Materials Today: Proceedings xxx (xxxx) xxx
Contents lists available at ScienceDirect
Materials Today: Proceedings
journal homepage: www.elsevier.com/locate/matpr
Comparative study of quasi-static indentation (QSI) response of
composites used in maritime transport
Houcine Zniker a,⇑, Mohammed Khalil El Kouifat b, Ikram Feddal c, Said Bouzakraoui a, Bennaceur Ouaki b
a
Laboratory of Advanced Materials and Process Engineering, Ibn Tofaïl University, Kenitra, Morocco
The National Higher School of Mining of Rabat (ENSMR), Rabat, Morocco
c
Department of Industrial and Civil Sciences and Technologies, Abdelmalek Essaadi Tetouan, Morocco
b
a r t i c l e
i n f o
Article history:
Available online xxxx
Keywords:
Quasi-static indentation
Impact energy absorption
Damage
Composite materials
a b s t r a c t
The objective of this experimental investigation is to study the behavior of quasi-static indentation (QSI)
of two composite panels (sandwich composite with PVC core -GFRP laminated composite) used in maritime transport, in order to develop a basic understanding of their behavior under the dynamic loading of
low-velocity impact. To do so, a series of low-velocity quasi-static perforation tests were performed until
the entire penetration, the force–displacement curves, the absorbed energy, and the resultant damage
under this quasi-static loading were compared and analysed. The experimental results show that the
absorbed penetration energy and the induced damage of the 8 mm laminates for the sandwich composites are almost the same. It was found that the effect of PVC core on quasi-static indentation behavior for
sandwich composite is almost negligible, due to its low penetration resistance.
Copyright Ó 2023 Elsevier Ltd. All rights reserved.
Selection and peer-review under responsibility of the scientific committee of the Fifth edition of the
International Conference on Materials & Environmental Science.
1. Introduction
Due to the several benefits of the composites over traditional
materials (steel, aluminum, and wood), such as resistance to corrosion and rot, better strength-to-weight ratio, and design flexibility
for usage in complicated geometries. Sandwich and laminated
fiber-reinforced composite materials are commonly employed in
the marine transport industry, such as fast ferries, pleasure boats,
racing yachts, navy and coastguard patrol ships, and fishing and
work boats [1]. However, these types of these materials are susceptible to impact loading that can happen during their in-service life.
The resultant damage can seriously affect the stiffness and strength
of the structure [2–4]. Therefore, the behavior of composite structures under low-velocity impact have become an important area of
research for a long time.
The impact loading develops complex damage mechanisms, and
the damage accumulation process is very complicated. Consequently, it is crucial to understand the damage progress sequence
in composite materials under low-velocity impact loading. An
impact test is typically conducted over a short period of time, mak-
⇑ Corresponding author.
E-mail address: Zniker.houcine@gmail.com (H. Zniker).
ing it difficult to monitor the damage sequence. Some authors have
turned to the quasi-static perforation method to overtake these
difficulties [5–7]. QSI is much simpler when compared to lowvelocity impact (LVI): where there is an absence of oscillations
and low acquisition rates suffice. According to Nettles and Douglas
[8], the QSI damage can be detected without difficulty, and the
deflection of the composite plate and the maximum transverse
load during this test can be measured directly with great precision.
The quasi-static test is considered the energy absorption ability of
composites when they are subjected to the axial loads without
dynamic and rate effect. These tests are described as the input
design of impact resistance under low-velocity impact which can
provide valuable information about composites.
Numerous studies have been conducted about the damage
mechanisms and failure of composite materials under quasistatic loading. Yan et al. [9] carried out a series of quasi-static penetration and low-velocity impact tests, they performed an examination of the relationship between the impact energy (and quasistatic indentation load) and the damaged surface. The results
showed that the quasi-static test and the low-velocity impact tests
give almost the same results, which shows that the quasi-static
penetration test can be used to simulate low-velocity impact testing. Burt et al. [10] invertigated the quasi-static perforation behavior of laminated composites with a fiber-reinforced hybrid. The
https://doi.org/10.1016/j.matpr.2022.09.488
2214-7853/Copyright Ó 2023 Elsevier Ltd. All rights reserved.
