scholarly journals Flexural Toughness as an Attribute for Impact Damage Evaluation of Composite Laminates

2011 ◽  
Author(s):  
Mohammad Alemi-Ardakani ◽  
Abbas S. Milani ◽  
Spiro Yannacopoulos ◽  
David Trudel-Boucher ◽  
Golnaz Shokouhi
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Composite Laminates ◽  
Visual Inspection ◽  
Impact Damage ◽  
Impact Resistance ◽  
Damage Evaluation ◽  
Flexural Toughness ◽  
Post Impact ◽  
The Impact

Popularity and application of composite materials are increasing in several industries including transportation, construction and aerospace. The mechanical properties of these materials should be known to engineers to be able to design/select new products. Impact resistance is one of the properties which have been studied extensively over the past years and still is an ongoing topic in composites research. Since analytical solutions have not been fully developed for the impact characterization of anisotropic materials, researchers often perform mechanical testing in conjunction with visual inspection methods to investigate the impact behavior of composite materials. The present study shows that flexural toughness can be used as a parameter in the design/material selection stage in the evaluation of pre- and post-impact damage of composite laminates. A series of drop-weight impact tests, using a 200J energy level, were performed on specimens made of four different stacking configurations of TWINTEX® and unidirectional laminates (polypropylene and glass fiber commingled composites) according to ASTM D7136. The damaged areas of the impacted specimens were measured using image analysis. Four-point flexural testing was then carried out, based on ASTM D7264, on both non-impacted and impacted specimens. Damaged area and flexural toughness, along with a set of other commonly used mechanical properties, were selected as measures for damage evaluation. Comparison of results before and after impact and under different criteria showed that in the present case study, visual inspection is not sufficient in predicting the post-impact properties of the tested specimens and can be misleading. On the other hand, flexural toughness could give a much clearer perspective on the extent of post-impact resistance of the specimens.

IMPACT RESISTANCE PROPERTIES OF KEVLAR/GLASS FIBER HYBRID COMPOSITE LAMINATES

2015 ◽  
Vol 76 (3) ◽  
Author(s):  
Norazean Shaari ◽  
Aidah Jumahat ◽  
M. Khafiz M. Razif
Keyword(s):  
Glass Fiber ◽  
Hybrid Composite ◽  
Composite Laminates ◽  
Impact Damage ◽  
Impact Resistance ◽  
Impact Behavior ◽  
Slight Reduction ◽  
Depth Of Penetration ◽  
Damage Degree ◽  
The Impact

In this paper, the impact behavior of Kevlar/glass fiber hybrid composite laminates was investigated by performing the drop weight impact test (ASTM D7136). Composite laminates were fabricated using vacuum bagging process with an epoxy matrix reinforced with twill Kevlar woven fiber and plain glass woven fiber. Four different types of composite laminates with different ratios of Kevlar to glass fiber (0:100, 20:80, 50:50 and 100:0) were manufactured. The effect of Kevlar/glass fiber content on the impact damage behavior was studied at 43J nominal impact energy. Results indicated that hybridization of Kevlar fiber to glass fiber improved the load carrying capability, energy absorbed and damage degree of composite laminates with a slight reduction in deflection. These results were further supported through the damage pattern analysis, depth of penetration and X-ray evaluation tests. Based on literature work, studies that have been done to investigate the impact behaviour of woven Kevlar/glass fiber hybrid composite laminates are very limited. Therefore, this research concentrates on the effect of Kevlar on the impact resistance properties of woven glass fibre reinforced polymer composites.

scholarly journals Bird-Strike Resistance of Composite Laminates with Different Materials

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 129 ◽  
Author(s):  
Yadong Zhou ◽  
Youchao Sun ◽  
Tianlin Huang
Keyword(s):  
Composite Materials ◽  
Composite Laminates ◽  
Impact Damage ◽  
Dynamic Properties ◽  
Dynamic Structure ◽  
Strength Properties ◽  
Bird Strike ◽  
Particle Hydrodynamics ◽  
Bird Impact ◽  
The Impact

To obtain some basic laws for bird-strike resistance of composite materials in aeronautical application, the high-velocity impact behaviors of composite laminates with different materials were studied by numerical methods. The smoothed particle hydrodynamics (SPH) and finite element method (FEM) coupling models were validated from various perspectives, and the numerical results were comparatively investigated. Results show that the different composite materials have relatively little effect on projectile deformations during the bird impact. However, the impact-damage distributions can be significantly different for different composite materials. The strength parameters and fracture energy parameters play different roles in different damage modes. Lastly, modal frequency was tentatively used to explain the damage behavior of the composite laminates, for it can manifest the mass and stiffness characteristics of a dynamic structure. The dynamic properties and strength properties jointly determine the impact-damage resistance of composite laminates under bird strike. Future optimization study can be considered from these two aspects.

