Experimental Research on Medium Leakage of CFRP Laminates after Impact

2014 ◽  
Vol 633-634 ◽  
pp. 383-386
Author(s):  
A Ying Zhang ◽  
Dong Xing Zhang
Keyword(s):  
Impact Energy ◽  
Composite Laminates ◽  
Impact Damage ◽  
Energy Levels ◽  
Three Dimensional ◽  
Crater Depth ◽  
Damage Area ◽  
Cfrp Laminates ◽  
Impact Area ◽  
The Impact

The effects of thickness and impact energy on the medium leakage of composite laminates were discussed in this paper. Impact tests for the composite laminates with the size of 600 mm×700 mm with three different thicknesses were subjected to impact energy levels from 5 J to 40 J. The medium leakage and the damaged area were investigated according to different energy levels and stacking sequences. The damage area was evaluated by visual inspection and three-dimensional microscope. The experimental results reveal that the impact damage of CFRP laminates with three different thicknesses tends to be more severe as impact energy increases. The impact area and the crater depth increases with increasing impact energy. The impact area and the crater depth decreases with increasing thickness for the same impact energy.

Threshold of Impact Energy on the Medium Leakage of CFRP Laminates

2013 ◽  
Vol 395-396 ◽  
pp. 68-71
Author(s):  
A Ying Zhang ◽  
Zhi Jun Zhang ◽  
Zhen Jia ◽  
Ye Zhang ◽  
Dong Xing Zhang
Keyword(s):  
Impact Energy ◽  
Impact Damage ◽  
Energy Levels ◽  
Three Dimensional ◽  
Crater Depth ◽  
Damage Area ◽  
Cfrp Laminates ◽  
Impact Area ◽  
65 J ◽  
The Impact

The effects of the thickness and the impact energy on the medium leakage of CFRP laminates were discussed in this paper. Impact tests for CFRP laminates with the size of 600 mm×700 mm with three different thicknesses were subjected to impact energy levels from 5 J to 65 J. The medium leakage and the damaged area were investigated according to different energy levels and thicknesses. The damage area was evaluated by visual inspection and three-dimensional microscope. The experimental results reveal that the impact damage of CFRP laminates tends to be more severe as the impact energy increases, and the impact area and the crater depth increases with the increasing impact energy. For the same impact energy, the impact area and the crater depth decrease with the increasing thickness.

Experimental Research on the Effects of Dimension on the Impact Damage of CFRP Laminates

2013 ◽  
Vol 395-396 ◽  
pp. 64-67
Author(s):  
A Ying Zhang ◽  
Zhi Jun Zhang ◽  
Zhen Jia ◽  
Ye Zhang ◽  
Dong Xing Zhang
Keyword(s):  
Impact Energy ◽  
Composite Laminates ◽  
Impact Damage ◽  
Energy Levels ◽  
Three Dimensional ◽  
Crater Depth ◽  
Negative Effects ◽  
Cfrp Laminates ◽  
Length Increase ◽  
The Impact

The effects of thickness on the impact damage of composite laminates were discussed in this paper. Impact tests for the composite laminates with the size of 600 mm×700 mm with three different thicknesses were subjected to impact energy levels from 5 J to 40 J. The crater depth and matrix length were investigated according to different energy levels and different thicknesses. The impact damage was evaluated by visual inspection, three-dimensional microscope. The experimental results reveal that the crater depth and the crack length increase with the increasing impact energy. The thickness had the negative effects on the impact damage of the specimens at the same impact energy.

