Influence of patch lay-up configuration and hybridization on low velocity impact and post-impact tensile response of repaired glass fiber reinforced plastic composites

2018 ◽  
Vol 53 (1) ◽  
pp. 3-17 ◽  
Author(s):  
J Jefferson Andrew ◽  
Sivakumar M Srinivasan ◽  
A Arockiarajan
Keyword(s):  
Glass Fiber ◽  
Impact Energy ◽  
Volume Fraction ◽  
Glass Fibers ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Static Tensile ◽  
The Impact

This paper aims to investigate the effect of homogenous and hybrid external patches based on plain weave woven glass and Kevlar fabric on low velocity impact and quasi-static tensile after impact response of adhesively bonded external patch repairs in damaged glass/epoxy composite laminates. In all hybrid patches, the proportion of Kevlar and glass fibers were equal (i.e. 50% of Kevlar and 50% of glass by volume fraction), while lay-up configuration was different. This further enables to study the associated effect of hybridization and lay-up configuration on impact response of the repaired laminates. The intent of using hybrid external patches is to combine the excellent high displacement-to-failure property of Kevlar fiber as a ductile reinforcement with the superior mechanical property of glass fiber as a brittle reinforcement. The effect of glass/Kevlar content on impact response and tensile after impact response was investigated for various incident impact energy levels, such as 2, 4, 6, and 8 J. Results showed that hybridization and lay-up configurations of the external patches played a significant role on low velocity impact and quasi-static tensile after impact response of the repaired glass/epoxy specimens. Specimens repaired using intra-ply hybrid patches showed better impact properties and damage tolerance capability than that of the virgin and other repaired specimens. In specific, the use of intra-ply hybrid patches reduced the impact energy absorption by 10.17% in comparison to the virgin specimens at impact energy of 8 J.

Response and failure modes of biaxial warp-knitted flexible composite subject to low-velocity impact

2021 ◽  
pp. 152808372110154
Author(s):  
Ziyu Zhao ◽  
Tianming Liu ◽  
Pibo Ma
Keyword(s):  
Impact Energy ◽  
Linear Density ◽  
Failure Modes ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Minor Effect ◽  
Low Velocity ◽  
Velocity Impact ◽  
Flexible Composites ◽  
The Impact

In this paper, biaxial warp-knitted fabrics were produced with different high tenacity polyester linear density and inserted yarns density. The low-velocity impact property of flexible composites made of polyurethane as matrix and biaxial warp-knitted fabric as reinforcement has been investigated. The effect of impactor shape and initial impact energy on the impact response of flexible composite is tested. The results show that the initial impact energy have minor effect on the impact response of the biaxial warp-knitted flexible composites. The impact resistance of flexible composite specimen increases with the increase of high tenacity polyester linear density and inserted yarns density. The damage morphology of flexible composite materials is completely different under different impactor shapes. The findings have theoretical and practical significance for the applications of biaxial warp-knitted flexible composite.

Effect of Foam Core Density and Facesheet Thickness on the Low Velocity Impact Response of Foam Core Sandwich Composites

2000 ◽  
Author(s):  
M. Motuku ◽  
R. M. Rodgers ◽  
S. Jeelani ◽  
U. K. Vaidya
Keyword(s):  
Impact Energy ◽  
Maximum Load ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Foam Core ◽  
Low Velocity ◽  
Core Density ◽  
Failure Characteristics ◽  
Velocity Impact ◽  
The Impact