Selection and peer-review under responsibility of the scientific committee of the Fifth edition of the International Conference on Materials & Environmental Science.
Please cite this article as: H. Zniker, M. Khalil El Kouifat, I. Feddal et al., Comparative study of quasi-static indentation (QSI) response of composites used in
maritime transport, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2022.09.488
H. Zniker, M. Khalil El Kouifat, I. Feddal et al.
Materials Today: Proceedings xxx (xxxx) xxx
2.2. Experimental investigation
results indicate that fiber stacking sequence and fiber types
strongly influence on the failure mechanism of hybrid samples.
Prince Jeya Lal et al. [11] studied the effect of impregnation
epoxy-fiberglass matrix composite laminates with nanosilica as a
secondary reinforcement on quasi-static properties. They found
that the use of up to 0.75% by weight of nanosilica significantly
improved energy absorption properties by 53.97% during quasistatic indentation tests. They concluded that 0.75 wt% nosilica
can be used as a good material for secondary reinforcement in an
epoxy laminate composite. In another study, Prince Jeya Lal et al.
[12] also found that using nanosilica as a secondary reinforcement
in epoxy/GFRP composite laminates improves compressive
strength, stiffness, and damage resistance during low-velocity
impact tests.
The present work has aimed to investigate experimentally the
quasi-static indentation behavior, energy absorption capability,
and the damage mechanisms of two composite panels (sandwich
composite with PVC core -GFRP laminated composite) used in maritime transport. Therefore, the quasi-static penetration tests were
carried out until the entire penetration for two types of composites
used in maritime, and the induced damages were analysed.
A quasi-static penetration test (QSI) was performed on laminate
and sandwich panels using the universal machine (model
LR30KPlus). The specimen was prepared (see Fig. 2) and fixed
between his two steel beams with 45 mm square holes on the sides
using a hemispherical steel indenter with a diameter of 12.7 mm, a
perforation load is applied centrally according to ASTM D 6264-98
[13] with a displacement speed of 2 mm/min. The tests were finished after the entire penetration.
3. Results and discussion
Load and absorbed energy diagram versus displacement and
schematic curves for laminate (4 mm and 8 mm) and sandwich
specimens during quasi-static testing are shown in Fig. 3a and b
in order to investigate and compare the mechanical response of
sandwich and laminate composites. By using the trapezoidal
numerical integration method, the absorbed energy was determined from the area under the force–displacement graph.
Fig. 3b shows the curves obtained for three tests for the composite laminate, the quasi-static response of these materials is
established according to three stages. In the first region (I), the
laminated composite has an elastic and linear behavior where
the indentation force increases approximately linearly until the
peak load is reached because the sample damage mechanisms
are not yet initiated. In the second region (II), the stress drops
slightly due to matrix crack initiation, the stress increases slightly
due to fiber resistance. In the third stage (III), the force gradually
decreases until the whole penetration. This is the result of the failure of laminated specimens due to delamination, cracking matrix,
and fiber breakage.
Fig. 3b shows also the curves obtained for three tests for the
sandwich composite. During the three stages mentioned in the
curve, the impactor penetrates the skin of the sandwich by realizing the same quasi-static behavior observed for laminated composite in in the same figure (Fig. 3b). After the third stage, the
penetrator started penetrating evenly the PVC core until its full
penetration (region IV), then the penetrator started to load the
lower skin (region V) and produced the same quasi-static behavior
as shown in stages I, II and III.
Fig. 4 presents the comparison of the peak load and the total
indentation energy based on the experimental results indicated
in Fig. 3 for the three types of investigated composites.
