et paramétrique des chaussées fissurées

by Hanan Nasser

2024, HAL (Le Centre pour la Communication Scientifique Directe)

Ce papier présente un outil de calcul rapide et utile à l'ingénieur pour l'analyse des champs mécaniques dans les structures multicouches de chaussée fissurées. La chaussée est choisie équivalente à trois couches élastiques et homogènes... more

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Mixed FEM for solving a plate type model intended for analysis of pavements with discontinuities

by Hanan Nasser

2024, Road Materials and Pavement Design

This paper aims at presenting the development of a numerical tool dedicated to the computation of the mechanical response of pavements incorporating vertical cracks and/or interlayer debonding. In this tool, the structure is modelled as a... more

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Outil 2D d'analyse mécanique et paramétrique des chaussées fissurées

by Hanan Nasser

2024

Ce papier presente un outil de calcul rapide et utile a l'ingenieur pour l'analyse des champs mecaniques dans les structures multicouches de chaussee fissurees. La chaussee est choisie equivalente a trois couches elastiques et... more

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Response of Cu-Nb nanolamellar composites to severe rolling strains

by Keonwook Kang

2024, OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information)

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Calcul analytique de multicouches composites non-délaminés et délaminés en traction uniaxiale avec des bords libres

by Karam Sab

2024, HAL (Le Centre pour la Communication Scientifique Directe)

Le problème de bord libre est l'un des problèmes les plus importants dans la conception et l'analyse des matériaux composites. Les contraintes interlaminaires trop importantes près de bords libres, théoriquement singulières, pourraient... more

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A coupled DQ-Heaviside-NURBS approach to investigate nonlinear dynamic response of GRE cylindrical shells under impulse loads

by Morteza Mohammadzaheri

2024, Thin-Walled Structures

As a first endeavour, nonlinear dynamic response of the glass fiber-reinforced epoxy (GRE) laminated composite cylindrical shells under an impulse load is investigated based on the firstorder shear deformation theory (FSDT) of shells. A... more

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Manufacturing and testing composite overwrapped pressure vessels with embedded sensors

by Orlando Frazão

2024, Materials and Design

In this research programme, methodologies for structural health monitoring (SHM) of composite overwrapped pressure vessels (COPV) were addressed. So, this work is part of the development of a COPV laboratorial prototype incorporated with... more

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Simulating Progressive Damage of Notched Composite Laminates with Various Lamination Schemes

by Anupam Chakrabarti

2024, International Journal of Applied Mechanics and Engineering

A three dimensional finite element based progressive damage model has been developed for the failure analysis of notched composite laminates. The material constitutive relations and the progressive damage algorithms are implemented into... more

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Comparison of Lossless Image Formats

by David Barina

2024, Computer Science Research Notes

In recent years, a bag with image and video compression formats has been torn. However, most of them are focused on lossy compression and only marginally support the lossless mode. In this paper, I will focus on lossless formats and the... more

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Influence of sliding interfaces on the response of a viscoelastic pavement

by Armelle Chabot

2024, 6th Int. Conf. on Maintenance and Rehabilitation of Pavements and Technological control, MAIREPAV6 (Print ISBN 978-88-8202-0293), Edited by Ezio Santagata, Jul 2009, Politecnico Di Torino, Italy.

ABSTRACT This article aims at analyzing the influence of the perfect-slip interface condition on the computed response of a pavement structure. This condition has been implemented in the ViscoRoute software that solves the 3D mechanical... more

On the other hand, the sliding interlayer condition states that the shear components of the trac- tion vector are equal to zero at both side of an interface. In the same time, the conditions on the vertical displacement and the third component of the traction vector remain the same as in Equa- tion 7. The sliding interlayer condition for an interface settled between layer i and i+1 reads: Globally, the interlayer condition (bonded or sliding case) can be expressed as a function of th amplitude vectors 8; and B;,; whose components are the B—parameters of Equation 6:

Figure 1. Sketch of the composite pavement and the loading conditions. A composite pavement composed of four layers is studied. The different layers are defined as follows: a surface course of bituminous materials (BBSG), a base layer of bituminous materials (GB), a layer of materials treated with hydraulic binders (GC), and a pavement foundation. BBSG, GB and GC stand for semi-coarse bituminous concrete, base asphalt concrete and ce- ment bound graded aggregates, respectively.

Table 1. Parameters of the Huet-Sayegh model for layers 1 and 2. Figure 2. Schematic representation of the Huet-Sayegh model. where Ao, A; and A> are constant parameters. A schematic representation of the Huet-Sayegh rheological model is given in Figure 2. Parameters of this model are determined based on ex- perimental data stemming from complex modulus tests performed at different temperatures anc frequencies, and by using software Viscoanalyse (Chailleux et al. 2006). The parameter values corresponding to the materials involved in this study are summarized in Table 1.

Figure 3. (a) Comparison of the deflection obtained for the bonded and the sliding condition: longitudinal section in the X direction (Y=0). (b) The same as (a) but in the Y direction (X=0).