Abstract The effect of foam core density and facesheet thickness on the low velocity impact response and damage evolution in homogeneous foam core sandwich composites was studied. The failure characteristics, initiation and evolution of damage as well as the effect of impact energy were investigated. A Dynatup 8210 Impact Test Machine was utilized to conduct the low-velocity impact tests. Characterization of the impact response was performed by comparing the impact load histories, impact plots and failure characteristics. Fractography analysis was conducted through the use of scanning electron microscopy (SEM) and optical microscopy. Three types of foam cores with different densities, namely Airlite B12.5, Rohacell IG-71R63 and Airex R63.5 foam cores, were used to study the effect of core density. Considering four groups of facesheets made of different layers of cross-ply carbon prepregs performed the effect of facesheet thickness. For all the facesheet thicknesses (0.011-0.894-cm thick) and impact energy (11-40 J) range considered in this study, the maximum load (Pm), deflection-at-maximum load (δm) and time-to-maximum load (tm) exhibited strong influence or dependence on the type of foam core as opposed to the facesheet thickness. The energy-to-maximum load (Em), total energy absorbed (Et) and total energy-to-impact energy (Et/Eimp) ratio became less sensitive on the foam core density (or type) with increasing facesheet thickness. A transition point from foam core to facesheet controlled impact behavior as a function of impact energy level was observed. The impact parameters varied either linearly or parabolically with impact energy depending on the impact energy level, type of foam core and facesheet thickness. Excellent repeatability of impact data was generally obtained with increase in foam core density.

Effect of Graphene Platelets/Fiber on Plastics Nanocomposites under Low-Velocity Impact Response

2016 ◽  
Vol 852 ◽  
pp. 23-28
Author(s):  
S. Subha ◽  
Battu Sai Krishna ◽  
Dalbir Singh ◽  
R. Gokulnath
Keyword(s):  
Energy Absorption ◽  
Impact Energy ◽  
Laminate Plate ◽  
Absorption Capacity ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Energy Absorption Capacity ◽  
Velocity Impact ◽  
The Impact

In this study, an attempt has made to explore the low-velocity impact response of a Carbon/epoxy laminate (CFRP) and E-Glass/epoxy laminates (GFRP). The composite was reinforced with Graphene Nanoplatelets (GnPs) and impact energy absorption capacity was studied. The plain GFRP and plain CFRP were served as a baseline for comparison. These composite laminate plates were fabricated using hand layup technique. The tests were carried out on the laminate plate as per ASTM D5628 FD. Impact tests were performed using a specially designed vertical drop-weight testing machine with an impactor mass of 1.926 kg. The result shows that laminate plate reinforced with GnPs reinforcement enhances the impact energy absorption capacity of the composites almost 4.5 % in the case Carbon/epoxy laminate and 3.5 % in the case of and E-glass/epoxy laminate. The enhanced impact resistance could be attributed to increased interlaminar fracture toughness of the fibres.

Experimental investigation on the effects of glass fiber hybridization on the low-velocity impact response of filament-wound carbon-based composite pipes

2020 ◽  
pp. 096739112093818
Author(s):  
Naseer H Farhood ◽  
Saravanan Karuppanan ◽  
Hamdan H Ya ◽  
MTH Sultan
Keyword(s):  
Carbon Fiber ◽  
Glass Fiber ◽  
Impact Energy ◽  
Impact Damage ◽  
Glass Fibers ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Damage Resistance ◽  
Velocity Impact ◽  
Composite Pipes

Recently, the incorporation of several different types of fibers into a single matrix has led to the development of superior hybrid composite properties at a cheaper cost. Fiber hybridization is one of the active strategies to toughen composites and improve impact damage resistance. However, the extraordinary high strength and stiffness of the carbon fiber as well as its lower damage tolerance make it more susceptible under the impact loading. This article mainly aims to improve impact damage resistance of carbon fiber pipes through fiber hybridization strategy with glass fibers under low-velocity impact. The composite pipes reinforced with thin internal liner of high-density polyethylene were fabricated through filament winding technology. Eight pipe configurations with different stacking sequences and fiber content ratios with a constant winding angle of [Formula: see text] were fabricated and tested under impact energies, 50 and 100 J. The damage characterization was evaluated using the optical imaging and mechanical micrograph sectioning technique. Results indicate that the hybrid configurations showed better energy absorption than reference carbon fibers specimen under 50 J impact energy. Specifically, specimens with glass fibers on the exterior side and alternative configuration of carbon–glass fibers showed better impact resistance with less damage observed. Meanwhile, the specimens with glass fiber on the exterior side suffered from extreme damage with increase in the energy absorption and maximum displacement for both fiber content ratios under 100 J of impact energy.

