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1

Investigation of the influence of debonding shapes and debonding locations on vibration behavior of sandwich structure

Demircioğlu Ufuk, Çakır Mutlu Tarık

Composites Theory and Practice

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2024

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R. 24, nr 1

39--48

EN

Sandwich structures are employed in many different fields including automobile, marine, and aircraft structures. However, debonding may take place at the core-face sheet interface, reducing the stiffness of the structure. Debonding may occur for a variety of reasons, including initial manufacturing faults, changes in service loads, tool drops, and foreign object impacts. It is critical to comprehend how debonding zones impact the vibration of sandwich structures because decreases in the natural frequencies (NF) could lead to a structure vibrating at resonance and lead to structural failure. This paper investigates the influence of debonding shapes and debonding locations on the free-vibration behavior of sandwich structures. Different sandwich structures that have varied debonding shapes at various locations are modeled using COMSOL MULTIPHYSICS. Debonding is modeled by using the CZM model. Validation studies were performed to validate the current study. After the validation study, free vibration analysis of all the sandwich structures was performed and the first six NF were obtained from the simulations. The results show the influence of the debonding shapes and debonding locations on the NF of the sandwich structures. From the results, it was observed that both the debonding shapes and debonding locations significantly change the NF of the sandwich structures. The debonding shapes cause a reduction and an increase depending on the debonding location. It was also revealed that both debonding shapes and debonding locations have a significant effect on the vibration behavior of sandwich structures. Using this method, the debonding shape and location, delamination shape, and location can be predicted using machine learning algorithms. This study includes free vibration analysis of sandwich structures with different debonding shapes and locations, and the results show that natural frequencies change depending on the debonding shapes and locations. This information can be implemented in machine learning for use in the field of damage detection and utilized to predict the shape and location of delamination in sandwich structures.

2

Numerical Study of the Energy Absorption Performance of 3D Printed Sandwich Structures

Estrada Quirino, Zubrzycki Jarosław, Reynoso-Jardón Elva, Szwedowicz Dariusz, Rodriguez-Mendez Alejandro, Marchewka Magdalena, Vergara-Vazquez Julio, Bastarrachea Aztlán, Silva Jesús M.

Advances in Science and Technology. Research Journal

|

2023

|

Vol. 17, no 5

153--162

EN

Nowadays, Fused Deposition Modeling (FDM) is a powerful tool for manufacturing complex components, due to its customizability, low cost, accessibility, and fast prototyping time. It is an alternative for creating thin-walled structures, as it allows for novel designs. This article focuses on the design and numerical evaluation of 3D printed sandwich structures for energy absorption applications. For this purpose, five structures of Acrylonitrile Butadiene Styrene (ABS) were designed. To ensure optimal performance, the 3D printing parameters were optimized based on the corresponding literature. The structures had cores based on polygonal and cell arrangements. The effects of cross-section and mass on energy absorption were analyzed, and parameters such as energy absorption, peak load, mean force, and crush force efficiency (CFE) were determined during the study. The structures were assessed by out-of-plane compression tests. The numerical analysis was executed using Abaqus finite element software. Results showed that the energy absorption performance is primarily determined by the geometry and density of the structures. The best performance was found for a circular cellular structure, with a CFE of 0.884.

3

Testing the attenuation capabilities of ballistic shields made using 3D printing

Wierzbicka Karolina, Paszula Józef, Gieleta Roman, Komorek Zenon

Materiały Wysokoenergetyczne

|

2022

|

T. 14

58--75

EN

The paper describes a study of the blast wave energy absorption capabilities of sandwich ballistic shields. A comparative study of multilayer structures containing cores with different elementary cell shapes in their structure was performed. Energy-absorbing layers of different types of polymers were made. Tests of static and dynamic properties of the ballistic shield layers were carried out. The attenuation capabilities of these shields were determined by measuring the force acting on the base substrate of the shield.

PL

W pracy zaprojektowano i wykonano osłony balistyczne typu sandwich oraz przeprowadzono badania zdolności absorbowania energii fali podmuchowej. Przeprowadzono porównawcze badania struktur wielowarstwowych zawierających w swojej strukturze rdzenie o różnych kształtach komórek elementarnych. W badaniach przygotowano warstwy wykonane z różnych typów materiałów. Przeprowadzono badania właściwości statycznych i dynamicznych zaprojektowanych warstw osłon balistycznych. Zdolność tłumiącą wytypowanych osłon określano poprzez pomiar siły działającej na podstawę osłony.

