Publications
158 results found
Wan A Hamid WLH, Iannucci L, Robinson P, 2023, Flexural behaviour of 3D-printed carbon fibre composites: Experimental and virtual tests - application to composite adaptive structure, Composites Part C: Open Access, Vol: 10
Flexural properties of 3D-printed carbon fibre (CF) composites are investigated, experimentally and numerically. A series of 3-point bending experimental tests are conducted on CF composite specimens, and a series of 3-point bending virtual tests are simulated in LS-DYNA using a composite modelling approach, which is user defined integration points through the composite thickness. The flexural stress-strain results are compared, and they show good agreement within the elastic region. In the plastic region, the experimental flexural modulus reduces significantly, which remains constant for a certain range of flexural strain, before structural failure. A new hypothesis on the flexural properties of the 3D-printed CF composite is suggested, which is the specimen behaves as two stacks of individual beams, after yielding/delamination. The hypothesis is supported by another series of FE simulations on the composite, modelled as two stacked composite beams, and subjected to 3-point bending load. Then the capability of the composite 3D-printing to manufacture a structure with complex geometries and to manufacture several parts as a single structure, are exploited to fabricate a CF composite corrugated structure with a trailing edge section. The structure which represents an internal structure of a morphing aerofoil is actuated by a NiTi shape memory alloy (SMA) wire with a 1.6% recoverable strain. A trailing edge deflection of 6.0 mm is obtained, which is measured using an IMETRUM optical system. It is reasonably close to the predicted deflection of 7.3 mm shown in the FE simulation, using a newly developed UMAT for SMA-actuation, in an explicit LS-DYNA.
Gouskos D, Iannucci L, 2023, An experimental and numerical study on the translaminar fracture of cross-ply non-crimp fabric composites, ENGINEERING FRACTURE MECHANICS, Vol: 277, ISSN: 0013-7944
Kempesis D, Iannucci L, Ramesh KT, et al., 2022, Micromechanical analysis of high fibre volume fraction polymeric laminates using micrograph-based representative volume element models, Composites Science and Technology, Vol: 229, Pages: 109680-109680, ISSN: 0266-3538
This work develops RVE-based finite element (FE) models to understand how the microstructure of Ultra-High-Molecular-Weight Polyethylene (UHMWPE) composites affects the overall mechanical behaviour of the laminate. The models represent a [0/90] configuration with a random fibre packing sequence through the thickness of each ply, as well as a variation in the cross-sectional shape of the fibres, both obtained from laminate cross section micrograph images. The uncertainty of interface properties and its effects on the overall mechanical response is also investigated. The response of the fibre is assumed to be viscoelastic-plastic and transversely isotropic and the three-dimensional constitutive behaviour is implemented through a user-defined subroutine in the LS-DYNA explicit FE code. Constituent properties are calibrated using experimental results on UHMWPE single fibres and a generic thermoplastic polyurethane resin material. The numerical results generated by the RVE models are validated against experimental results found in the open literature. Special focus was given to the in-plane shear and out-of-plane compression response of UHMWPE laminates. Our results can be used as inputs in a homogenised continuum level model, to express the effect of uncertainties which propagate from the microstructure to the macro-scale response.
Gouskos D, Iannucci L, 2022, A failure model for the analysis of cross-ply Non-Crimp Fabric (NCF) composites under in-plane loading: Experimental and numerical study, Engineering Fracture Mechanics, Vol: 271, Pages: 108575-108575, ISSN: 0013-7944
In the present work, a set of physically-based failure criteria are applied to a cross-ply Non-Crimp Fabric (NCF) composite. The proposed criteria account for the stitch reinforcement and the induced in- and out-of-plane fibre misalignment. A distinction between matrix and fibre failures in tension and compression is introduced, while the in-plane shear non-linear response is directly incorporated to the model as well. The constitutive model is associated with an energy-based damage mechanics method, which consists of five in-plane damage variables per layer level. Within this study, a novel approach to obtain the effective longitudinal stiffness of the composite, as a function of the in- and out-of-plane misalignment, is described. An experimental study characterises the internal structure and the mechanical response of the composite in tension, compression, in-plane shear and Mode I & II interlaminar fractures. In this paper, validation examples for the failure criteria, implemented in Abaqus/Explicit as a VUMAT subroutine, are presented. Tensile, in-plane shear and compressive responses are modelled at a coupon level with continuum shell elements and correlate well with the experimental data. Fibre misalignment, mainly out-of-plane, had a strong influence on the compressive modulus and strength of the composite.
