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1

Impact of fiber metal laminates - literature research

Lisowski B.

Mechanics and Mechanical Engineering

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2018

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Vol. 22, nr 4

1355--1370

EN

The paper refers the general idea of composite materials especially Fiber Metal Laminates (FMLs) with respect to low-velocity impact incidents. This phenomenon was characterized by basic parameters and energy dissipation mechanisms. Further considerations are matched with analytical procedures with reference to linearized spring-mass models, impact characteristics divided into energy correlations (global flexure, delamination, tensile fracture and petaling absorbed energies) and set of motion second order differential equations. Experimental tests were based on analytical solutions for different types of FML - GLARE type plates and were held in accordance to ASTM standards. The structure model reveals plenty of dependences related to strain rate effect, deflection represented by the correlations among plate and intender deformation, separate flexure characteristics for aluminium and composite, contact definition based on intender end-radius shape stress analysis supported by FSDT, von Karman strains as well as CLT. Failure criteria were conformed to layers specifications with respect to von Misses stress-strain criterion for aluminium matched with Tsai-Hill or Puck criterion for unidirectional laminate. At the final stage numerical simulation were made in FEM programs such as ABAQUS and ANSYS. Future prospects were based on the experiments held over 3D-fiberglass (3DFG) FMLs with magnesium alloy layers which covers more favorable mechanical properties than FMLs.

2

Detection of damages in hybrid composite plates with the use of elastic waves generated by PZT active sensors

Barski M., Pająk P.

Journal of KONES

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2017

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Vol. 24, No. 2

17--24

EN

The presented article is devoted to the problem of detection and localization of damages occurring in components of structures, which are made of hybrid composite materials. The subject of the work is a square plate consisting of a single layer made of aluminum alloy and several layers made of glass fibres (glass fabric) and epoxy resin. On the surface, which is made of composite, 12 piezoelectric elements are installed. These elements sequentially, one by one, generates a signal that is further recorded by the remaining piezoelectric elements. Picked up signal for the selected pair of activator – sensor is compared with the reference signal. The reference signal corresponds to the intact structure. This kind of approach is known as the pitch – catch configuration. In situations when the signal obtained for interrogated structure and reference one differs significantly, this may indicate that a damage exists between the activator and the sensor. Next, taking into account the information obtained from the other sensors, it is possible not only to detect but also to determine the approximate location of the flaw and to estimate its size. In order to visualize the obtained results, an especially dedicated software is developed according to the algorithms available in the literature – probability ellipse. Several computer simulations of wave propagation are performed using the finite element method. The proposed procedure is also tested experimentally. The presented approach makes it possible to detect both single and multiple damages.

3

Development Of Multistitched Three-Dimensional (3D) Nanocomposite And Evaluation Of Its Mechanical And Impact Properties

Bilisik K., Ozdemir H., Kaya G.

Autex Research Journal

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2017

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Vol. 17, no. 3

238--249

EN

Multistitched three-dimensional (3D) woven E-glass/polyester/nanosilica composite (MNS) was developed. Its mechanical and impact performances were characterized for particular end-use applications. It was found that the warp-weft directional tensile strength and modulus of MNS structure were higher than those of the off-axis directions. In addition, there was not a big difference between warp and weft directional bending and short beam strengths of MNS structure. The MNS structure had a small damaged area under low velocity impact load. The failure was confined at a narrow area because of multistitching and nanomaterial and resulted in the catastrophic fiber breakages in the normal direction of the applied load of the structure. The results from the study indicated that the multistitching and the addition of nanosilica in the composite structure improved its damage tolerance.

4

Stiffness behavior of hybrid laminated composites with surface crack

Güneş A., Şahin Ö. A.

Archives of Materials Science and Engineering

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2016

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Vol. 80, nr 2

49--52

EN

Purpose: The purpose of this paper investigates to stiffness behavior of hybrid laminated composites with surface crack. Design/methodology/approach: Hybrid laminated composites has 18 layers and 90x25 mm size with two different layers line up. The low velocity impact test of hybrid laminated composites carried on 3 m/sec with a/t=0.4 and a/c=0.4 surface crack parameters. Findings: The results are presented as the change of force-time and force-displacement graphs. As a result of this study, effects of stacking sequence on hybrid composite plates were analysed. Research limitations/implications: The research of stiffness behavior or dynamic response of hybrid laminated composites can contribute to developing new composite materials. Practical implications: These hybrid laminated composites materials could be used for different aviation areas. Originality/value: This paper is based on studies from Selçuk University and all the experiments and results were conducted by me.

5

Effect of surface crack depth on hybrid laminated composites

Güneş A., Şahin Ö. S.

