Effect of Continuous Micro Reinforcement and Processing Parameters on the Low-Velocity Impact Behaviour of Polymer Composite Materials

2019 ◽  
Vol 56 (2) ◽  
pp. 382-387
Author(s):  
Raluca Maier ◽  
Andrei Mandoc ◽  
Alexandru Paraschiv ◽  
Marcel Istrate
Keyword(s):  
Processing Parameters ◽  
Woven Fabrics ◽  
Low Velocity Impact ◽  
Stacking Sequence ◽  
Low Velocity ◽  
Velocity Impact ◽  
Damage Initiation ◽  
Ductility Index ◽  
Impact Tests ◽  
The Impact

Low velocity impact tests were conducted on quasi-isotropic [�45/0/90o]xs laminates under drop weight impact from 0.7m, corresponding to a 30J energy. In this respect modified epoxy blends reinforced with carbon and Kevlar woven fabrics laminates were developed using autoclave technology. The four configurations developed for low velocity impact tests aimed at investigating several aspects like: the effect of fiber type, stacking sequence and mainly technological processing parameters, on the impact performances. The recorded Load-Time curves were plotted and visual inspection, high resolution laser scanner were used to observe the fracture characteristics of the impacted composite laminates. The results obtained showed that for tested configurations, both stacking sequence and processing parameters directly linked to fiber volume fraction, have a strong effect on the impact performances. The amount of absorbed energy, ductility index was calculated for each configuration under study. The results obtained showed that hybrid configuration exhibits lower stiffness and damage initiation energy amount when compared to carbon reinforced configurations. Nevertheless, their damage propagation energy amount and ductility index was the uppermost. This behaviour was already reported previously [1] and is partially attributed to the higher elastic energy absorption of carbon fibers that delays the propagation of delamination, and fiber breakage. Lower tenacity obtained on hybrid laminates was attributed to both lack of resin local rinse saturate and to the intrinsic anisotropy of para-aramid fibers.

scholarly journals Ultrasonic Analysis of Damage in CFRP Resulting from Static Indentation and Low Velocity Impact

1993 ◽  
Vol 2 (3) ◽  
pp. 096369359300200
Author(s):  
H. Kaczmarek
Keyword(s):  
Impact Testing ◽  
Low Velocity Impact ◽  
Ultrasonic Tomography ◽  
Transverse Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Testing Procedures ◽  
Damage Initiation ◽  
Static Indentation ◽  
The Impact

In order to reduce hidden damage caused in CFRP by low velocity transverse impact, testing procedures must be established by understanding the impact phenomena and the roles of various parameters on damage initiation and growth. Hence, composite plates were stressed and an original method, “ultrasonic tomography,” was applied to detect delaminations on the interfaces. The results show the similarity of the damage growth resulting from static indentation and low velocity impact.

Low Velocity Impact of Flat and Doubly Curved Polycarbonate Panels

2015 ◽  
Vol 82 (4) ◽  
Author(s):  
G. O. Antoine ◽  
R. C. Batra
Keyword(s):  
Low Velocity Impact ◽  
Initial Slope ◽  
Low Velocity ◽  
Velocity Impact ◽  
Impact Speed ◽  
Damage Initiation ◽  
Finite Element Software ◽  
Curved Panel ◽  
Panel Thickness ◽  
The Impact

Three-dimensional finite transient deformations of polycarbonate (PC) panels impacted at low velocity by a hemispherical-nosed rigid cylinder have been studied by using the commercial finite element software ls-dyna with a thermo–elasto–viscoplastic material model for the PC incorporated in it as a user defined subroutine. The implementation of the subroutine has been verified by comparing analytical and numerical solutions of simple initial-boundary-value problems. The mathematical model of the low velocity impact problem has been validated by comparing the computed and the experimental results for the maximum deflection and time histories of the centroidal deflection. It is found that the initial slope of the reaction force between the impactor and the panel versus the indentation for a curved panel can be nearly 20 times that for the flat panel of the same thickness as the curved panel. For the impact velocities considered, it is found that the maximum effective plastic strain in the PC shell near the center of impact and the dominant deformation mode there strongly depend on the panel curvature, the panel thickness, and the impact speed. Effects of the panel curvature, the panel thickness, and the impact speed on stresses and strains developed in a panel are delineated. This information should help designers of impact resistant transparent panels such as an airplane canopy, automobile windshield, and goggles. However, damage initiation and propagation, and the final indentation induced in the clamped panels have not been computed.