4

Free vibration and buckling analyses of FG porous sandwich curved microbeams in thermal environment under magnetic field based on modified couple stress theory

Arshid Ehsan, Arshid Hossein, Amir Saeed, Mousavi S. Behnam

Archives of Civil and Mechanical Engineering

|

2021

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Vol. 21, no. 1

89--111

EN

Porous sandwich structures include different numbers of layers and are capable of demonstrating higher values of strength to weight ratio in comparison with traditional sandwich structures. Free vibration and mechanical buckling responses of a three-layered curved microbeam was investigated under the Lorentz magnetic load in the current study. A viscoelastic substrate was considered and the effect of the thermal environment on its mechanical properties was assessed. The core was composed of the functionally graded porous materials whose properties changed across the thickness based on some given functions. The face sheets were FG-carbon nanotube-reinforced composites and the influence of the placement of CNTs was evaluated on the behavior of the faces. Using the extended rule of mixture, their effective properties were determined. Modified couple stress theory was used to predict the results in the micro-dimension. While the governing equations were derived based on the higher order shear deformation theory and energy method, and mathematically solved via Navier’s method. The results were validated with the previously published works, considering the effects of various parameters. As comprehensively explained in the results section, natural frequencies and critical buckling loads were reduced by enhancing the central opening angle. Moreover, an increase in the porosity coefficient declined the mentioned values, but increasing the CNTs content showed the opposite effect. The outcomes of this study may help in the design and manufacturing of various equipment using such smart structures, making high stiffness to weight ratios more accessible.

5

Change of the thermal properties of footwear packages by using of different polymer-based materials

Serweta Wioleta, Wójcik Justyna, Szałek Beata, Matusiak Małgorzata

Inżynieria Materiałowa

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2020

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Vol. 41, nr 2

14--19

EN

In this paper authors focused on the thermal properties of polymer materials used as footwear linings. The research concerned on the two types textiles: with two-dimensional and spacer structures. The monitoring of thermal conductivity property through the upper footwear materials is very important in order to create the qualitative and quantitative evaluation of them and make the recommendations to use of them in a footwear applications. In the next step of research, the two-layered packages were created and then the previously mentioned properties were measured. The optimal packages due to the thermal resistance and absorption were found based also on the other hygienic measures, like water vapour permeability and absorption.

PL

Zbadano właściwości przewodnictwa cieplnego polimerowych materiałów obuwniczych płaskich i przestrzennych. Materiały te są powszechnie stosowane w roli wyściółek i podszewek. Monitorowanie zjawiska przewodnictwa cieplnego materiałów cholewkowych jest bardzo ważnym czynni- kiem w ocenie jakościowej i ilościowej materiałów rekomendowanych do wykorzystania w produkcji cholewek. W kolejnym etapie na bazie wcześniej zbadanych materiałów pojedynczych utworzono pakiety dwuwarstwowe i wytypowano te, które w najbardziej optymalny sposób zabezpieczały stopę przed utratą ciepła, a jednocześnie pozwalały na zachowanie bardzo dobrych właściwości higienicznych pod kątem absorpcji i przepuszczalności pary wodnej.

6

Mechanical performances of metal-polymer sandwich structures with 3D-printed lattice cores subjected to bending load

Liu Zhaobing, Chen Hantang, Xing Shuaiqi

Archives of Civil and Mechanical Engineering

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2020

|

Vol. 20, no. 3

368--384

EN

In this article, we propose a new class of metal-polymer architected sandwich structures that exhibit different mechanical behaviors. These lightweight sandwich structures have been made of aluminum face sheets and 3D-printed lattice cores with 2D (Bi-grid, Tri-grid, Quadri-grid and Kagome-grid) and 3D (face-centered cubic-like and body-centered cubic-like) topologies. Finite element simulation and experimental tests were carried out to evaluate mechanical performances of the proposed sandwich structures under quasi-static three-point bending load. Specifically, the damage-tolerant capability, energy absorption and failure mechanisms of these sandwich structures were investigated and evaluated through a combination of analytical, numerical and experimental methods. It is found that sandwich structures with 3D face and body-centered cubic-like cores can provide more excellent flexural stiffness, strength and energy absorption performance. These enhanced mechanical features could be further explained by a so-called ‘Stress Propagation’ mechanism through finite element analysis (FEA) that can facilitate sandwich structures with 3D cores, especially body-centered cubic-like one, to transfer bending loads from central lattice units across neighboring ones more efficiently than 2D cores. Furthermore, core cracking is the main failure mode for the proposed sandwich structures, which is primarily caused and dominated by bending-induced tensile stress followed by shear stress. It is worth mentioning that our findings provide new insights into the design of novel lightweight sandwich composites with tailored mechanical properties, which can benefit a wide variety of high-performance applications.