Figure 4. (a) Longitudinal section (in Y=0 and Z=0.199 m) of €,, computed in the sliding and the bonded cases. (b) The same as (a) but for ¢,, plotted in the Y direction (X=0).

Figure 5. Comparison between €,, computed with the sliding and the bonded interface condition: longitu- dinal section in the X direction (Y=0).

Figure 6. (a) Longitudinal section (in Y=0 and Z=0.399 m) of 0, computed in the sliding and the bonded cases. (b) The same as (a) but for o,, plotted in the Y direction (X=0).

Figure 7. Isovalues of the deflection at 15°C (a) and 35°C (b) obtained in the case of sliding interfaces.

Figure 8. (a) Comparison of the deflection computed for a temperature of 15°C and 35°C (sliding case): longitudinal section in the X-direction (Y=0). (b) The same as (a) but plotted along the Y-direction (X=0).

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Apports du massif de Winkler dans la construction d'un outil de calcul de structure multicouche fissurée reposant sur un sol

by Armelle Chabot

2024, HAL (Le Centre pour la Communication Scientifique Directe)

Afin de construire un outil de calcul rapide dédié à l'analyse des pathologies des chaussées, on associe, pour le sol, une fondation de Winkler (W) au Modèle Multi-particulaire des Matériaux Multicouches (M4) à 5n champs cinématiques par... more

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MULTIPARTICLE MODELS OF MULTILAYERED MATERIALS M4_5n AND M4_(2n+1)M FOR EDGE EFFECT ANALYSIS

by Armelle Chabot

2024, JNC11, Arcachon, France

The Multiparticle Models of Multilayered Materials (models M4) are developed to analyze easily the 3D stress fields which produce delamination or transverse crackings in laminates. The M4 models are built from 3D approximate stress... more

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Development for the Structural Study of Charging Box Inclusion in Electrified Roads

by Armelle Chabot

2024

Le rechargement dynamique des véhicules électriques par induction est possible en introduisant un boiter de recharge (CU) dans la route. Cependant, enfin d'anticiper les dégradations et d'étudier la durabilité des assemblages ainsi mis en... more

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Mechanical Analysis of Thick-walled Filament Wound Composite Pipes under Pure Torsion Load: Safety Zones and Optimal Design

by Oleksandr Menshykov and

2024, Applied Composite Materials

Thick-walled composite pipes made of fibre reinforced laminate are good candidates to replace traditional metal counterparts in fabricating such as drive shafts and drilling pipes. In this paper, the behaviour of thick-walled composite... more

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Evaluating the effectiveness of nanofillers in filament wound carbon/epoxy multiscale composite pipes

by Hasan Ulus

2024, Composites Part B-engineering

The performance of filament wound (FW) composite pipes is considered to be fundamentally governed by fiber properties and winding angles; however, matrix dominated properties such as axial and hoop strengths are also responsible in design... more

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Evaluating the effectiveness of nanofillers in filament wound carbon/epoxy multiscale composite pipes

by Hasan Ulus

2024, Composites Part B: Engineering

The performance of filament wound (FW) composite pipes is considered to be fundamentally governed by fiber properties and winding angles; however, matrix dominated properties such as axial and hoop strengths are also responsible in design... more

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Improving strength-ductility synergy of nano/ ultrafine-structured Al/Brass composite by cross accumulative roll bonding process

by ehsan borhani

2023

Increasing the strength of metallic multilayered composites fabricated through accumulative roll bonding (ARB) is typically accompanied by a sacrifice in ductility. In the current work, we propose a strategy to achieve microstructural... more

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Effect of Process Parameters on Thermal and Mechanical Properties of Filament Wound Polymer-Based Composite Pipes

by Svetlana Risteska

2023, Polymers

The aim of this study was to investigate the mechanical and thermal properties of composite pipes based on epoxy resin and glass fibers produced by filament winding (FW) technology. Epoxy resins are widely used polymers in FW composite... more

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Videozapis o proizvodnji valovitog kartona kao edukativni materijal za kolegij Ambalaža 1

by Mirna Grgic

2023

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Comparison of Lossless Image Formats

by David Barina

2023, arXiv (Cornell University)

In recent years, a bag with image and video compression formats has been torn. However, most of them are focused on lossy compression and only marginally support the lossless mode. In this paper, I will focus on lossless formats and the... more

Figure 1: Three datasets used in our comparison. From top: Photos (14 images), Illustrations (10 images), and Books (7 images).

Table 3: Compression performance on the Books dataset. The best result in bold. Table 2: Compression performance on the Illustrations dataset. The best result in bold.

Table 1: Compression performance on the Photos dataset. The best result in bold.