Impact Behaviour of Woven Natural Silk Composite Face-Sheet Sandwiched Foam under Low Velocity Impact

2013 ◽  
Vol 774-776 ◽  
pp. 1242-1249 ◽  
Author(s):  
Albert U. Ude ◽  
Ahmad K. Ariffin ◽  
Che H. Azhari
Keyword(s):  
Impact Load ◽  
Energy Levels ◽  
Low Velocity Impact ◽  
Face Sheet ◽  
Low Velocity ◽  
Velocity Impact ◽  
Natural Silk ◽  
Damage Initiation ◽  
The Impact ◽  
Composite Face

This paper describes the result of an experimental investigation on the impact damage on woven natural silk/epoxy composite face-sheet and PVC foam core sandwich panel. The test panels were prepared by hand-lay-up method. The low-velocity impact response of the composites sandwich panels is studied at three energy levels of 32, 48, and 64 joule respectively. The focus is to investigate damage initiation, damage propagation, and mechanisms of failure. It was observed that absorption energy capability decreased as impact energy increased. There was deflection on each impact load configuration at some point but their margin was insignificant. Physical examination of the specimen show that damage areas increased with increase in impact load. The novelty of this research is the use of woven natural silk fabric as a reinforcement fibre.

Dynamic Characterization of Multi-Functional Sandwich Composites

2000 ◽  
Author(s):  
Uday K. Vaidya ◽  
Scott P. Nelson ◽  
Biju Mathew ◽  
Renee M. Rodgers ◽  
Mahesh V. Hosur
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Low Velocity Impact ◽  
Impact Behavior ◽  
Low Velocity ◽  
Velocity Impact ◽  
Damage Initiation ◽  
The Impact

Abstract This paper deals with an innovative integrated hollow (space) E-glass/epoxy core sandwich composite construction that possesses several multi-functional benefits in addition to the providing light-weight and bending stiffness advantages. In comparison to traditional foam and honeycomb cores, the integrated space core provides a means to route wires/rods, embed electronic assemblies, and store fuel and fire-retardant foam, among other conceivable benefits. In the current work the low velocity impact (LVI) response of innovative integrated sandwich core composites was investigated. Three thickness of integrated and functionality-embedded E-glass/epoxy sandwich cores were considered in this study — including 6mm, 9mm and 17 mm. The low-velocity impact results indicated that the hollow and functionality embedded integrated core suffered a localized damage state limited to a system of core members in the vicinity of the impact. Stacking of the core was an effective way of improving functionality and limiting the LVI damage in the sandwich plate. The functionality-embedded cores provided enhanced LVI resistance due to energy additional energy absorption mechanisms. The high strain rate (HSR) impact behavior of these sandwich constructions is also studied using a Split Hopkinson Pressure Bar (SHPB) at strain rates ranging from 163 to 653 per second. The damage initiation, progression and failure mechanisms under low velocity and high strain rate impact are investigated through optical and scanning electron microscopy.

EFFECT OF IMPACTOR MASS ON CFRP IN ARCTIC CONDITION UNDER LOW-VELOCITY IMPACT

2021 ◽  
Author(s):  
ARNOB BANIK ◽  
CHAO ZHANG ◽  
K. T. TAN
Keyword(s):  
Low Temperature ◽  
Composite Structures ◽  
Room Temperature ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Damage Initiation ◽  
Thermal Chamber ◽  
Low Mass ◽  
The Impact