Impact Resistance of SM Joints Formed With ICA

2002 ◽  
Vol 124 (4) ◽  
pp. 374-378 ◽  
Author(s):  
C. M. Lawrence Wu ◽  
Robert K. Y. Li ◽  
N. H. Yeung
Keyword(s):  
Impact Damage ◽  
Impact Resistance ◽  
High Energy ◽  
Bending Test ◽  
Conductive Adhesives ◽  
Energy Impact ◽  
Split Hopkinson ◽  
Post Impact ◽  
Impact Bending ◽  
The Impact

Isotropic conductive adhesives (ICA) have been considered as replacement materials for lead-tin solder alloys. In this paper, the post-impact shear strength of ICA surface mount (SM) joints was obtained experimentally and compared with that of SM lead-tin joints. The dynamic impact energy was provided in the form of three-point bending on the PCB using equipment called the split Hopkinson bar. Strain rates of over 4000/s were used for the impact bending test. The action of impact bending was used to simulate the effect on the PCB and the interconnection as a result of high energy impact on an electronic equipment. Shear test was then performed to examine the change in strength of the ICA joints as a result of impact damage. It was found that the SM ICA joints failed due to impact at a strain rate just over 4000/s. Microstructural examination carried out using a scanning electron microscope revealed that the interface between the ICA and copper pad on the PCB was the weakest region of the joint.

scholarly journals Impact Response and Damage Tolerance of Hybrid Glass/Kevlar-Fibre Epoxy Structural Composites

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2591
Author(s):  
Vasudevan Alagumalai ◽  
Vigneshwaran Shanmugam ◽  
Navin Kumar Balasubramanian ◽  
Yoganandam Krishnamoorthy ◽  
Velmurugan Ganesan ◽  
...  
Keyword(s):  
Composite Laminates ◽  
High Speed ◽  
Fibre Orientation ◽  
Impact Damage ◽  
Charpy Impact ◽  
Compression Moulding ◽  
Post Impact ◽  
Ballistic Test ◽  
Interlaminar Shear ◽  
The Impact

The present study is aimed at investigating the effect of hybridisation on Kevlar/E-Glass based epoxy composite laminate structures. Composites with 4 mm thickness and 16 layers of fibre (14 layers of E-glass centred and 2 outer layers of Kevlar) were fabricated using compression moulding technique. The fibre orientation of the Kevlar layers had 3 variations (0, 45 and 60°), whereas the E-glass fibre layers were maintained at 0° orientation. Tensile, flexural, impact (Charpy and Izod), interlaminar shear strength and ballistic impact tests were conducted. The ballistic test was performed using a gas gun with spherical hard body projectiles at the projectile velocity of 170 m/s. The pre- and post-impact velocities of the projectiles were measured using a high-speed camera. The energy absorbed by the composite laminates was further reported during the ballistic test, and a computerised tomographic scan was used to analyse the impact damage. The composites with 45° fibre orientation of Kevlar fibres showed better tensile strength, flexural strength, Charpy impact strength, and energy absorption. The energy absorbed by the composites with 45° fibre orientation was 58.68 J, which was 14% and 22% higher than the 0° and 60° oriented composites.