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Buckling Behaviour of Locally Dented GFRP Cylindrical Shells Under External Pressure—A Numerical Study

by Neda Fazlalipour

2023, Lecture notes in civil engineering

Structural applications of composite materials are used in various structures of the oil and gas industry, water supply and sewage systems and a wide range of industries, such as marine, aerospace, and military industries. This paper aims... more

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Développement en dynamique d'un élément fini multicouche avec interfaces imparfaites

by F. Lebon

2023, hal.inria.fr

-Un élément fini de type layer-wise, une cinématique par couche, est proposé ici. Ce modèle comporte 5n champs cinématiques pour un multicouche à n couches. Cet article a pour but de présenter les récents développement de MPFEAP qui... more

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Influence of fiber type and the layer thickness on the stress distribution in composite pipe

by Jerzy Kaleta

2023

In this work authors presented distribution of circumferential stress in wound composite structures made from different layers. The cylindrical shape specimens were made from layers which have different elastic moduli. Manufactured... more

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Comparison of microstructure, toughness, mechanical properties and work hardening of titanium/TiO2 and titanium/SiC composites manufactured by accumulative roll bonding (ARB) process

by Mohammad Reza Toroghinejad

2023, Ceramics International

Comparison of microstructure, toughness, mechanical properties and work hardening of titanium/TiO 2 and titanium/SiC composites manufactured by accumulative roll bonding (ARB) process, Ceramics International,

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Comparison between elastic properties of theoretical, computational method and experimental results for filament wound composite pipes

by Andrea Corvi

2023, Journal of The Brazilian Society of Mechanical Sciences and Engineering

Some researchers have analyzed the shear stresses induced by tensile stress acting on a pipe and the correla- tion of these stresses with the torsional stress, internal pres- sure, and circumferential stress in pipes wound at +45° [23] or the behavior of pipes wound at +54.7° with differ- ent wall thicknesses [24].

Fig. 3 a Cross section of the strands. b Detail of strands separation and matrix Hu et al. [25] conducted a study that is somewhat similar to that presented here. However, they only considered pipes wound at 4 not utilize + 55°, and their finite-element analysis (FEA) did a parametric model that considers the raw mate- rials individually.

The theoretical analysis was conducted using the well- known modified RM (mRM) and CLT approaches. First,

Fig. 6 a Stress—strain curve for each specimen. b Mean for all SPs +50°

Fig. 7 a Stress—strain curve for each specimen. b Mean for all SPs of +52.5° The parametric assembly was developed through SOLIDWORKS® [40], as shown in Fig. 2a—d. Here, a par- allelogram cross section envelope was used to account for the hexagonal distribution of the dry filaments forming one composite roving-epoxy bundle. The mechanical and physical properties of each constit- uent material, i.e., the fiber strands and polymer, were input individually into the simulation tool [39], and the envelope

Fig. 8 a Stress—strain curve for each specimen. b Mean for all SPs 55° where ¢; = maximum absolute value of strain intensity achieved. where ||uPree | is the equivalent slip, which can be predicted for any given sub-step during the iteration process [42], and uw is equivalent slip rate at a specific iteration number. Additionally, 7; ; is the unitary vector in the slip direction, P is the contact normal pressure, ju is the friction coefficient calculated as t; = u;P + b(i = 1,2), t is the shear stress, and 4, is the displacement due to the shear effect with respect to the plane under consideration.

Fig. 9 Geometry used to calculate the normal loading of the bundles, by winding angle

Fig. 10 a Strain in direction 1. b Strain in direction 2. ¢ Total elongation (50°)

Fig. 11 a Strain in direction 1. b Strain in direction 2. ¢ Total elongation (52.5°) where or) = resultant transversely stress for specific wind- ing angle, o, = axial stress, considering the Y-axis as the The fibers subjected to tensile stress had a strong ten- dency to straighten, especially with large displacements, inducing rotational moments around the local X-axis, i.e., transverse to the winding path. Because the X-axis passes through the wall in the direction tangential to the wind- ing path, when the interlacing prevents the layers from moving (Fig. 9), localized failure occurs once the limit of rupture is reached. The failure then propagates through- out the laminate, leading to the collapse of the bundle interfaces.

Fig. 13 Strains in overlapping points between two consecutive bun- dles due to axial loading

Fig. 12 a Strain in direction 1. b Strain in direction 2. ¢ Total elongation (55°)

Fig. 15 Interlaminar stress effects (traction and compression) on the layers

Fig. 14 a Strains from FEA and tests for +50°. b Strains from FEA and tests for +52.5°. ¢ Strains from FEA and tests for 55°. d Strains from FEA for each angular variation

Fig. 16 a Compared values of E,, for RMm versus CLT, and b Tests versus FEA, for all typologies with the mean and the SD

Fig. 17 a Compared values of E,, for RMm versus CLT, and b Tests versus FEA, for all typologies with the mean and the SD

Fig. 18 a Compared values of G,, for RMm versus CLT, and b Tests versus FEA, for all typologies with the mean and the SD

Fig. 19 a Values of ¢,, for Tests versus FEA, for all typologies with the mean and the SD. b Values of ¢,, for Tests versus FEA, for all typologies with the mean and the SD

Table 2 Fiber ratio according to the Table 1 W,, averaged weight fiber ratio, V;,. Averaged volumetric fiber ratio

Table 3 Total number of paths to complete one layer as a function of the mandrel radius

Table 1 Density according to the experimental results Table 4 Elastic properties found through the mRM

Table 5 Elastic properties found through CLT subjected to biaxial compression [11]. In another study, several theoretical mental results obta ament winding at 4 pression and intern models were compared with the experi- ined for specimens manufactured by fil- t55° and then, subjected to biaxial com- al pressure tests [12].