7

Numerical simulations of sandwich structures under lateral compression

Estrada Quirino, Szwedowicz Dariusz, Vergara Julio C., Solis José, Paredes Miguel A., Wiebe Lara, Silva Jesús M.

Applied Computer Science

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2019

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Vol. 15, no 2

31--41

EN

The current paper analyzes the effect of the cross-section on the energy absorption capabilities of sandwich structures under compressive loads. For this purpose, several cross-section including triangular, square, hexagonal and circular shapes were analyzed using Abaqus software. According to the results the hexagonal shape is the most favorable cross-section to increase the crashworthiness performance of the structures up to 700% of CFE with respect to the square arrangement.

8

Transient forced vibration response analysis of heterogeneous sandwich circular plates under viscoelastic boundary support

Alipour M. M.

Archives of Civil and Mechanical Engineering

|

2018

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Vol. 18, no. 1

12--31

EN

For the first time the transient bending analysis of a sandwich plate with viscoelastic boundary support is investigated in this study. Viscoelastic support consists of two sets of translational springs and dashpots connected in parallel along the in-plane and transverse directions. The sandwich plate is fabricated from heterogeneous face sheets where the material properties of each face sheets are assumed to be varied continuously in the radial direction according to a power-law function. Variations of the material properties of each face sheets are monitored by eight distinct inhomogeneity parameters. Therefore, the solution procedure may be used for a wide range of the practical problems. In order to investigate the effects of viscoelastic edge supports on the transient response of sandwich plate a wide range of the stiffness and damping coefficients of the edge supports in the in-plane and transverse directions are applied. Results of sandwich plates with the classical edge conditions as some special cases of the elastic/viscoelastic supports are compared with those extracted from the ABAQUS software based on the 3D theory of elasticity. The comparisons show that even for relatively complicated cases, there is a good agreement between the results.

9

Composite GFRP u-shaped footbridge

Chróścielewski J., Miśkiewicz M., Pyrzowski Ł., Wilde K.

Polish Maritime Research

|

2017

|

S 1

25--31

EN

The paper presents proposals for the use of glass fiber reinforced polymer composites for the construction of engineering objects, known and commonly used in the shipbuilding industry. An example of a pedestrian footbridge was used in this case, which, despite the considerable thickness of the structural material, was made using infusion technology in one production cycle. The designed and produced footbridge span is durable, dynamically resistant, incombustible, easy to install and maintain, resistant to weather conditions and also aesthetically interesting. For footbridge production environmentally friendly PET foam core may be used. It may come from recycling of used plastic packages and which is produced with less energy consumption process and much less CO2 emission. The load bearing part of the structure (skin) is made of polymer laminate reinforced with glass fabrics (GFRP).

10

Characterization of quasi-static behavior of honeycomb core sandwich structures

Katunin A., John M., Joszko K., Kajzer A.

Modelowanie Inżynierskie

|

2014

|

T. 22, nr 53

78--84

EN

Honeycomb core sandwich composite structures gained their popularity in aircraft, aerospace, automotive and naval industries mainly due to their superior flexural stiffness and very low mass, which cause that their application in engineering constructions becomes very attractive. Since they contain core and face sheets made of different materials with different properties their behavior under quasi-static loading is highly nonlinear and the forcedisplacement response contains characteristic zones caused by various mechanical phenomena. The characterization of such behavior under tensile and bending loading as well as characterization of failure mechanisms accompanied with quasi-static loading is the main goal of this paper. Obtained experimental results and their analysis allow for better understanding of occurred phenomena in such structures, which can be helpful during modeling of elements made of such sandwich composites as well as prediction of their behavior under various loading conditions.

PL

Kompozyty przekładkowe z rdzeniem o strukturze plastra miodu zyskały swoją popularność w przemyśle lotniczym, kosmicznym, samochodowym oraz okrętowym głównie dzięki swojej wyjątkowej sztywności oraz bardzo niskiej masie, co spowodowało że ich wykorzystanie w konstrukcjach inżynierskich stało się bardzo atrakcyjne. Biorąc pod uwagę fakt, że rdzeń i okładziny wykonane są z różnych materiałów o różnych właściwościach zachowanie tych struktur pod wpływem obciążeń quasi-statycznych jest wysoce nieliniowe, a odpowiedź siła-przemieszczenie zawiera charakterystyczne obszary spowodowane różnymi zjawiskami mechanicznymi. Charakteryzacja takiego zachowania podczas obciążeń rozciągających i zginających oraz mechanizmów zniszczenia towarzyszących obciążeniom quasi-statycznym jest głównym celem tej pracy. Otrzymane wyniki eksperymentalne i ich analiza pozwalają na lepsze zrozumienie zachodzących zjawisk w takich strukturach, co może być przydatne przy modelowaniu elementów wykonanych z kompozytów przekładkowych, jak również predykcji ich zachowania przy różnych warunkach obciążenia.