Experimental Research on the Impact Damage of Composite Laminates at Different Energies

2014 ◽  
Vol 887-888 ◽  
pp. 850-853
Author(s):  
A Ying Zhang ◽  
Han Xiong Lv ◽  
Ye Zhang ◽  
Dong Xing Zhang
Keyword(s):  
Crack Length ◽  
Experimental Research ◽  
Impact Energy ◽  
Composite Laminates ◽  
Impact Damage ◽  
Energy Levels ◽  
Cfrp Laminates ◽  
The Matrix ◽  
Impact Area ◽  
The Impact

The effects of the impact energy on the impact damage of CFRP laminates were studied in this paper. Impact tests for the CFRP laminates with the size of 600 mm×700 mm were subjected to different the impact energy levels from 5 J to 50 J. The matrix length was investigated according to different energy levels. The experimental results reveal that the crack length increases linearly with the increasing impact energy. The impact damage of CFRP laminates tends to be more severe as impact energy increases, and the impact area and crater depth increases with increasing impact energy. The surface of impact dent of specimen looks like W shape.

Experimental Research on CFRP Laminates with Different Impact Energy Levels

2014 ◽  
Vol 1030-1032 ◽  
pp. 1060-1063
Author(s):  
A Ying Zhang ◽  
Dong Xing Zhang
Keyword(s):  
Crack Length ◽  
Impact Energy ◽  
Impact Damage ◽  
Energy Levels ◽  
Three Dimensional ◽  
Fatigue Loading ◽  
Crater Depth ◽  
Cfrp Laminates ◽  
65 J ◽  
The Impact

The effects of thickness and impact energy on the impact damage of CFRP laminates were studied in this paper. Impact tests for the CFRP laminates with the size of 600 mm×700 mm with five different thicknesses were subjected to impact fatigue loading at different energy levels from 5 J to 65 J. The crater depth and matrix length were investigated according to different energy levels and different thicknesses. The impact damage was evaluated by visual inspection, three-dimensional microscope. The experimental results reveal that the crater depth and the crack length increase with the increasing impact energy. For the same impact energy, the crater depth and the crack length decreased with the increasing thickness of specimens.

Experimental investigation on a fully thermoplastic composite subjected to repeated impacts

2019 ◽  
Vol 233 (19-20) ◽  
pp. 6985-7002
Author(s):  
S Boria ◽  
A Scattina ◽  
G Belingardi
Keyword(s):  
Composite Laminates ◽  
Mechanical Performance ◽  
Impact Damage ◽  
Energy Levels ◽  
Thermoplastic Composite ◽  
Thermoplastic Composites ◽  
Low Velocity ◽  
Repeated Impacts ◽  
Structural Parts ◽  
The Impact

In the last years, the spread of composite laminates into the engineering sectors was observed; the main reason lies in higher values of strength/weight and stiffness/weight ratios with respect to conventional materials. Firstly, the attention was focused on fibres reinforced with thermosetting matrix. Then, the necessity to move towards low density and recyclable solutions has implied the development of composites made with thermoplastic matrix. Even if the first application of thermoplastic composites can be found into no structural parts, the replacement of metallic structural parts with such material in areas potentially subjected to impact has become worthy of investigation. Depending on the field of application and on the design geometry, in fact, some components can be subjected to repeated impacts at localized sites either during fabrication, activities of routine maintenance or during service conditions. When composite material was adopted, even though the impact damage associated to the single impact event can be slight, the accumulation of the damage over time may seriously weaken the mechanical performance of the structure. In this overview, the capability of energy absorption of a new composite completely made of thermoplastic material was investigated. This material was able to combine two conflicting requirements: the recyclability and the lightweight. In particular, repeated impacts at low velocity, on self-reinforced laminates made of polypropylene (PP), were conducted by experimental drop dart tests. Repeated impacts up to the perforation or up to 40 times were performed. In the analysis, three different energy levels and three different values of the laminate thicknesses were considered in order to analyse the damage behaviour under various experimental configurations. A visual observation of the impacted specimens was done, in order to evaluate the damage progression. Moreover, the trend of the peak force interchanged between specimen and dart and the evolution of both the absorbed energy and of the bending stiffness with the impacts number were studied. The results pointed out that the maximum load and the stiffness of the specimens tended to grow increasing the number of the repeated impacts. Such trend is opposite compared to the previous results obtained by other researchers using thermosetting composites.