Del Rosso S, Iannucci L, Kempesis D, et al., 2022, Self-heating effect on ultra-high molecular weight polyethylene fibres and composites, Materials and Design, Vol: 220, Pages: 1-12, ISSN: 0264-1275
This paper investigates the self-heating effect observed during testing ultra-high molecular weight polyethylene (UHMWPE) fibres and their composites, in particular Dyneema® SK76 fibres and Dyneema® HB26 laminates. Monotonic and cyclic tests were carried out at strain rates between 0.00833 s−1 and 250 s−1, frequencies up to 20 Hz, and different mean stress, amplitude stress and stress ratios to evaluate the self-heating effect developing in the materials. Measurements of the specimen’s temperature were carried out using a thermochromic liquid crystal paint and an infrared sensor. Experimental results showed that the temperature increased during fibre testing by as much as 13.2 ± 0.2 °C and, even though the maximum temperature was below the melting temperature of the material, melting was observed. Tension-tension cyclic tests showed that the fatigue life of the coupon specimens significantly depended on the testing conditions. In some cases, the measured temperature was as high as 102 ± 1 °C. Depending on the fatigue parameters, the laminates showed two different types of failure modes: mechanical or thermal. Hence, it is important to take into account self-heating effects when designing engineering parts reinforced with UHMWPE fibres.
Yin H, Li Q, Iannucci L, 2022, Meso-scale Finite Element (FE) modelling of biaxial carbon fibre non-crimp-fabric (NCF) based composites under uniaxial tension and in-plane shear, Composite Structures, Vol: 290, Pages: 1-17, ISSN: 0263-8223
Non-crimp-fabrics (NCF) are promising materials in aerospace applications. The complex internal structure of NCF composites could influence the in-plane performances, which needs to be comprehensively studied. The novel three-dimensional (3D) meso-scale repeated unit cell (RUC) models were proposed for biaxial NCF composites based on the Finite Element (FE) method to conduct a systematic parameter study, including layup sequence, out-of-plane tow waviness, resin-rich areas, transverse tow placements and delamination. The meso RUC model could effectively predict the homogenised uniaxial tensile and in-plane shear properties of biaxial NCF composites based on their meso-scale constituent and material properties. A multiscale framework was also developed for biaxial NCF composites. A micromechanical representative volume element (RVE) model provided homogenised mechanical properties for tows, and a macroscopical FE model validated the test results using the homogenised results obtained from meso RUC models. The numerical results were in good agreement with the experiment results. Therefore, the multiscale framework provides an insight into the critical parameters influencing the in-plane properties of NCF composites and an analysis tool for NCF material design.