Table 6 Material properties used as the input data for simulation

Table 8 A comparison of the mechanical properties obtained through all analyses This research was supported by the “Brazilian Federal Agency for the Support and Evaluation of Graduate Educa- tion (CAPES)” of the Ministry of Education of Brazil.

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Failure analysis of biocomposite sandwich pipe under internal pressure – Application for high pressure gas transportation pipelines MEDGAZ

by Abdelkader HOCINE

2023, International Journal of Pressure Vessels and Piping

In this paper, analytical and 3D numerical models are developed to investigate the mechanical behavior of sandwich pipe under internal pressure loading. The suggested models provide an exact solution for stresses, strains and displacement... more

Fig. 9. The evolution of radial displacement distributions versus R of Seq 1.

Fig. 10. The evolution of (a) Axial strain, (b) Hoop strain and (c) Radial strain distributions versus R of Seq 1. 5. Conclusion

Fig. 11. Variations of TSAI-WU criterion versus internal pressure for various layer counts.

Fig. 12. The evolution of hoop stress versus hoop and axial strains.

Comparison of glass fiber and natural fibers. Table 1

Material properties of epoxy in the UD isotropic frame. Table 3

Material properties of Jute/epoxy, PALF/epoxy and glass/Epoxy in the UD orthotropic frame.

Fig. 8. The evolution of shear stress distributions of the three composites versus R of Seq 1.

Fig. 1. Geometry of the sandwich pipe and wall stress components.

The general stress-strain relationship for each k-component exposec to axisymmetric thermo-mechanical loading [69] is shown below:

Fig. 2. The meshing element used for finite element models. In the current study, two types of bio-skin material based on jute and pineapple leaf fibers compared to glass fibers were carried out. The skin materials characteristics are shown in Table 2. The core epoxy is shown in Table 3. The used layered skin stacking sequences are listed in Table 4.

Fig. 3. The sandwich pipe structure. (a) The geometry, (b) the mesh, (c) boundary conditions, and (d) loading of the numerical model.

Fig. 4. Analysis of mesh convergence for finite elements of hoop stress distri- butions versus R. Stacking sequences of sandwich pipe parts with Epoxy core.

Fig. 5. Comparison of analytical and numerical results of Jute/epoxy. (a) Radial displacement, (b) Hoop stress and (c) Axial stress distributions versus R.

Fig. 6. The evolution of Hoop stress distribution for the sandwich pipe parts (inner, outer skins and the core) through thickness.

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Compression Behavior of Pa-12 Pipes Under Large Displacements

by Mechanical Engineering Crimson Publishers

2023, Crimson Publishers

Polyamide (PA) pipes are being increasingly employed in fluid distribution networks. Most of these pipes is used in underground networks, where overloads can cause large deflections. Excessive displacement can lead to product failure and... more

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Novosti iz struke: Posjet studenata Drvnotehnološkog odsjeka Elgradu i Eggerovoj izložbi

by Silvana Prekrat

2023

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Effect of Process Parameters on Thermal and Mechanical Properties of Filament Found Polymer-Based Composites Pipes

by Vineta Srebrenkoska

2023, Polymers

The aim of this study was to investigate the mechanical and thermal properties of composite pipes based on epoxy resin and glass fibers produced by filament winding (FW) technology. Epoxy resins are widely used polymers in FW composite... more

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Experimental and Analytical Investigation of Seismic Bridge-Abutment Interaction in a Curved Highway Bridge

by Joseph Wieser

2023

Report No. CCEER-15-05Seat-type bridge abutments are most commonly used to support the end spans of curved highway bridges. This type of abutment is often selected to eliminate unbalanced stresses in the superstructure under service... more

Fig. 2. Experimental device dedicated to the positioning of specimens.

Fig. 3. Stress state in cylindrical part of hybrid solution. where H’ represents the slope of the hardening law and Q is given by equation (8), where

Fig. 7. TSAI-WU criterion values according to the pressure. Fig. 4. Hoop and axial strains versus hoop stress during sizing pressure on Seq1:[+50]3. Fig. 6. Von Mises stress in the liner from [12] and from the analytical model.

Fig. 5. Hoop and axial strains versus hoop stress during sizing pressure on Seq3: [+60]3.

Fig. 8. Hoop and axial strain evolution according to the hoop stress for the three sequences.

Fig. 11. Hoop and axial strains according the hoop stress for Seq2. In order to assess the strength of the composite, the Tsai-Wu riterion is introduced:

Fig. 10. Hoop and axial strains according the hoop stress for Seq1.