The results indicate that the sandwich and 8 mm laminate composite (consisting of two 4 mm laminate skins) have nearly identical total indentation energies. This demonstrates that the effect of
2. Materials and methods
2.1. Materials
This experimental investigation concerns two types of composite panels (PVC core sandwich composite – GFRP laminated composite) used in real maritime transport structures. The first type
of composite is made by a cross-laminate (0/90), composed of
polyester as matrix support and unidirectional fiberglass fabric as
a reinforcing constituent. This composite has an average volume
fraction of 50%.and a total thickness of 8 mm (see Fig. 1b). The second type of composite is a typical sandwich fabricated using 4 mm
thick panels of the first composite as skins (See Fig. 1a and c). PVC
foam with a thickness of 20 mm and a density of 80 kg/m3 was
used as the sandwich core material. The total thickness of the
PVC core and the two laminated skins which constitute sandwich
composites is 28 mm (see Fig. 1c). For comparison reasons we also
chose composite laminated specimens with a thickness of 4 mm,
this is the thickness of the sandwich skin and half the thickness
of the 8 mm laminated composite (see Fig. 1a). The laminated composite and skin sandwich have been prepared by hand layup and
cured under vacuum bagging under atmospheric pressure at room
temperature.
Fig. 1. Composites materials: a: 4 mm laminate; b: 8 mm laminate; c: sandwich composite.
2
Materials Today: Proceedings xxx (xxxx) xxx
H. Zniker, M. Khalil El Kouifat, I. Feddal et al.
Fig. 2. Tested specimens during quasi-static indentation: (a) before test; (b) after test.
Fig. 3. Quasi-static indentation test results: (a) Load and energy versus displacement for laminates (4 mm, 8 mm) and sandwich composites; (b) schematic curves.
observed by other authors [14] for glass fiber reinforced PP Granules (0/90) under the quasi-static test perforation test. Moreover,
it has been observed that the damaged areas mostly show high
delamination near the puncture area as shown in Fig. 5. These
delaminations were also observed by scanning electron microscope (SEM) analysis for sandwich skins and laminated composites, as shown in Fig. 6.
PVC core on energy absorption for sandwiches is almost negligible.
The total indentation energy for 8 mm laminate is approximately
2.8 higher than that of 4 mm laminated composites. This is due
to the higher structural rigidity linked to the greater thickness,
which improves the absorbed elastic energy. The results also show
that the maximum load is influenced only by the variation of the
thickness of the laminates.
Fig. 5 shows examples of damaged areas caused by entire penetration. A comparison of the top damaged faces reveals that the
largest damaged area is observed for the 4 mm laminate, due to
its low thickness. The sandwich composites and 8 mm laminate
tested have surface damages that are nearly identical in shape
and surface on the front and rear sides, confirming that the effect
of PVC core on quasi-static indentation behavior for sandwich
composite is almost negligible.
Furthermore, the orientation of the damage occurs in the direction of the fibers (0° and 90°), and similar results have been
4. Conclusion
In this study, quasi-static tests were performed on two types of
composite panels (PVC core sandwich composite and GFRP laminated composite) used in real maritime transport structures. The
load–displacement and energy-displacement curves. Based on
the experimental investigations, it was found that the 8 mm laminate and the sandwich composite (consisting of two 4 mm laminate skins) have nearly identical total indentation energies. This
3
H. Zniker, M. Khalil El Kouifat, I. Feddal et al.
Materials Today: Proceedings xxx (xxxx) xxx
Fig. 4. Comparison of Quasi-static indentation test results.
Fig. 5. Pictures of damaged specimens: (a) 4 mm laminates, (b) sandwich composite, and (c) 8 mm laminates.
demonstrates that the effect of PVC core on quasi-static indentation behavior for sandwich composite is almost negligible, due to
its low penetration resistance. Therefore, laminated composite
panels are better suited for constructing components exposed to
quasi-static penetrating loads compared to sandwich composites.
Data availability
No data was used for the research described in the article.
Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared
to influence the work reported in this paper.
References
Fig. 6. Examples of damage observed on sandwich skins and laminated composites
established by Scanning Electron Microscopy (SEM).