Archives of Materials Science and Engineering

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2016

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Vol. 82, nr 1

38--41

EN

Purpose: The purpose of this paper researches to effect of different surface crack depth on hibrid laminated composites under low velocity impact forces. Design/methodology/approach: Hybrid laminated composites have 90x25 mm size and 18 layers with two different stacking sequence. Low velocity impact test of hybrid laminated composites with surface crack have been investigated with different a/t surface crack parameters and 3 m/sec velocity. Findings: The results are presented force-time and energy-time graphs than effects of different crack parameters were observed. As a result of this study, effects of surface crack depth on hybrid composite plates were analysed. Research limitations/implications: The research of dynamic behavior of hybrid laminated composites with surface crack can contribute to literature searches. Practical implications: These hybrid laminated composites materials could be used for different aviation areas. Originality/value: This paper is based on studies from Selçuk University and all the experiments and results were conducted by me.

6

A study on low velocity impact response of FGM rectangular plates with 3D elasticity based graded finite element modeling

Asemi K., Jedari Salami S.

Journal of Theoretical and Applied Mechanics

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2015

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Vol. 53 nr 4

859—872

EN

Low velocity impact behavior of rectangular plates made of functionally graded materials (FGMs) based on three-dimensional theory of elasticity is studied in this paper. The modified Hertz contact law, which is appropriate for graded materials, is employed. On the basis of the principle of minimum potential energy and the Rayleigh Ritz method, the graded finite element modeling is applied. Solution of the nonlinear resulted system of equations in the time domain is accomplished via an iterative numerical procedure based each time on Newmark’s integration method. The effects of various involved parameters, such as the graded property profile, projectile velocity and projectile density on time histories of contact force, lateral deflection and normal stresses are investigated in detail. To present efficiency of the present work, several numerical examples are included. The main novelty of the present research, which has not been reported in literature, is considering the difference of lateral deflection through the thickness of the FGM plate due to analyzing three-dimensional elasticity of the plate.

7

Low Velocity Impact Behaviour of Aramid and UHMWPE Composites

Karahan M., Yildirim K.

Fibres & Textiles in Eastern Europe

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2015

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Vol. 23, no. 3 (111)

97--105

EN

The most popular method to produce composites for ballistic applications is to use aramid and ultra high molecular weight polyethylene (UHMWPE) fibers as reinforcement materials in different matrices. The composite materials used in this type of application, especially those used as armoring materials for explosions, are subjected to a very high level of energy. In this study, the effect of the reinforcement material type and cross-plied condition of reinforcement were examined using high-level impact tests. The impact tests were performed at low speed but high energy, and thus the behaviour of the composite materials that were exposed to high-level impact energy could be examined. According to the results, the UD aramid composite produced the best results with respect to high-level impact tests. In addition, mass optimisation could be achieved without the loss of the high-level impact energy by preparing a hybrid composite with UD UHMWPE and UD aramid fibers.

PL

Powszechną metodą produkcji kompozytów dla zastosowań balistycznych jest użycie jako wzmocnienia włókien aramidowych oraz włókien polietylenowych o super wysokim ciężarze cząsteczkowym i różnych materiałach matrycy. Materiały kompozytowe stosowane w tego typu rozwiązaniach, specjalnie te stosowane jako materiał wzmacniający w przypadku eksplozji są poddawane testom o bardzo wysokim poziomie energii. W przedstawionej pracy badano efekty zastosowania różnego typu materiałów wzmacniających i ich konfiguracji w strukturze. Badania prowadzono stosując testy udarowe o bardzo wysokiej energii lecz małej prędkości udaru. Dzięki temu można było sprawdzić zachowanie różnych zastosowanych materiałów. W efekcie stwierdzono, że najlepsze wyniki uzyskuje się używając włókna aramidowe. Dodatkowo można było przeprowadzić optymalizacje masy poprzez przygotowanie kompozytów hybrydowych.

8

Experimental Investigation on the Impact Behaviour of Composite Laminate

Azzam A, Li W

Fibres & Textiles in Eastern Europe

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2015

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Vol. 23, no. 1 (109)

77--84

EN

The impact response of a composite laminate structure was investigated by subjecting several stacking sequences of a composite laminate structure to low velocity impact loading using a Drop-Weight Machine (CEAST 9350 drop tower) and three-point bending using an electronic universal tester (Type: WDW-20) machine. The air-coupled ultrasonic C-scan technique (NAUT21) was selected in order to characterise the impact damage size, delamination, flaw detection, and damage in composite laminate structures. The failure processes of damaged specimens for impact energy (5 J) were evaluated by comparing load-displacement curves and images of damaged samples taken from impacted sides through a C-scan.

PL

Badano odpowiedź na udar struktury laminatów kompozytowych. Zastosowano kilka sekwencji udarów charakteryzujących się małą prędkością. Stosowano specjalną maszynę umożliwiającą opadanie obciążenia (wieża udarowa). Zginanie następowało w systemie trzech punktów podparcia. Zastosowano sprzężoną technikę ultradzwiękowego skanowania dla scharakteryzowania wielkości uszkodzeń w wyniku udaru, delaminację warstw i zmiany strukturalne. Dla scharakteryzowania uszkodzeń materiału badawczego powstałych przy energii udaru 5J wykorzystano porównanie wykresów obciążenie-przesunięcie i zdjęć uszkodzonych próbek.