11

Influence of longitudinal edge profiling in sandwich panels on interpretation of experimental results

Chuda-Kowalska M.

Prace Naukowe Instytutu Matematyki i Informatyki Politechniki Częstochowskiej

|

2012

|

Vol. 11, nr 4

19-27

EN

Panels with a polyurethane foam core and thin metal facings are considered. Behaviour of these structures depends strongly on the shear rigidity. The recommended methods of identification of the Kirchhoff modulus of the core material GC give different results depending on the used sample. The FEM analysis are performed and the effects of longitudinal edge profiling are presented and discussed.

12

Poliuretanowo-stalowe konstrukcje sandwiczowe typu SIP

Datta J., Surawska E., Witkiewicz W.

Przemysł Chemiczny

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2008

|

T. 87, nr 11

1115-1117

13

Experimental support for numerical simulations of energy absorbing structures

Ochelski S., Gotowicki P.

Journal of KONES

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2008

|

Vol. 15, No. 1

183-217

EN

This paper presents experimental investigations of mechanical properties of materials used in the absorbing energy structures. Numerous experimental investigations are essential to develop a reliable numerical model of composite structures absorbing the impact energy. This model should correctly describe the dissipation of kinetic impact energy in the progressive crush process. Mechanical properties of composite materials like elastic modulus, strength, failure strains with influence of anisotropic properties are obtained experimentally. Different strength hypotheses are used for fibrous composites. The investigations on the complex stress state allow determining which of these theories describes the composite best. It was proved that both the matrix type and the structure of the composite have a very large influence on the SEA (Specific Energy Absorption), in particular on their crack propagation resistance. The dependence between the energy absorbed by a single energy absorbing element and a fragment of the structure absorbing the impact energy was discussed. Friction forces play the important role in the progressive crush of composites and they should be taken into account in developing a valid numerical model. Some authors state that the friction forces absorb 40% of the impact energy. The influence of failure strain rates on the absorbing energy capability, which is not clearly defined in the literature about composite structures, was also discussed.

14

Porównanie energochłonności konstrukcji przekładkowych typu sandwicz z wypełnieniem oraz cienkościennych struktur falistych

Ochelski S., Bogusz P.

Biuletyn Wojskowej Akademii Technicznej

|

2008

|

Vol. 57, nr 1

145-157

PL

W pracy opisano badania eksperymentalne konstrukcji energochłonnych. Dokonano porównania wyników zdolności pochłaniania energii uderzenia struktur typu sandwicz z wypełnieniem z tworzywa spienionego oraz cienkościennych konstrukcji energochłonnych z rdzeniem z powłoki falistej. Wykonano próbki z użyciem kompozytu epoksydowego wzmocnionego matą szklaną, tkaniną szklaną i tkaniną węglową. Struktury faliste ze wzmocnieniem włóknami węglowymi wykazały najwyższą wartość względnej energii absorpcji.

EN

The work presents experimental studies of energy absorbing structures. The presented investigation covers absorbing impact energy capability results of sandwich structures with a core made of composite plates filled with foamed material (PVC) and composite thin-walled waved constructions. The specimens were made of glass mat, glass fabric, and carbon fabric reinforced with epoxy resin. The waved thin-walled energy absorbing structures reinforced with carbon fabric proved to be the best.

15

FEM strength analysis of sandwich panels for ship structure applications

Augustyniak M., Porembski G.

Polish Maritime Research

|

2006

|

S 1

24-26

EN

This paper presents results of the numerical simulation modelling strength tests of laser-welded, foam-filled steel panels, performed by means of the Finite Element Method (FEM) within the frame of the ASPIS project. In this case application of the FEM makes it possible to significantly lower costs of determination of mechanical properties and optimization of the structure respective to its strength-weight ratio. The entire project as well as the presented calculations are aimed at implementing structures of the kind to shipbuilding industry. Results of the calculations modelling axial compression of panels comply with experiments qualitatively. The entire process of the structure’s compression till its collapse resulting from extensive plastic deformation within its middle zone, was step-by-step examined. Also, critical forces causing instability of the structure were determined. A partial quantitative discrepancy of the calculated reaction forces and those experimentally measured, requires further investigations.