[1] E. Natarajan, L.I. Freitas, M.S. Santhosh, K. Markandan, A.A. Majeed Al-Talib, C.
S. Hassan, Experimental and numerical analysis on suitability of S-Glass4
Materials Today: Proceedings xxx (xxxx) xxx
H. Zniker, M. Khalil El Kouifat, I. Feddal et al.
[2]
[3]
[4]
[5]
[6]
[7]
[8] A.T. Nettles, M.J. Douglas, A comparison of quasi-static indentation to lowvelocity impact, vol. NASA/TP-20, no. August. 2000.
[9] Y. Li, X. An, X. Yi, Comparison with Low-Velocity Impact and QuasistaticIndentation Testing of Foam Core Sandwich Composites, Int. J. Appl.
Phys. Math. 2 (1) (2012) 058–062, https://doi.org/10.7763/ijapm.2012.v2.54.
[10] M. Bulut, A. Erkliğ, The investigation of quasi-static indentation effect on
laminated hybrid composite plates, Mech. Mater. 117 (2018) 225–234.
[11] N. Sio, P. Jeya, L. Lazar, R. Sengottuvelu, E. Natarajan, Assessments of Secondary
Reinforcement of Epoxy Matrix-Glass Fibre Composite Laminates through,
2018, doi: 10.3390/ma11112186.
[12] L.P.J. Lal, S. Ramesh, S. Parasuraman, E. Natarajan, I. Elamvazuthi,
‘‘Compression after Impact Behaviour and Failure Analysis of NanosilicaToughened Thin Epoxy/GFRP Composite Laminates, Materials (Basel) 12(19)
(2019), doi: 10.3390/ma12193057.
[13] ASTM D 6264-98(04), Standard test fiber-reinforced polymer-matrix
composite to concentrated quasi-static indentation force, ASTM Int. 98
(2004) 98–100, https://doi.org/10.1520/D6264_D6264M-17.
[14] M. Mahdad, A.A. Saada, I. Belaidi, A. Mokhtari, A. Benidir, Damage Modelling in
Thermoplastic Laminates Reinforced with Steel and Glass Fibres under QuasiStatic Indentation Loading at Low-Velocity, Adv. Compos. Lett. 27 (6) (2018).
Carbon fiber reinforced polymer composites for submarine hull, Def. Technol.
(2022), https://doi.org/10.1016/J.DT.2022.06.003.
S.Z.H. Shah, S. Karuppanan, P.S.M. Megat-Yusoff, Z. Sajid, Impact resistance and
damage tolerance of fiber reinforced composites: A review, Compos. Struct.
217 (2019) 100–121, https://doi.org/10.1016/j.compstruct.2019.03.021.
M. Basha, A. Wagih, A. Melaibari, G. Lubineau, M.A. Eltaher, On the impact
damage resistance and tolerance improvement of hybrid CFRP/Kevlar
sandwich composites, Microporous Mesoporous Mater. 333 (2022), https://
doi.org/10.1016/j.micromeso.2022.111732 111732.
H. Zniker, B. Ouaki, S. Bouzakraoui, M. EbnTouhami, H. Mezouara, Energy
absorption and damage characterization of GFRP laminated and PVC-foam
sandwich composites under repeated impacts with reduced energies and
quasi-static indentation, Case Stud. Constr. Mater. 16 (2022) e00844.
X. Zhang, F. Bianchi, H. Liu, Predicting low-velocity impact damage in
composites by a quasi-static load model with cohesive interface elements,
Aeronaut. J. (1968) 116 (1186) (2012) 1367–1381.
Y. Aoki, H. Suemasu, T. Ishikawa, Damage propagation in CFRP laminates
subjected to low velocity impact and static indentation, Adv. Compos. Mater.
16 (1) (2007) 45–61.
M. Damghani, N. Ersoy, M. Piorkowski, A. Murphy, Experimental evaluation of
residual tensile strength of hybrid composite aerospace materials after low
velocity impact, Compos. Part B Eng. 179 (2019) 107537.
5