This study investigates the impact response and damage characterization of carbon fiber reinforced polymer (CFRP) under low-velocity impact by impactors of different masses and velocities at 62J. Low-velocity impacts are conducted at room temperature (23ºC) as well as low temperature (-70ºC) conditions in the thermal chamber of the drop tower testing machine, Instron CEAST 9350. The aim is to observe composite behavior in the cold Arctic environment due to equal energy impacts. Moreover, a 3mm thickness of ice is created on the CFRP samples at -12ºC after 24 hours of freezing and impacted at -70ºC. The goal is to elucidate the contribution of surface ice on the overall impact damage of composites. X-ray micro-computed tomography is utilized to reveal the inner damages of the composite structures. Intralaminar damage in the form of fiber breakage is found as the dominant failure mode on the CFRP samples from 62J impacts. But differences in the delamination and matrix crack formation are identified for different mass-velocity configurations and environmental conditions. Results show that low mass impactors produce a larger damage initiation force on the composites at all temperatures, whereas no specific trend is observed in the peak force values due to severe fiber failure. Although higher mass impactors show longer impact duration, lower mass impactors develop greater damage on the CFRP, as seen by a greater reduction in specimen stiffness. Furthermore, the presence of ice is observed to have a minimal effect on the damage behavior of composites. But ice layer assists to reduce the amplitude of initial load drop by the low mass impactor and as such, less permanent displacement is identified in the CFRP specimens than both room temperature and low-temperature conditions. This study explores the understanding of the dynamic behavior of composites under low-temperature icy conditions.

Investigation of the Effects of Core Thickness on Low Velocity Impact Behaviors of Aluminum Honeycomb Composites

2021 ◽  
Author(s):  
Kasım Karataş ◽  
Okan Özdemir
Keyword(s):  
Sheet Material ◽  
Energy Levels ◽  
Impact Testing ◽  
Low Velocity Impact ◽  
Core Material ◽  
Low Velocity ◽  
Velocity Impact ◽  
Impact Tests ◽  
Aluminum Honeycomb ◽  
The Impact

Honeycomb structures are used where the weight to strength ratio is important. They are also preferred to absorb the energy from the blows received. In this study, low velocity impact behavior of aluminum honeycomb composites with different core thicknesses were investigated. Aluminum honeycombs used in this study are AL3003 honeycombs of 10 mm and 15 mm thicknesses. Glass fiber reinforced epoxy sheets with a thickness of 2 mm were used as the surface sheet material. Composite plates were produced by vacuum infusion method. The upper and lower face plates were cut in dimensions of 100x100 mm. The cut plates were attached to the core material with adhesive and a sandwich structure was formed. After bonding, low velocity impact tests were performed on these test samples at 40J, 100J and 160J energy levels using the composite CEAST Fractovis Plus impact testing machine. According to the results obtained from the impact tests, at higher energy levels, 15 mm thick composites have 10-15% higher energy absorption capacity than 10 mm.

scholarly journals Palliatives for Low Velocity Impact Damage in Composite Laminates

2017 ◽  
Vol 2017 ◽  
pp. 1-16 ◽  
Author(s):  
Mubarak Ali ◽  
S. C. Joshi ◽  
Mohamed Thariq Hameed Sultan
Keyword(s):  
Composite Laminates ◽  
Impact Damage ◽  
Laminated Composites ◽  
Low Velocity Impact ◽  
Normal Operation ◽  
Fibre Reinforcement ◽  
Low Velocity ◽  
Velocity Impact ◽  
Damage Initiation ◽  
The Impact

Fibre reinforced polymer laminated composites are susceptible to impact damage during manufacture, normal operation, maintenance, and/or other stages of their life cycle. Initiation and growth of such damage lead to dramatic loss in the structural integrity and strength of laminates. This damage is generally difficult to detect and repair. This makes it important to find a preventive solution. There has been abundance of research dealing with the impact damage evolution of composite laminates and methods to mitigate and alleviate the damage initiation and growth. This article presents a comprehensive review of different strategies dealing with development of new composite materials investigated by several research groups that can be used to mitigate the low velocity impact damage in laminated composites. Hybrid composites, composites with tough thermoplastic resins, modified matrices, surface modification of fibres, translaminar reinforcements, and interlaminar modifications such as interleaving, short fibre reinforcement, and particle based interlayer are discussed in this article. A critical evaluation of various techniques capable of enhancing impact performance of laminated composites and future directions in this research field are presented in this article.

