Energy Characteristics and Failure Mechanisms for Textile Spread Tow Thin Ply Thermoplastic Composites under Low-velocity Impact

In this study, low velocity impact behavior of E-glass fiber-reinforced thermoplastic composites repaired by pressing external laminated composite patches was investigated by experimental methods. Thermoplastic composites were manufactured from polypropylene granules with two different fiber contents of 40 wt. % and 60 wt. %. Repaired specimens were prepared by using unidirectional E-glass reinforced polypropylene based thermoplastic prepregs. In order to compare the low velocity impact behavior of the repaired and unrepaired specimens, a number of single impact tests (ranging from energy levels of 10 J to 50 J) were carried out through a drop weight impact test machine with a hemispherical impactor. Low-velocity impact response of the specimens was investigated with cross-examining contact force-deformation curves and damaged specimens. Impact damages occurred in the upside and bottom surfaces of the composites were recorded from the visual inspection and compared for repaired and unrepaired specimens. According to experimental results, bending stiffness and maximum contact force of the specimens having fiber content of 60 wt.% are higher than those of 40 wt.%. Moreover, it was concluded that the patch repaired specimens have achieved a better performance in terms of maximum contact force and absorbed energy compared to the intact specimens.

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Influence of Preload Type on the Low Velocity Impact Response of Glass Fiber Reinforced Thermoplastic Composites

International Polymer Processing ◽

10.3139/217.3893 ◽

2020 ◽

Vol 35 (2) ◽

pp. 193-202

Author(s):

H. Kandas ◽

O. Ozdemir

Keyword(s):

Glass Fiber ◽

Impact Response ◽

Low Velocity Impact ◽

Thermoplastic Composites ◽

Fiber Reinforced ◽

Low Velocity ◽

Velocity Impact ◽

Glass Fiber Reinforced

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Experimental and numerical investigation on the effect of projectile nose shape in low-velocity impact loading on fiber metal laminate panels

Proceedings of the Institution of Mechanical Engineers Part G Journal of Aerospace Engineering ◽

10.1177/0954410018804384 ◽

2018 ◽

Vol 233 (10) ◽

pp. 3665-3679

Author(s):

H Ahmadi ◽

M Ekrami ◽

H Sabouri ◽

M Bayat

Keyword(s):

Numerical Simulation ◽

Failure Mechanisms ◽

Low Velocity Impact ◽

Aluminum Sheet ◽

Low Velocity ◽

Velocity Impact ◽

Conical Indenter ◽

Fiber Metal Laminate ◽

Nose Shape ◽

Fiber Metal

In this paper, low-velocity impact responses of 2/1 GLARE 3 (a commercial type of fiber metal laminate) specimens were studied experimentally and numerically. The effects of indenter's nose shape (flat, conical, and hemispherical) on energy absorption and failure mechanisms were thoroughly investigated. Drop weight testing machine with different impact energies was used for experimental tests and numerical simulation was also carried out. Failure mechanisms, such as delamination, debonding, aluminum sheet rupture, and composite laminate fracture, were discussed by sectioning the tested specimens. The results indicate that maximum and minimum contact force occurred with flat and conical indenters, respectively. Also, the target absorbs the utmost energy under the penetration of flat indenter and least energy during conical indenter perforation. It is depicted that the deflection at the peak load represents the main failure of the panel. Consequently, front aluminum sheet failure is determinant in fiber metal laminate panels impacted by flat and hemispherical indenters where back aluminum sheet is more significant for fiber metal laminate panels impacted by the conical indenter. Numerical simulation verified by experimental results is extended to lower impact weights and more velocities, which are discussed.

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Experimental and Numerical Analysis of Low-Velocity Impact of Carbon Fibre-Based Non-Crimp Fabric Reinforced Thermoplastic Composites

Polymers ◽

10.3390/polym13213642 ◽

2021 ◽

Vol 13 (21) ◽

pp. 3642

Author(s):

Muhammad Ameerul Atrash Mohsin ◽

Lorenzo Iannucci ◽

Emile S. Greenhalgh

Keyword(s):

Finite Element ◽

Carbon Fibre ◽

Energy Levels ◽

Composite Plates ◽

Low Velocity Impact ◽

Thermoplastic Composites ◽

Low Velocity ◽

Velocity Impact ◽

Extent Of Damage ◽

The Impact

There has been a lot of interest in understanding the low-velocity impact (LVI) response of thermoplastic composites. However, little research has focussed on studying the impact behaviour of non-crimp fabric (NCF)-based fibre reinforced thermoplastic composites. The purpose of this study was to evaluate the LVI responses of two types of non-crimp fabric (NCF) carbon fibre reinforced thermoplastic laminated composites that have been considered attractive in the automotive and aerospace industry: (i) T700/polyamide 6.6 (PA6.6) and (ii) T700/polyphenylene sulphide (PPS). Each carbon/thermoplastic type was impacted at three different energy levels (40, 100 and 160 J), which were determined to achieve three degrees of penetrability, i.e., no penetration, partial penetration and full penetration, respectively. Two distinct non-destructive evaluation (NDE) techniques ((i) ultrasonic C-scanning and (ii) X-ray tomography) were used to assess the extent of damage after impact. The laminated composite plates were subjected to an out-of-plane, localised impact using an INSTRON® drop-weight tower with a hemispherical impactor measuring 16 mm in diameter. The time histories of force, deflection and velocity are reported and discussed. A nonlinear finite element model of the LVI phenomenon was developed using a finite element (FE) solver LS-DYNA® and validated against the experimental observations. The extent of damage observed and level of impact energy absorption calculated on both the experiment and FE analysis are compared and discussed.

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