Falco S, Fogell N, Kasinos S, et al., 2022, Homogenisation of micromechanical modelling results for the evaluation of macroscopic material properties of brittle ceramics, INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES, Vol: 220, ISSN: 0020-7403
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- Citations: 4
Yin H, Iannucci L, 2022, An experimental and finite element investigation of compression-after-impact (CAI) behaviour of biaxial carbon fibre non-crimp-fabric (NCF) based composites, Composite Structures, Vol: 281, ISSN: 0263-8223
The damage mechanisms of biaxial non-crimp-fabric (NCF) reinforced composites with a quasi-isotropic [(45/-45)(90/0)]4s layup subject to low-velocity impact (LVI) and compression-after-impact (CAI) loadings are investigated. Experimental results indicate that fibre compressive failure in the 0° plies controls the peak load during CAI, which is influenced by the out-of-plane transverse deformation of the impacted specimen. The study proposes a novel finite element (FE) model to predict the CAI strength of the NCF specimen. While the number of delaminations in the LVI model is less than the actual number of the multiple delaminations in the test specimen, the same out-of-plane transverse deformation measured by the experiment is still captured. The strength predicted from the subsequent CAI model is in good agreement with the experiment. The study provides a potential numerical design tool for the use of NCF materials in damage-tolerant structures.
Abdullah SIBS, Iannucci L, Greenhalgh ES, et al., 2021, The delamination behaviour of Vectran/Epoxy composites having a novel Non-Crimp Fabric architecture, COMPOSITES PART B-ENGINEERING, Vol: 228, ISSN: 1359-8368
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- Citations: 2
Abdullah SIBS, Iannucci L, Greenhalgh ES, et al., 2021, A Plane-Stress Damage Model for Vectran Laminated Composite, APPLIED COMPOSITE MATERIALS, Vol: 28, Pages: 1255-1276, ISSN: 0929-189X
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- Citations: 2
Kempesis D, Iannucci L, Del Rosso S, et al., 2021, A representative volume element model for ultra-high-molecular-weight-polyethylene composites, Composite Structures, Vol: 262, Pages: 1-11, ISSN: 0263-8223
This paper presents the development of a Representative Volume Element (RVE) for Ultra-high-Molecular-Weight-Polyethylene (UHMWPE) composites. The numerical models were based on the fibrillar nature of UHMWPE fibres, which consist of smaller scale, continuous through-the-length macro-fibrils. A three-dimensional constitutive model for UHMWPE macro-fibrils was developed and implemented in the LS-DYNA explicit finite element (FE) code, through a user-defined subroutine. The proposed transversely isotropic model accounts for viscoelastic effects in the principal direction of the fibre coupled with the continuum damage mechanics approach. Energy dissipation associated with failure was controlled through an objectivity algorithm to provide mesh insensitive solutions. Hill’s yield criterion was used to capture the non-linear response of the fibre in the transverse direction. The RVE was built from macro-fibrils and a Thermoplastic Polyurethane (TPU) resin in order to study the micromechanical response of the polymeric composite laminate. Periodic boundary conditions (PBC) were imposed in the model and a penalty-based cohesive contact algorithm was used to simulate interfibrillar interactions and the interface between the macro-fibrils and the resin. The proposed RVE model provides insight on microscale deformation mechanisms in UHMWPE composites under different loading conditions.
Mohsin M, Iannucci L, Greenhalgh E, 2021, On the dynamic tensile behaviour of thermoplastic composite carbon/polyamide 6.6 using split Hopkinson pressure bar, Materials, Vol: 14, ISSN: 1996-1944
A dynamic tensile experiment was performed on a rectangular specimen of a non-crimp fabric (NCF) thermoplastic composite T700 carbon/polyamide 6.6 specimens using a split Hopkinson pressure (Kolsky) bar (SHPB). The experiment successfully provided useful information on the strain-rate sensitivity of the NCF carbon/thermoplastic material system. The average tensile strength at three varying strain rates: 700, 1400, and 2100/s was calculated and compared to the tensile strength measured from a standardized (quasi-static) procedure. The increase in tensile strength was found to be 3.5, 24.2, and 45.1% at 700, 1400, and 2100/s strain rate, respectively. The experimental findings were used as input parameters for the numerical model developed using a commercial finite element (FE) explicit solver LS-DYNA®. The dynamic FE model was validated against experimental gathering and used to predict the composite system’s behavior in various engineering applications under high strain-rate loading conditions. The SHPB tension test detailed in this study provided the enhanced understanding of the T700/polyamide 6.6 composite material’s behavior under different strain rates and allowed for the prediction of the material’s behavior under real-world, dynamic loading conditions, such as low-velocity and high-velocity impact.