Elastic properties and rupture parameters. Table 2

Loading test-tubes. Stacking sequences. Table 4 Table 3

oO, Carried out; X, not carried out. Considering an anisotropic plastic flow associated with a pref- erential orientation of the internal microstructure, the Hill criterion is used to define the plastic yield function:

Compared results between analytical and numerical procedure. Table 5

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Responsive Video format for adaptive streaming

by Joby George

2023, International Journal for Scientific Research and Development

The increasing use of digital video has put into perspective the storage requirements for a large number of video files. Different qualities of videos are available and each of these requires different storage areas. Different variety of... more

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Energy Release Rate for a New Simplified Modelisation of Laminates Analyse de taux de restitution d’énergie par un modèle simplifié pour un quadricouche en traction fissuré à l’interface entre 2 couches

by Armelle Chabot

2023, Comptes- rendus aux 12ème Journées Nationales sur les Composites (JNC12), ENS de Cachan

The aim of this paper is to establish a delamination criterion of laminates for a new simplified model (Chabot, 97) (Chabot et Ehrlacher, 98). We calculate energy release rates using the example of tension in a cracked (θ1,θ2)s composite... more

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Critère d'initiation de délaminage dans les stratifiés

by RUI PEDRO CARREIRA

2023, Comptes Rendus de l'Académie des Sciences - Series IIB - Mechanics-Physics-Astronomy

R&urn& A partir d'un modkle multiparticulaire de matiriaux multicouches original qui permet de calculer analytiquement les efforts de cisaillement et d'arrachement au niveau des interfaces d'un empilement quelcouque, les auteurs proposent... more

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Un modèle de stratifiés

by RUI PEDRO CARREIRA

2023, Comptes Rendus de l'Académie des Sciences - Series IIB - Mechanics

Un modèle multiparticulaire appelé M4-5n est proposé pour l'étude des matériaux multicouches présentant des déformations élastique et anélastiques dans les couches et des discontinuités des déplacements aux interfaces entre les couches.... more

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Critère d'initiation de délaminage dans les stratifiés

by Alberto Diaz

2023, Comptes Rendus de l'Académie des Sciences - Series IIB - Mechanics-Physics-Astronomy

R&urn& A partir d'un modkle multiparticulaire de matiriaux multicouches original qui permet de calculer analytiquement les efforts de cisaillement et d'arrachement au niveau des interfaces d'un empilement quelcouque, les auteurs proposent... more

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Un modèle de stratifiés

by Alberto Diaz

2023, Comptes Rendus de l'Académie des Sciences - Series IIB - Mechanics

Un modèle multiparticulaire appelé M4-5n est proposé pour l'étude des matériaux multicouches présentant des déformations élastique et anélastiques dans les couches et des discontinuités des déplacements aux interfaces entre les couches.... more

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Special Issue Page 116-120

by DR.Rajkumar Rakesh

2023

ARTICLE INFO Due to advantages of high stiffness and low strength to weight ratio composite materials are widely used in space applications.Some applications undergoes thermal load which causes to generation of thermal stresses. This... more

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Optimal Design of Cylindrical Steel/Composite Hybrid Structures for Gun Barrel Applications

by Jerome Tzeng

2023

Advances in composites design and manufacturing have increased the feasibility of the use of composites into gun tube designs that enable weight reduction, shift the center of gravity and increase the overall natural frequency. In recent... more

Required composite thickness as a function of steel thickness to maintain the steel hoop stresses at a constant value with an internal pressure of 17ksi. (0.53 inch baseline barrel thickness) Figure 6.

The geometry is defined in the cylindrical x-o-r coordinate system as shown in Figure 1. Since only axisymmetric loading is considered, the stresses, strains and displacements are independent of the circumferential coordinate 8. Attention is focused on the response of the cylinder away from the ends, and therefore the stresses and strains are independent of the axial coordinate x. Figure 1. Definition of the Coordinate axes.

Flow Chart for the filament winding model. The constitutive behavior of each layer is determined by a rotational transformation of elastic constants of that layer. The ply by ply strains are then found and summed to find the total cylinder stresses and strains. A flowchart of the program methodology is shown in Figure 2 helow TNDetailse of these formulations are found in Fduliee et a] [5].

In this work, the CCDS (a graphical user interface of the plane deformation model) was developed to aid in optimal design and analysis of composite hybrid cylinders. Additional features of CCDS include a barrel profiler used to design entire composite overwrapped tubes based on variation in internal pressures and temperature along the length of the barrel, a number of common failure models for anisotropic structural analysis, and a model to predict the dynamic strain critical velocity based on effective tube stiffness and density [16]. Figure 3. CCDS Composite Cylinder Design Software (Part of the CDS Suite at UD-CCM)

Figure 4 (b) Total radial, hoop and axial stresses for a 0.5” [0/90] E-Glass Epoxy composite overwrap with an internal pressure of 65ksi and AT of -273°F.

Figure 5. Required composite thickness as a function of steel thickness to maintain the steel hoop stresses at a constant value with an internal pressure of 65ksi. (1.4 inch baseline barrel thickness) optimal ratio based on pressure, autofrettage conditions and whether a CTE mismatch causes separation between composite and steel liner.