Low-velocity impact response of pre-stressed glass fiber/nanotube filled epoxy composite tubes

2020 ◽  
pp. 002199832096155
Author(s):  
Mustafa Taşyürek ◽  
Memduh Kara
Keyword(s):  
Glass Fiber ◽  
Ultrasonic Method ◽  
Energy Levels ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Impact Behavior ◽  
Low Velocity ◽  
Velocity Impact ◽  
Force Time ◽  
The Impact

The aim of this study is to investigate the low velocity impact behavior of pre-stressed glass fiber/epoxy (GRP) nanocomposite tubes. During the production of filament wound tubes with a winding angle of ±55°, carbon nanotubes (CNT) were introduced to the epoxy resin at 0.5%wt and 1.0%wt by ultrasonic method. The nanocomposite tubes were pre-stressed to 32 bars internal pressure, one of the specified operating pressures according to ANSI/AWWA C950 standards. Low velocity impact tests were performed on the pure and CNT added pre-stressed GRP tubes at 5, 10 and 15 Joule energy levels. As a result of the experiments, the contact force-time, force-displacement graphs and absorbed energy values by the samples were obtained. In addition, the damage zones on the specimens were investigated. The effects of CNT reinforcements on the impact response and damage mechanisms of the specimens were evaluated. By adding CNT, it was observed that the damage areas of the samples decreased and was found to affect the impact response of nanocomposite tubes.

A Study of Impact Response of Composite Pipe

1991 ◽  
Vol 113 (3) ◽  
pp. 182-188 ◽  
Author(s):  
S. S. Pang ◽  
A. A. Kailasam
Keyword(s):  
Glass Fiber ◽  
Method Development ◽  
Damage Zone ◽  
Test Method ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Composite Pipe ◽  
The Impact

The objective of this study was to gain a better understanding of the low-velocity impact phenomena of composite pipe. The focus was on test method development, and material and damage characterization. A drop weight tower tester was designed in this investigation. The dynamic tests were conducted using three different impactor geometries, velocities, and masses. It was found that the damage was localized and on the outer surface of the pipe in the case of the conical and wedge tip impactors. On the other hand, the damage zone was larger than the impact zone for the hemispherical impactor, and cracks were first seen within the inner surface of the pipe. This implies that the hemispherical tip impactor caused more damage to the pipe than the conical or wedge tips. The energy absorbed slightly increased with an increase in velocity or in mass. The contact period for the conical impactor was the longest. The velocity and mass of the impactor had only a slight effect on that period. The wedge impactor generated the largest peak force. The energy absorbed by the two composite pipes under low-velocity impact was studied. The specimen-1, Derakane 411-45 resin with less glass fiber, seemed to absorb more energy compared to the specimen-2, Derakane 470-36 resin with more glass fiber. In addition, the specimen-2 exhibited a slightly higher maximum impact force. Therefore, impact response is sensitive to fiber content.

scholarly journals Experimental Investigation of Impactor Diameter Effect on Low-Velocity Impact Response of CFRP Laminates in a Drop-Weight Impact Event

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4131 ◽  
Author(s):  
Hongyi Cao ◽  
Mengyuan Ma ◽  
Mingshun Jiang ◽  
Lin Sun ◽  
Lei Zhang ◽  
...  
Keyword(s):  
Impact Energy ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Internal Damage ◽  
Velocity Impact ◽  
Damage Characteristics ◽  
The Impact ◽  
Dent Depth ◽  
Delamination Area

The present study delved into the effect of impactor diameter on low velocity impact response and damage characteristics of CFRP. Moreover, the phased array ultrasonic technique (PAUT) was adopted to identify the impact damages based on double-sided scanning. Low-velocity impact tests were carried out using three hemispherical impactors with different diameters. The relationship of impact response and impactor diameters was analyzed by ultrasonic C-scans and S-scans, combined with impact response parameters. Subsequently, the damage characteristics were assessed in terms of dent depth, delamination area and extension shape via the thickness, and the relationships between absorbed energy, impactor displacement, dent depth and delamination area were elucidated. As revealed from experiment results, double-sided PAUT is capable of representing the internal damage characteristics more accurately. Moreover, the impactor diameter slightly affects the impact response under small impact energy, whereas it significantly affects the impact response under large impact energy.