Abdullah SIBS, Iannucci L, Greenhalgh ES, et al., 2021, The impact performance of Vectran/Epoxy composite laminates with a novel non-crimp fabric architecture, COMPOSITE STRUCTURES, Vol: 265, ISSN: 0263-8223
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- Citations: 3
Razavi S, Iannucci L, Smith Greenhalgh E, 2020, A piezo smart‐braid harvester and damper for multifunctional fiber reinforced polymer composites, Energy Technology, Vol: 8, Pages: 1-12, ISSN: 2194-4288
The past decade has seen the rapid development of wearable electronics, wireless sensor networks (WSNs), and self‐powered implantable sensors. However, these devices usually require a continuous source of power supply to operate safely and accurately while having the least reliance on conventional battery systems—due to the recharging/maintenance burdens of batteries. Vibration‐based piezoelectric energy harvesting (PEH) from environment, man‐made machinery, and human body movements seems to be a promising solution. Herein, the first integration of a piezoelectric poly(vinylidene fluoride) (PVDF) yarn‐braid microgenerator into a fiber reinforced polymer composite (FRPC) structure is reported. It is demonstrated that the developed smart composite exhibits multifunctional performances, including simultaneous structural (with ≈10% increased Young's modulus), energy harvesting, and vibration damping (with a damping factor of 125%). The results show that an average output voltage of 3.6 V and a power density of 2.2 mW cm−3 can be achieved at strains below 0.15%, under cyclic loading tests between 1 and 10 Hz. Moreover, noticeable improvements are made in the crystallinity percentage and β‐phase content of as‐received PVDF yarns by, respectively, ≈34% and ≈37%, as a result of the applied coreless radial and axial corona poling techniques.
Hamid WLHWA, Iannucci L, Robinson P, 2020, Finite-element modelling of NiTi shape-memory wires for morphing aerofoils, AERONAUTICAL JOURNAL, Vol: 124, Pages: 1740-1760, ISSN: 0001-9240
Razavi S, 2020, The development of a smart piezo-braid for composite applications
Del Rosso S, Iannucci L, 2020, On the compressive response of polymeric cellular materials, Materials, Vol: 13, ISSN: 1996-1944
This paper presents a series of compression tests performed on a variety of high performance lightweight cellular materials conventionally used in energy absorption applications. Compressive tests were performed over a range of strain rates with a universal testing machine and a single stage gas gun. Experimental results revealed a dependency of the mechanical properties on the polymeric precursor, density, infill topology and strain rates. The dynamic strength of the investigated materials was determined through a material parameter identification study via the finite element (FE) method. Numerical results matched well with the experimental results and revealed a substantial enhancement in the compressive strength of the tested material from quasi-static to dynamic loading regimes by as much as 87%. The strength of 3D printed polymers was superior with respect to the tested polymeric foams. On the other hand, polymeric foams showed higher efficiency and energy absorption ability.
Gouskos D, Iannucci L, 2020, Finite element analysis of non-crimp fabric laminates under compact tension
The present work regards the computational analysis of a triaxial [450/00/-450] non-crimp fabric (NCF) laminate under compact tension (CT) with the use of finite element methods in Dassault Systèmes Abaqus® 2017 commercial software. Specifically, the scope of this study concerns the calculation of the translaminar fracture toughness of the NCF laminate implementing the physically-based failure criterion LaRC05 [1] as a build-in subroutine in Abaqus. The NCF blanket is consisted of three plies in which the material orientations, 450, 00, -450 are modelled explicitly, while at tow level, fibres, resin and stitches are homogenised with the rule of mixtures. The results of the simulation are compared to existing test results [2] and show good correlation at the pure elastic region, while towards crack onset and propagation mean deviation of approximately 12% is observed.