Plot of radial stresses for a 0.5 inch steel barrel being wrapped with 0.25” [90], at -50°F with zero tension (105mm barrel, 0.5 inch steel, 0.5 inch wrap) composites are lighter than the glass fiber composite. The problem with wrapping steel witl these materials is the substantial CTE mismatch that can lead to separation at low temperatures The -50°F service temperature requirement for this barrel dictates the upper bound of allowable radial tensile stresses between the composite and steel. Figure 7 is a plot of radial stresses for < 0.5 inch steel barrel being wrapped with 0.25 inch [90], at -50°F with no tension and show: significant tensile stresses between bore and overwrap which can lead to separa ion. Thi: represents the worst case scenario for separation as it corresponds to the highest AT between the process temperature and operating temperature without internal pressure from firing. T his can be overcome either by winding under high tension to compensate for this mismatch or by winding off axis to reduce the effective CTE mismatch. Current filament winders are limi amount of tension that can be provided during winding but work is ongoing in deve ted in the oping the next generation of high tension machines. For the first generation design we consider < combination of both as a method to minimize these radial stresses.

percentage of approximately sixty percent. The E-glass fiber rovings were impregnated witl twenty-three percent resin by weight also resulting in a fiber volume percentage of sixty percent Figures 11 (a-c) shows various stages of this barrel being wrapped at their plant. Figures 11a-c Hybrid Barrel being manufactured at Spenser Composites.

Figure 12 (a) Strain Measurements and CCDS Predictions at the 76 inch location on the 105mm tube with increasing pressure. The finished barrel was sent to Benét laboratories for static pressure testing. Strain gages were mounted on the composite overwrap at 5 different locations along the length of the barrel. The barrel was then pressure tested to 5ksi in ksi increments. Figures 12a and 12b are plots of strain measurements and CCDS model predictions for each pressure at locations 76” inch and 116 inch from the rear face of the tube (RFT). These results also matched the FEA model predictions conducted at Benét labs. In summary, CCDS model predictions were within 2% of all strain and FEA data, successfully demonstrating the accuracy of this program for hybrid tube desicn.

Figure 12 (b) Strain Measurements and CCDS Predictions at the 116 inch location on the 105mm tube with increasing pressure.

Figures 13a-b. 105mm Hybrid Barrel being tested at Aberdeen Proving Grounds. In July 2003 the hybrid tube was test fired at the Aberdeen Proving Grounds. The cannon was fired in both direct (0° elevation) and indirect (30° elevation) fire modes with a mix of kinetic energy simulator and cargo type rounds. Figures 13a and 13b shows the cannon firing in these modes. In the indirect picture, the round can actually be seen in the upper left corner. In total, 11 rounds were fired at pressures ranging from 138 MPa (20 ksi) to 552 MPa (80 ksi).

Figure 14. Surface strain at different locations during firing RFT, along with CCDS model predictions at these points. Once again, good agreement was obtained between model predictions and experimental test data. Conclusions and Summary

Figure 5 is a plot of required composite thickness as a function of steel thickness for the three difference composite overwraps to maintain the steel hoop stresses at a constant value with an internal pressure of 65ksi. The bore is autofrettaged with the plastic radius remaining at a constant ratio of 50% bore thickness. For the E-glass overwrap the required composite thickness tO maintain constant stress in the steel increases dramatically with a small reduction in steel wall thickness. The IM7 and Hy-Bor composite performs better but still reaches a limiting thickness where additional overwrap does not help in reducing the baseline steel hoop stress. The reason for this behavior is attributed to the lower stiffness in the composite radial direction that reduces translation of stress to the composite hoop plies. tT: ~~ £ 2s. _ Ff eq ..hmhlUUlmlc tg tC stl Cite perl Cr] .. ft th. «2h. nt...) £e nl wwii 2d dns. Lowes. Mechanical Properties for materials used in this study.

Table. 2 Comparison of baseline steel and composite overwrap tubes. Tube Manufacture and Testing.

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Finite Element Analysis of Liquefied Ammonia Tank for Mobility Vehicles Employing Polymers and Composites

by Hari Pramono

2023, Energies

Hydrogen has attracted global attention as a clean secondary energy source and has numerous possible applications, including fuel for vehicles. To store the hydrogen effectively, ammonia is considered promising due to high hydrogen... more

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Algorithme mortier pour des problèmes de contact en grandes déformations

by achraf kallel

2023, Le Centre pour la Communication Scientifique Directe - HAL - memSIC

For the simulation of contact problems with the finite element method we usually use the NTS (Node-To-Segment) formulation for transmitting contact constraints from one body to another. The use of the NTS method involves a loss of... more

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Performance of Nano-Filler Reinforced Composite Overwrap System to Repair Damaged Pipelines Subjected to Quasi-static and Impact Loading

by aanchna sharma

2023, Journal of Failure Analysis and Prevention

Nano-filler strengthened fiber reinforced polymer-based composite repair systems are recently being used as a promising solution for repair and rehabilitation of transmission pipelines. To increase the efficiency of pipeline repair system... more

Pipelines are subjected to various types of static and impact loading in their life span. Therefore, in order to use these composites as an overwrap to repair the defects in the