scholarly journals Analysis of Impact Behaviour of Sisal-Epoxy Composites under Low Velocity Regime

2021 ◽  
Vol 31 (1) ◽  
pp. 57-63
Author(s):  
Vishwas Mahesh ◽  
Ashutosh Nilabh ◽  
Sharnappa Joladarashi ◽  
Satyabodh M. Kulkarni
Keyword(s):  
Impact Velocity ◽  
Epoxy Composite ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Impact Behaviour ◽  
Damage Initiation ◽  
Structural Applications ◽  
Laminate Thickness ◽  
The Impact

The present study concentrates on development of conceptual proof for sisal reinforced polymer matrix composite for structural applications subjected to low velocity impact using a finite element (FE) approach. The proposed sisal-epoxy composite of various thicknesses of 3.2 mm, 4 mm and 4.8 mm is subjected to different impact velocities of 1 m/s, 2 m/s and 3 m/s ranging in the low velocity impact regime to study the energy absorbed and damage mitigation behaviour of the proposed composite. The consequence of velocity of impact and thickness of laminate on the sisal epoxy composite’s impact behaviour is assessed statistically using Taguchi’s experimental design. Outcome of the present study discloses that the energy absorption increases with increased impact velocity and laminate thickness. However, the statistical study shows that impact velocity is predominant factor affecting the impact response of sisal epoxy composite laminate compared to laminate thickness. The role of matrix and fiber in damage initiation is studied using Hashin criteria and it is found that matrix failure is predominant over the fiber failure.

Improvement of Biocomposite Performance under Low-Velocity Impact Test - A Review

2021 ◽  
Vol 893 ◽  
pp. 67-74
Author(s):  
Usha Kiran Sanivada ◽  
Gonzalo Mármol ◽  
Francisco P. Brito ◽  
Raul Fangueiro
Keyword(s):  
Composite Structures ◽  
Impact Test ◽  
Impact Resistance ◽  
Vital Role ◽  
Low Velocity Impact ◽  
Efficient Design ◽  
Low Velocity ◽  
Velocity Impact ◽  
Impact Tests ◽  
The Impact

The study of the impact energy and the composite behaviour plays a vital role in the efficient design of composite structures. Among the various categories of impact tests, it is essential to study low-velocity impact tests as the damage generated due to these loads is often not visible to the naked eye. The internal damages can reduce the strength of the composites and hence the impact behaviour must be addressed specifically for improving their applications in the transport industry. The main aim of this paper is to provide a comprehensive review of the work focusing on the assessment of biocomposites performance under low impact velocity, the different deformations, and damage mechanisms, as well the methods to improve the impact resistance.

Modeling and simulation of impact behavior of 3D woven solid structure for ballistic application

2020 ◽  
pp. 152808372098046
Author(s):  
Lekhani Tripathi ◽  
Soumya Chowdhury ◽  
BK Behera
Keyword(s):  
Numerical Models ◽  
Woven Fabrics ◽  
Ballistic Impact ◽  
Woven Fabric ◽  
Low Velocity Impact ◽  
Impact Behavior ◽  
Low Velocity ◽  
Velocity Impact ◽  
The Impact ◽  
Analytical Approaches

This study was carried out to understand and evaluate the response of 3 D woven fabrics upon the simulated ballistic forces. Under the low-velocity impact, analytical and numerical models were developed for determining the impact energy, which was used to evaluate the ballistic impact of projectile onto multiple-layered woven fabric panels based on the ballistic impact of single textile yarns. The behavior of primary and secondary yarns in a fabric under the ballistic impact was analyzed by both the models. The mechanisms of failure and energy dissipation of Kevlar fabric subjected to low-velocity impact were numerically investigated by using the ABAQUS platform as a tool of finite element method (FEM). The results obtained from numerical and analytical approaches were validated against experimental value which showed a good agreement.

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