Gouskos D, Iannucci L, 2020, Finite element analysis of non-crimp fabric laminates under compact tension
© CCM 2020 - 18th European Conference on Composite Materials. All rights reserved. The present work regards the computational analysis of a triaxial [450/00/-450] non-crimp fabric (NCF) laminate under compact tension (CT) with the use of finite element methods in Dassault Systèmes Abaqus® 2017 commercial software. Specifically, the scope of this study concerns the calculation of the translaminar fracture toughness of the NCF laminate implementing the physically-based failure criterion LaRC05 [1] as a build-in subroutine in Abaqus. The NCF blanket is consisted of three plies in which the material orientations, 450, 00, -450 are modelled explicitly, while at tow level, fibres, resin and stitches are homogenised with the rule of mixtures. The results of the simulation are compared to existing test results [2] and show good correlation at the pure elastic region, while towards crack onset and propagation mean deviation of approximately 12% is observed.
Mohsin MAA, Iannucci L, Greenhalgh E, 2020, Numerical and experimental analysis of high-velocity impact behaviour of carbon fibre reinforced thermoplastic composites
The low, medium and high-velocity impact resistance of fibre reinforced thermoplastic and thermosetting composites have continually attracted interest in automotive, aerospace and military applications. This research aims to characterise the high-velocity impact (HVI) response of a carbon fibre reinforced thermoplastic (CFRTP) composite system which is comprised of non-crimp fabric (NCF) biaxial 0/90 T700 carbon pre-impregnated with polyphenylene sulphide (PPS) thermoplastic (TP) veils. The raw materials were provided by THERMOCOMP [1] and the composite panels were manufactured using a 40-tonne hydraulic laboratory press via thermoforming process. The HVI tests were performed with velocities ranging from 130 to 250m/s. The projectile used is a 16mm diameter spherical stainless steel with a mass of 16.5 ± 0.5g. The entry and exit velocities were measured to determine the V50 and the energy absorbed in cases where perforation occurs. The experimental procedure was then numerically simulated using a finite element (FE) solver LS-DYNA®. The numerical model is then validated and compared against the experimental gatherings with respect to the exit velocities and damage mechanism.
Gouskos D, Iannucci L, 2020, Finite element analysis of non-crimp fabric laminates under compact tension
© CCM 2020 - 18th European Conference on Composite Materials. All rights reserved. The present work regards the computational analysis of a triaxial [450/00/-450] non-crimp fabric (NCF) laminate under compact tension (CT) with the use of finite element methods in Dassault Systèmes Abaqus® 2017 commercial software. Specifically, the scope of this study concerns the calculation of the translaminar fracture toughness of the NCF laminate implementing the physically-based failure criterion LaRC05 [1] as a build-in subroutine in Abaqus. The NCF blanket is consisted of three plies in which the material orientations, 450, 00, -450 are modelled explicitly, while at tow level, fibres, resin and stitches are homogenised with the rule of mixtures. The results of the simulation are compared to existing test results [2] and show good correlation at the pure elastic region, while towards crack onset and propagation mean deviation of approximately 12% is observed.
Del Rosso S, Iannucci L, Curtis P, 2019, Finite element simulation of the braiding process, Mechanics of Advanced Materials and Modern Processes, Vol: 5
Braiding is one of the most common technique employed for the manufacture of fabrics and ropes. It is also commonly used to produce near-net shaped preforms for advanced fibre reinforced composites. This paper presents an explicit finite element approach to create and simulate the braiding process for the virtual manufacture of 2D braids. The process starts from the definition of an analytical function which describes the movement of the carriers on a braiding track plate. Models of idealised Maypole-type braiding machines are built and used to shape virtual yarns into braids. This procedure can be used in a parameter control fashion, to optimise or to create virtual braided structures, which can serve as input for other structural analyses. It is emphasised that multiple cylinders are required for the modelling of a multifilament yarn to achieve better correlation with the experimental results. A parametric study is presented to investigate the effect of the number of virtual cylinders to represent a real yarn and the shape of the final braid. Excellent correlation was found between the virtual models and the experimental results when comparing the braid angle and yarn width.