Repeated low-velocity impact response and damage mechanism of glass fiber aluminium laminates

2019 ◽  
Vol 84 ◽  
pp. 995-1010 ◽  
Author(s):  
Lijun Li ◽  
Lingyu Sun ◽  
Taikun Wang ◽  
Ning Kang ◽  
Wan Cao
Keyword(s):  
Glass Fiber ◽  
Damage Mechanism ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact

Effect of SiO2 Nanoparticles on the Mechanical and Low Velocity Impact Properties of Epoxy/Glass Composites

2016 ◽  
Vol 838 ◽  
pp. 29-35
Author(s):  
Michał Landowski ◽  
Krystyna Imielińska
Keyword(s):  
Flexural Strength ◽  
Energy Absorption ◽  
Impact Energy ◽  
Epoxy Matrix ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Nanoparticle Suspension ◽  
Impact Properties ◽  
Velocity Impact ◽  
The Impact

Flexural strength and low velocity impact properties were investigated in terms of possibile improvements due to epoxy matrix modification by SiO2 nanoparticles (1%, 2%, 3%, 5%, 7%wt.) in glass/epoxy laminates formed using hand lay-up method. The matrix resin was Hexion L285 (DGEBA) with Nanopox A410 - SiO2 (20 nm) nanoparticle suspension in the base epoxy resin (DGEBA) supplied by Evonic. Modification of epoxy matrix by variable concentrations of nanoSiO2 does not offer significant improvements in the flexural strength σg, Young’s modulus E and interlaminar shear strength for 1% 3% and 5% nanoSiO2 and for 7% a slight drop (up to ca. 15-20%) was found. Low energy (1J) impact resistance of nanocomposites represented by peak load in dynamic impact characteristics was not changed for nanocompoosites compared to the unmodified material. However at higher impact energy (3J) nanoparticles appear to slightly improve the impact energy absorption for 3% and 5%. The absence or minor improvements in the mechanical behaviour of nanocomposites is due to the failure mechanisms associated with hand layup fabrication technique: (i.e. rapid crack propagation across the extensive resin pockets and numerous pores and voids) which dominate the nanoparticle-dependent crack energy absorption mechanisms (microvoids formation and deformation).

Low-velocity impact response of wood-strand sandwich panels and their components

Holzforschung ◽  
2018 ◽  
Vol 72 (8) ◽  
pp. 681-689 ◽  
Author(s):  
Mostafa Mohammadabadi ◽  
Vikram Yadama ◽  
LiHong Yao ◽  
Debes Bhattacharyya
Keyword(s):  
Energy Absorption ◽  
Impact Energy ◽  
Failure Modes ◽  
Sandwich Panels ◽  
Low Velocity Impact ◽  
Insulation Material ◽  
Low Velocity ◽  
Velocity Impact ◽  
Section Modulus ◽  
The Impact

AbstractProfiled hollow core sandwich panels (SPs) and their components (outer layers and core) were manufactured with ponderosa and lodgepole pine wood strands to determine the effects of low-velocity impact forces and to observe their energy absorption (EA) capacities and failure modes. An instrumented drop weight impact system was applied and the tests were performed by releasing the impact head from 500 mm for all the specimens while the impactors (IMPs) were equipped with hemispherical and flat head cylindrical heads. SPs with cavities filled with a rigid foam insulation material (SPfoam) were also tested to understand the change in EA behavior and failure mode. Failure modes induced by both IMPs to SPs were found to be splitting, perforating, penetrating, core crushing and debonding between the core and the outer layers. SPfoams absorbed 26% more energy than unfilled SPs. SPfoams with urethane foam suffer less severe failure modes than SPs. SPs in a ridge-loading configuration absorbed more impact energy than those in a valley-loading configuration, especially when impacted by a hemispherical IMP. Based on the results, it is evident that sandwich structure is more efficient than a solid panel concerning impact energy absorption, primarily due to a larger elastic section modulus of the core’s corrugated geometry.

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