16

Application of steel sandwich panels to hull structure of two-segment inland navigation passenger ship

Szarnik A., Kuryłko A.

Polish Maritime Research

|

2006

|

S 2

85-87

EN

This paper presents a concept of hull structure of novel environment-friendly inland navigation and coastal ships for Polish east-west waterways. In compliance with its assumptions the inland navigation passenger ship is designed in the form of two mutually connected segments : a propulsion segment which contains gastronomy and entertainment infrastructure and crew accommodations and an articulated hotel segment. In this paper attention is focused on solutions of the hotel segment of an innovative structure mainly consisted of steel polyurethane-filled sandwich panels. Similar structural solution is intended for the propulsion segment.

17

Low velocity impact damage in glass / polyester composite sandwich panels

Lendze T., Wojtyra R., Guillaumat L., Biateau C., Imielińska K.

Advances in Materials Science

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2006

|

Vol. 6, nr 1

26-34

EN

Impact resistance of glass/polyester facesheets/PVC foam core sandwich structures was primarily assessed in terms of skin-/core bonding efficiency using two types of adhesives and bonding with uncured resin. Also, the air-coupled ultrasonic C-scan technique was estimated as a means of characterizing impact damage size in sandwich structures. The following observations were made. The impact damage size estimated by visual inspection was much more extensive in all samples, which is due to the C-scan images showing only the overlapping delaminations area directly under the impact site, whereas the visual inspection of the laminate surface and macroscopic observations of the sample section show the extent of the largest, single delamination. The least extensive damage size was found in the two-phase high-density adhesive samples showing also the highest tendency for core cracking. In contrast, the “pinkglue” adhesive, which is low-density due to the presence of the microspheres provides greater local flexibility which prevented core craking.

18

Mechanical properties of a cellular composite: comparison with other structures

Schmitt Y., Pierrot J-L., Arbaout J., Royer F-X.

Archives of Metallurgy and Materials

|

2005

|

Vol. 50, iss. 1

111-117

EN

Bending and crash properties of an original cellular composite based on polystyren cells BOXcell are compared with a polypropylene honeycomb and a thermoplastic foam panel. The panels are covered with different walls.

PL

Przedmiotem pracy jest porównanie własności takich jak gietkość i łamliwość oryginalnego kompozytu komórkowego na bazie komórek poliestyrenu BOXcell z polipropylenem typu plaster miodu i płytą termoplastycznej piany. Porównywane płyty pokryto rożnorodnymi powłokami.

19

Konstrukcje warstwowe w aspekcie bezpieczeństwa biernego

Romanów F.

Zeszyty Naukowe Politechniki Świętokrzyskiej. Mechanika

|

2002

|

Z. 76

97-124

PL

W pracy przedstawione są teoretyczne i doświadczalne podstawy obliczania konstrukcji warstwowych w aspekcie zastosowania ich do budowy nadwozi samochodowych. Wyeksponowano szczególnie te zagadnienia, które mają wpływ na podniesienie komfortu jazdy i bezpieczeństwo bierne. Nadwozia samochodowe w sensie konstrukcyjnym składają się z prętów, belek, płyt, tarcz i powłok. Dlatego przedstawiono najnowsze metody ich obliczania, badania oraz dobór parametrów materialnych i konstrukcyjnych koniecznych w celu zwiększenia energoabsorbcyjności tych elementów podczas zderzenia pojazdów. Wszystkie obliczenia oparte są o najnowsze metody uwzględniające hiperboliczną hipotezę stanu przemieszczeń rdzenia i w zależności od potrzeby, stosuje się geometrycznie liniową lub nieliniową teorię oraz liniowe i nieliniowe związki fizyczne. W ostatnim rozdziale podano zastosowania konstrukcji warstwowych na nadwozia samochodowe oraz ich podzespoły.

EN

In this paper theoretical and experimental basic of calculation of the sandwich structures with respect to their application in car bodies has been presented. Particulary these aspects which affect the increase of the drive comfort and the passive safety were set off. Car bodies in a design sense are composed of rods, beams, plates, discs and coats. Therefore the latest methods of their calculation, researching and selection of material and design parameters required in order to increase energy absorption of these parts during the vehicle hits has been presented. All calculations are based on the latest methods which include hyperbolic hypotheses of the core displacement state and depend on the requirement geometrical linear or nonlinear theory and linear or nonlinear physical relations are applied. In the last chapter examples of the sandwich structures used for car bodies and their sub-assemblies have been shown.