Low Velocity Impact Resistance of Hybrid Woven Glass Fiber-Carbon Fiber/Vinyl Ester Composite Laminates

2012 ◽  
Vol 488-489 ◽  
pp. 501-505
Author(s):  
Zafarullah Khan
Keyword(s):  
Mechanical Properties ◽  
Glass Fiber ◽  
Composite Laminates ◽  
Hybrid Composites ◽  
Impact Resistance ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Glass Fiber Composites ◽  
Woven Glass Fiber ◽  
The Impact

In recent years, for the purpose of achieving enhanced mechanical properties of fiber reinforced composites, hybridized composites containing a combination of two or more types of fiber reinforcements have been explored. Perhaps the main parameter which controls the mechanical properties of the hybrid composites is the flexibility to arrange the hybrid fiber reinforcement layers in a variety of ways within the hybrid laminate. In this study, low velocity drop weight impact resistance of plain weave woven glass and carbon hybrid composites has been investigated. The study explores the effects of intra-ply arrangement sequence on the impact resistance of 24 and 32 ply laminates in which glass and the carbon plies have been differently stacked. The results show that impact resistance of woven glass fiber composites can be enhanced by hybridizing woven glass fabrics with woven carbon fabrics. The results indicate that the impact resistance is a function of the positions of the glass and carbon layers in the hybridized inter ply laminates.

Impact Resistance of SM Joints Formed With ICA

2003 ◽  
Vol 125 (1) ◽  
pp. 93-97 ◽  
Author(s):  
C. M. Lawrence Wu ◽  
Robert K. Y. Li ◽  
N. H. Yeung
Keyword(s):  
Impact Damage ◽  
Impact Resistance ◽  
High Energy ◽  
Bending Test ◽  
Conductive Adhesives ◽  
Energy Impact ◽  
Split Hopkinson ◽  
Post Impact ◽  
Impact Bending ◽  
The Impact

Isotropic conductive adhesives (ICA) have been considered as replacement materials for lead-tin solder alloys. In this paper, the post-impact shear strength of ICA surface mount (SM) joints was obtained experimentally and compared with that of SM lead-tin joints. The dynamic impact energy was provided in the form of three-point bending on the PCB using equipment called the split Hopkinson bar. Strain rates of over 4000/s were used for the impact bending test. The action of impact bending was used to simulate the effect on the PCB and the interconnection as a result of high energy impact on an electronic equipment. Shear test was then performed to examine the change in strength of the ICA joints as a result of impact damage. It was found that the SM ICA joints failed due to impact at a strain rate just over 4000/s. Microstructural examination carried out using a scanning electron microscope revealed that the interface between the ICA and copper pad on the PCB was the weakest region of the joint.

TEMPERATURE EFFECT OF LOW VELOCITY IMPACT RESISTANCE OF GLASS/EPOXY LAMINATES

2010 ◽  
Vol 24 (15n16) ◽  
pp. 2657-2663 ◽  
Author(s):  
KI-WEON KANG ◽  
HEUNG-SEOB KIM ◽  
TAE-JIN CHUNG ◽  
SEUNG-KEE KOH
Keyword(s):  
Composite Laminates ◽  
Impact Damage ◽  
Testing Machine ◽  
Impact Resistance ◽  
Impact Testing ◽  
Low Velocity Impact ◽  
Effect Of Temperature ◽  
Low Velocity ◽  
Damage Resistance ◽  
The Impact

This paper aims to evaluate the effect of temperature on impact damage resistance of glass/epoxy laminates. A series of impact tests were performed using an instrumented impact-testing machine at temperature ranging from -40°C to +80°C. The resulting impact damage was measured using back light method. The impact resistance parameters were employed to understand the damage resistance. It was observed that temperature has a little effect on the impact responses of composite laminates. The damage resistance of glass/epoxy laminates is somewhat deteriorated at two opposite extremes of the studied temperature range and this behavior is likely due to the property change of glass/epoxy laminates under extreme temperatures

The effect of different structural designs on impact resistance to carbon fiber foam sandwich structures

e-Polymers ◽  
2021 ◽  
Vol 22 (1) ◽  
pp. 12-18
Author(s):  
Kang Yang ◽  
Peng Gong ◽  
Li Yang ◽  
Liguo Zhang ◽  
Ziao Zhang ◽  
...  
Keyword(s):  
Composite Materials ◽  
Carbon Fiber ◽  
Impact Energy ◽  
Sandwich Structure ◽  
Impact Damage ◽  
Impact Resistance ◽  
Foam Core ◽  
Damage Area ◽  
Damage Depth ◽  
The Impact