Mohsin M, Iannucci L, Greenhalgh E, 2019, Fibre-volume-fraction measurement of carbon fibre reinforced thermoplastic composites using thermogravimetric analysis, Heliyon, Vol: 5, ISSN: 2405-8440
The fibre-volume-fraction (FVF) measurement of fibre-reinforced polymers (FRPs) is crucial in understanding and characterising their mechanical performance. To date, there has not been a standardised, labour-efficient method in determining the FVF of a non-crimp fabric (NCF) carbon reinforced thermoplastic composites (CFRTPs). An alternative method such as thermogravimetric analysis (TGA) has merely been commonly used for carbon-fibre reinforced thermosets (CFRTSs) and glass-fibre reinforced thermosets (GFRTSs). Therefore, this paper reports a range of macro TGA measurements of the constituent materials of two NCF CFRTPs; (i) T700 carbon/polyamide6.6 (PA6.6) and (ii) T700 carbon/polyphenylene sulphide (PPS). The TGA measurements were performed using two different purge gases (air and nitrogen) and the mass degradation with respect to time, temperature and atmospheres were recorded and discussed. Additionally, fractographic analysis on the fibres was carried out to scrutinise and further discuss the findings following the TGA. It was concluded that TGA provided a suitable and reliable alternative method to measure the FVF of CFRTPs.
Katafiasz TJ, Iannucci L, Greenhalgh E, 2019, Development of a novel compact tension specimen to mitigate premature compression and buckling failure modes within fibre hybrid epoxy composites, Composite Structures, Vol: 207, Pages: 93-107, ISSN: 1879-1085
A Notched Curved Compact Tension (NCCT) and Extended Notched Curved Compact Tension (ENCCT) specimen geometry are presented for the measurement of translaminar critical strain energy release rates in composite laminates with low compressive to tensile strengths. Premature compressive and buckling failure occurred when a conventional Compact Tension (CT) specimen geometry (similar to ASTM E399 [1]) was utilised for monolithic Non-Crimp Fabric (NCF) S2-Glass / MTM57 epoxy and an interlayer fibre hybrid T700 carbon spread tow / NCF S2-glass epoxy composite. The NCCT and ENCCT specimen design methodology and manufacturing routes are presented where premature compressive failure was mitigated through a curvature at the rear of the profile and the introduction of a through-thickness groove that had been pre-cured along the crack growth region. The latter ensured that buckling was eliminated, whilst stable crack growth was achieved. The development involved FE model material validation and optimisation for the novel specimen design. Experimental tests presented both interlayer and intralayer fibre hybrid composites with good repeatability and low scatter within the results.
Syed Abdullah SIB, Iannucci L, Greenhalgh E, 2018, On the translaminar fracture toughness of vectran/epoxy composite material, Composite Structures, Vol: 202, Pages: 566-577, ISSN: 1879-1085
The mode I fracture toughness associated with fibre tensile failure was investigated for a Vectran/MTM57 composite system. A modified compact tension specimen was designed and manufactured to mitigate compressive and buckling failure due to the low compressive properties which are an inherent characteristic of Vectran fibres. On average, the mode I translaminar fracture toughness for Vectran/MTM57 was found to be approximately 130–145 kJ/m2 for initiation and 250–260 kJ/m2 for propagation. In contrast with other composite systems such as carbon and glass fibre, the fracture toughness of Vectran/MTM57 was found to be relatively higher, with up to 48.26% and 95.27% for initiation and propagation, respectively for some carbon fibre composite system; 9.93% and 68.6% for initiation and propagation, respectively for S2-Glass/epoxy system.