Fig. 3. Quasi-static Indentation Test Setup pipelines, it is very important to characterize their mechanical behavior. To do so, quasi-static and dynamic impact tests were conducted on samples with varying percentage of nano-silica. Drop weight impact test and the burst test were performed on the repaired pipelines using optimized combination of the nano filler reinforced com- posites which outperformed among the others.

percentage of nano-silica (0, 1, 3, and 5%) were tested. The

absorbing capability and failure modes of nano-compos- ites. This test was performed on Universal Testing Machine (UTM), UTE-40 using an ogival shaped steel projectile of 12.3 gm mass and a diameter of 11.6 mm. In order to maintain the same boundary conditions, the same fixture was used for static and dynamic test. The setup used for this test is shown in Fig. 3 The projectile was fixed to the UTM and the load was applied until the projectile’s shank portion completely penetrated the target. Load corre- sponding to the penetration depth of projectile and the maximum deflection was recorded and plotted. This pro- cess was repeated for the laminates with different nano- silica content.

Fig. 5 Schematic diagram of the drop weight pipe impact test setup

Table 1 Mechanical properties of GFRP composites with and without NS Mechanical properties of the GFRP composites with and without nano-silica are reported in Table 1. It was observed that the tensile strength increases with the increase in the percentage of nano-silica but beyond | wt.%, the rate of increase was marginal (Fig. 7). A similar trend was observed in the case of tensile modulus also where an increment of ~ 25% was observed at | wt.% NS. Beyond 1 wt.% NS, increment was not very high because

Fig. 7 Variation of tensile strength with increasing percentage of nano-silica

Fig. 9 Damaged area at the back side of laminates when impacted at 60 m/s (a) NS 0%, (b) NS 1%, (c) NS 3%, and (d) NS 5% Fig. 8 Load-—displacement plot for varying percentage of nano-silica

For samples impacted at 60 m/s, the maximum energy absorption was observed corresponding to lwt.% NS reinforced polymer composite. But in the case of 90 m/s,

Fig. 10 Damaged area (after analyzing using ImageJ software) at the back side of laminates when impacted at 90 m/s (a) NS 0%, (b) NS 1%, (c) NS 3% and (d) NS 5%

Fig. 11 Repaired specimen after drop weight impact the energy at which the sample was tested is equal to the tota stuc velo energy absorbed by the laminate, as the projectile got k within the laminate which led to zero residual city. From the visual inspection, laminate was observed to have undergone failure modes like matrix crac king, delamination and fiber breakage. Presence of nano-silica leads to more active crack arresting mechanism and of t sam plays an important role by inhibiting the further growth he crack tip. Ballistic impact test results indicate a higher energy absorption corresponding to | wt.% NS and sion ami ple. In case of impact loading, energy absorption of aminates depends on the combined effect of both, matrix fiber. Energy was dissipated in different modes of ailure when the laminates were subjected to impact at two different velocities. A localized damage was observed at the point of impact and its vicinity during the impact of the projectile into the target specimen which led to compres- in the front face and tension in the back face of the nate. This damage of the laminates results in the strain

Fig. 12 Failed specimen after burst test (without drop weight impact)

Fig. 13 Failed specimen after burst test (with drop weight impact test)

Table 2 Stiffness and energy for laminates as obtained in the quasi- static indentation test

Table 3 Kinetic energy absorbance of the laminates at both the velocities

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Tensile behaviour of multilayer knitted fabric composites with different stacking configuration

by Yanzhong Zhang

2023, Applied Composite Materials

In this paper, multilayer plain weft knitted glass fabric reinforced epoxy composite laminates with different stacking configurations, i.e., [0 • ] 4 , [0 • / ± 45 • /0 • ], [0 • /90 • /90 • /0 • ] and [90 • ] 4 , were investigated... more

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Investigation of interlayer hybridization effect on burst pressure performance of composite overwrapped pressure vessels with load-sharing metallic liner

by H.Seçil Artem

2023, Journal of Composite Materials

In this study, multi-layered composite overwrapped pressure vessels for high-pressure gaseous storage were designed, modeled by finite element method and manufactured by filament winding technique. 34CrMo4 steel was selected as a... more

Figure |. The geometry of the metallic liner (dimensions are in mm).

Figure 2. The winding of (a) a helical layer and (b) a hoop layer over the metallic liner by the filament winding equipment.

Figure 3. (a) The schematic illustration of strain gage rosette positions on the pressure vessels and (b) a photograph of the hydrostatic test specimen before testing.

Figure 4. A schematic illustration of COPV configurations: (a) GF COPV and (b) hybrid COPY, featuring thickness variations due to filament winding manufacturing at the front dome section.

Figure 5. Thickness and angle deviations through the axial distance of the COPV. equation (1), where o is the effective stress and ¢ is the total elastic strain

Figure 7. |/16 sectioned 3D model of typical COPV. Figure 6. Boundary conditions for COPYs (a) left view (b) front view.

Figure 8. (a) Steel liner, (b) glass fiber COPVs, (c) hybrid fiber COPVs after burst pressure testing

Figure 10. A comparison of experimental and FEA prediction of axial strain values of the glass fiber and hybrid COPY at (a) fror (TI), (b) central (T2), and (c) back (T3) cylindrical section positions.