Abstract The development of the composite materials in the past decades has made the composite materials more and more widely used in various engineering fields. The mechanical properties of the composite materials are gradually improved, especially the impact resistance. In this article, the damage of carbon fiber foam sandwich structure (material grade: W-3021FF/H60) under different sandwich thicknesses and impact energies was studied. Ultrasonic C-scan was used to measure the depth and area of impact damage area. Finally, the impact energy and foam core thickness on impact damage was analyzed by test results. The results show that the impact damage depth and area of foam sandwich structure were positively related to the impact energy, and with the increase in the impact energy, the growth rate of damage depth and damage area changes; the greater the thickness of the foam core was, the stronger the span-direction guiding energy for impact energy, the larger the damage area and the smaller the damage depth. Under the same energy, the more the layers of carbon fiber cloth with the foam sandwich structure, the larger the impact damage depth and the smaller the impact damage area. The proportion of ±45° ply in the foam sandwich structure can improve its impact resistance.

Effect of combined drink cans and steel fibers on the impact resistance and mechanical properties of concrete

2020 ◽  
Vol 14 (2) ◽  
pp. 6734-6742
Author(s):  
A. Syamsir ◽  
S. M. Mubin ◽  
N. M. Nor ◽  
V. Anggraini ◽  
S. Nagappan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Impact Resistance ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Indirect Tensile ◽  
The Impact

This study investigated the combine effect of 0.2 % drink cans and steel fibers with volume fractions of 0%, 0.5%, 1%, 1.5%, 2%, 2.5% and 3% to the mechanical properties and impact resistance of concrete. Hooked-end steel fiber with 30 mm and 0.75 mm length and diameter, respectively was selected for this study.  The drinks cans fiber were twisted manually in order to increase friction between fiber and concrete. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the strength performance of concrete, especially the compressive strength, flexural strength and indirect tensile strength. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the compressive strength, flexural strength and indirect tensile strength by 2.3, 7, and 2 times as compare to batch 1, respectively. Moreover, the impact resistance of fiber reinforced concrete has increase by 7 times as compared to non-fiber concretes. Moreover, the impact resistance of fiber reinforced concrete consistently gave better results as compared to non-fiber concretes. The fiber reinforced concrete turned more ductile as the dosage of fibers was increased and ductility started to decrease slightly after optimum fiber dosage was reached. It was found that concrete with combination of 2% steel and 0.2% drink cans fibers showed the highest compressive, split tensile, flexural as well as impact strength.    

scholarly journals Effect of SWCNT-Tuball Paper on the Lightning Strike Protection of CFRPs and Their Selected Mechanical Properties

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3140
Author(s):  
Kamil Dydek ◽  
Anna Boczkowska ◽  
Rafał Kozera ◽  
Paweł Durałek ◽  
Łukasz Sarniak ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Copper Foil ◽  
Impact Resistance ◽  
Mechanical Analysis ◽  
Lightning Strike ◽  
Single Wall Carbon Nanotubes ◽  
Carbon Fibre Reinforced Polymer ◽  
The Impact

The main aim of this work was the investigation of the possibility of replacing the heavy metallic meshes applied onto the composite structure in airplanes for lightning strike protection with a thin film of Tuball single-wall carbon nanotubes in the form of ultra-light, conductive paper. The Tuball paper studied contained 75 wt% or 90 wt% of carbon nanotubes and was applied on the top of carbon fibre reinforced polymer before fabrication of flat panels. First, the electrical conductivity, impact resistance and thermo-mechanical properties of modified laminates were measured and compared with the reference values. Then, flat panels with selected Tuball paper, expanded copper foil and reference panels were fabricated for lightning strike tests. The effectiveness of lightning strike protection was evaluated by using the ultrasonic phased-array technique. It was found that the introduction of Tuball paper on the laminates surface improved both the surface and the volume electrical conductivity by 8800% and 300%, respectively. The impact resistance was tested in two directions, perpendicular and parallel to the carbon fibres, and the values increased by 9.8% and 44%, respectively. The dynamic thermo-mechanical analysis showed higher stiffness and a slight increase in glass transition temperature of the modified laminates. Ultrasonic investigation after lightning strike tests showed that the effectiveness of Tuball paper is comparable to expanded copper foil.

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