Iannucci L, Del Rosso S, Curtis P, et al., 2018, Understanding the thickness effect on the tensile strength property of Dyneema®HB26 laminates, Materials, Vol: 11, Pages: 1-18, ISSN: 1996-1944
In this study, an experimental and numerical investigation is presented on the effect of thickness and test rate within the pseudo static regime on the tensile properties of Dyneema®HB26 laminates. A detailed experimental presentation on the tensile testing of different thickness is presented and highlights the commonly seen observation that the tensile strength of a laminate reduces as a function of the specimen thickness. To understand these experimental observations, a constitutive material model of the individual macro fibril is developed and applied to modelling the fibre and upscaling to the laminate. The modelling strategy is implemented into ls-dyna and used to perform a parameter study on the specimen geometries used in the experimental study. The model assumes that the fibril strength is a function of the amorphous volume within the fibre and hence fibril. It can be observed that the experimental behaviour can be simulated by modelling the interface between laminate plies and the fibril, and hence fibre failure. The weak interfaces from the fibril to the laminate scale make the testing of fibres and laminates very difficult. Hence, it is proposed that the intrinsic fibril strength should be used as a measure of strength, and the fundamental strength is determined through numerical studies.
Razavi S, Iannucci L, 2018, Simulation of the braiding process in LS-DYNA®, 15th International LS-DYNA® User Conference - Composites, Pages: 1-8
Iannucci L, 2018, Design of composite ballistic protection systems, Comprehensive Composite Materials II, Pages: 308-331, ISBN: 9780081005330
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Mohsin MAA, Iannucci L, Greenhalgh ES, 2017, Low-velocity impact performance of carbon fibre reinforced thermoplastic composites for automotive applications, 21st International Conference on Composite Materials
© 2017 International Committee on Composite Materials. All rights reserved. The damage response of rectangular plates of three different composite systems; two carbon/thermoplastic (T700/polyamide 6.6 and T700/polyphenylene sulphide) and one carbon/thermoset (T700/MTM57), at three distinct energy levels (40, 100 and 160) has been characterised. The varying energy levels were determined to correspond to the several degrees of penetrability; no penetration (at 40), partial-penetration (at 100) and full-penetration (at 160). Each plate was subjected to an out-of-plane, localised impact using an INSTRON® drop-weight tower with a hemispherical impactor measuring 16 in diameter. Following the test results and data reduction, the low-velocity impact (LVI) performance of the different composite systems was ranked from best to worst (based on the amount of impact energy absorption per areal weight) as follows; (i) T700/PPS, (ii) T700/MTM57 and (iii) T700/PA6.6. Post-mortem analysis techniques such as C-scan and X-ray were used to investigate the extent of damage of each sample; it was concluded that the T700/PA6.6 and T700/MTM57 experienced comparable levels of localised penetration whereas the best-performing T700/PPS exhibited no penetration (even at the highest energy level) but instead, demonstrated relatively significant degree of delamination in comparison to other two.
Cwik T, Iannucci L, Curtis P, et al., 2017, Design and ballistic performance of hybrid composite laminates, Applied Composite Materials, Vol: 24, Pages: 717-733, ISSN: 0929-189X
This paper presents an initial design assessment of a series of novel, cost-effective, and hybrid composite materials for applications involving high velocity impacts. The proposed hybrid panels were designed in order to investigate various physical phenomenon occurring during high velocity impact on compliant laminates from a previous study on Dyneema® and Spectra®. In the first, screening phase of the study twenty different hybrid composite laminates were impacted with 20 mm Fragment Simulating Projectiles at 1 km/s striking velocity. The best performing concepts were put forward to phase II with other hybrid concepts involving shear thickening fluids, commonly used in low velocity impacts. The results indicated that it is possible to design hybrid laminates of similar ballistic performance as the reference Dyneema® laminate, but with lower material costs. The optimal hybrid concept involves a fibre reinforced Polypropylene front and a Dyneema® backing.
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