Figure I1. The radial deformation vs. internal pressure curves of pressure vessels, obtained from FEA.

Figure 12. The axial deformation vs. internal pressure curves of pressure vessels, obtained from FEA.

Figure 13. The maximum equivalent stress of the liner vs. internal pressure curves, obtained from FEA.

Figure 14. The equivalent stress vs. axial distance along the inner surface of the liner at (a) 500 bar and (b) 700 bar

Figure 15. A comparison of the maximum equivalent stress vs. internal pressure at the outermost glass/epoxy layer for both types of COPVs.

Figure 16. The comparison of failure indices of hoop plies of both COPV types near burst.

*The detailed orientation of hybrid vessels is given in Figure 4(b). Table |. Configuration and final dimensions of steel liners and manufactured COPVs.

Table 2. Orthotropic elastic properties and stress limits of glass and carbon fiber reinforced epoxy-based composites and isotropic properties of the steel liner. in order to validate the boundary conditions of the reduced 3D model. It was seen that the displacements in critical regions for both models showed a negligible difference (in the order of 10~-° mm displacement). in contact with the testing apparatus, were set as fixed faces (fixed face A and B).

fable 3. Failure modes with corresponding Hashin failure criteria and material property degradation (MPDG) constants.*7>*

Table 4. The experimental test results and numerical predictions of the burst pressure values.

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Effect of Constituent Shell Thickness on Burst Pressure of Composite Overwrapped Pressure Vessel

by Sabeel Ahmed K

2022

In this paper, the effect of thickness of the liner and composite on the burst pressure and deformation of composite over wrapped pressure vessel under fluid pressure has been investigated by finite element method. Low carbon steel... more

Figure 1 Burst pressure versus winding angle

2.2.5 Procedure For all metal (only liner) pressure vessel, 3-noded triangular shell element whereas for COPV and all composite pressure vessel,4-noded quadrilateral shell element were used to generate the finite element model except at the vicinity of the defect, where 3-noded triangular shell element was used. Finite element meshed models for liner and COPV are shown in figures 2 and 3 respectively. For boundary conditions, both ends of the cylinder are considered as fixed. The step-by-step procedure adopted for the prediction of burst pressure by finite element analysis is given in flow chart (Figure 4). ANSYS Composite PrepPost(ACP), an add-on module is exclusively designed for modeling of layered composite structures. In the present work, ACP(Pre) is used for the analysis of COPV.

The deformation of the pressure vessel recorded by the software for the incremental internal pressure are plotted for different types of pressure vessels namely., all metal, all composite and COPV by varying the wall thickness. Typical plots obtained from the software are shown in Figure 5.

Figure 5(a) reveal that, the deformation of all metal (liner) pressure vessel is negligible at the beginning followed by significant deformation for small incremental pressure as indicated by the plateau region. The pressure versus deformation plots for all composite and COPV pressure vessels showed almost identical trend with linear increase in the deformation with the incremental increase in the pressure (Figures 5(b), 5(c) and 5(d)). Firstly, we calculate the burst pressure theoretically for all the cases and mention some more value in the FE analysis. In FE analysis the software wil take incremental value of pressure for every time step and the pressure versus deformation graph will plotted. At a particular pressure when the elements are deformed plastically and fails to withstand that pressure and that pressure is burst pressure and very next iteration software will take the maximum value of pressure that we mentioned in the software that’s why the change of slope in the curve will occurs. The pressure corresponding to sudden rise and change in slope of the curve is the indication of burst pressure. At this point, the pressure vessel loses its capability to resist deformation.

Figure 6 Deformation corresponding to burst pressure

pressure. The deformation of COPV with liner thickness of 1mm and composite thickness of 5 mm is 12 mm which is 58.38% lesser than all metal pressure vessel. Lesser deformation is the indication of greater stiffness of COPV which is a measure of better resistance to deformation. The deformed pressure vessel along with the value of maximum deformation as obtained from ANSYS is shown in figure 7 for all metal pressure vessel and COPV with 1 mm liner and 5 mm composite wall thickness. 2.5 Conclusions

Table 3 Properties of Carbon/Epoxy Composite

Table 4 Geometry of the Cylindrical Shell 2.2.3 Winding angle

Table 5 Correlation between Theoretical and Numerically Predicted burst pressure

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Chernov S. Back from oblivion after 200 years // Science in Russia. N 3-4, May-August 1993. P. 88-93

by Sergey Chernov

2022

The article publishes the results of the excavations of the Dubensky Shavykin Monastery conducted by the expedition of the Institute of Archaeology of the Russian Academy of Sciences in 1989 and 1990. Traces of the monastery remain on the... more

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Structural performance analysis of cross-laminated timber-bamboo (CLTB)

by Jorge Daniel de Melo Moura

2022, BioResources

Construction systems based on cross-laminated timber (CLT) have versatility in material development and are an interesting alternative for construction. This study evaluated the structural performance of cross-laminated timber-bamboo... more

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Multilayer Laminate

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