Compressive Strength of CCF300/QY8911 Composite Laminates with LVI Damage

2012 ◽  
Vol 583 ◽  
pp. 203-206
Author(s):  
Hai Ming Hong ◽  
Ming Li ◽  
Jian Yu Zhang ◽  
Yi Ning Zhang
Keyword(s):  
Compressive Strength ◽  
Impact Energy ◽  
Composite Laminates ◽  
Inflection Point ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Damage Area ◽  
Compressive Performance ◽  
The Impact ◽  
Dent Depth

A series of low-velocity impact tests and residual compressive strength tests after impacts on CCF300/QY8911 composite materials were carried out to study the mechanism of compression failure of the laminates after low-velocity impact. The curves of impact energy verse dent depth and impact energy verse the damage area was obtained. And the residual compressive strength and stiffness after impact verse damage parameters were analyzed. The results showed that when the impact energy exceeded the inflection point, as the impact energy increased, the dent depth on the impacted surface of the laminates notably increased while the damage area of the internal layers merely increased slowly. If the impact energy was continued to increase, the expansion of the laminates' internal damage mainly consisted of fiber breaks. The main reason for the decrease in compressive performance of composite laminates was inside delamination between layers, while in the case in which impact energy exceeded the inflection point, there were no obvious changes in delamination damage area for different energy, so the residual compressive performance kept almost stable.

scholarly journals Impact Resistance of Plain and Twill Fabric in GFRP Measured by Active Thermography

2018 ◽  
Vol 27 (5) ◽  
pp. 096369351802700 ◽  
Author(s):  
G. Strugala ◽  
M. Landowski ◽  
M. Zaremba ◽  
J. Turowski ◽  
M. Szkodo
Keyword(s):  
Impact Energy ◽  
Impact Damage ◽  
Impact Resistance ◽  
Damage Area ◽  
Plain Weave ◽  
Active Thermography ◽  
Glass Fibre Reinforced Polymer ◽  
Glass Fibre Reinforced ◽  
The Impact ◽  
Twill Weave

This paper discusses the impact resistance of glass-fibre reinforced polymer (GFRP) composites depending on the type of reinforcement – plain or twill weave. The values of impact energy were: 3J, 10J and 15J. Specimens featuring twill weave transferred higher force during the impact as compared with plain weave specimens. It was observed that an increase of impact energy was accompanied by an increase of the disproportion in transferred forces, in favour of twill weave specimens. Impact damage (in both types of weave) occurring as a result of 3J impact was undetectable with active thermography method. The damage area measured by means of active thermography for impact energy values equal to 10J and 15J proved that the type of reinforcement significantly influences the impact resistance of a composite. This has been justified by smaller damage areas with high spot intensity of damage in plain weave specimens and highly dispersed damage with lower intensity in twill weave specimens.

scholarly journals Analysis on the impact response of fiber-reinforced composite laminates: an emphasis on the FEM simulation

2019 ◽  
Vol 26 (1) ◽  
pp. 1-11
Author(s):  
Jian He ◽  
Liang He ◽  
Bin Yang
Keyword(s):  
Energy Absorption ◽  
Impact Energy ◽  
Composite Laminates ◽  
Mechanical Response ◽  
Adhesive Layer ◽  
Laminated Plates ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Damage Area ◽  
The Impact

AbstractThe effects of units, material parameters, and constitutive relationships on the dynamic mechanical response of composite laminates subjected to high- and low-velocity impacts were investigated. Additionally, the role of impact or shape, including hemispherical, flat, and conical, on the damage area of the adhesive layer and displacement of the center of the laminated plates was investigated. The results show that the energy absorption of composite laminates increases with impact velocity, and specific energy absorption changes with the density of the contact surface, which is affected by ply thickness. Moreover, the target energy absorption decreases with increasing layer angle. Under a low-velocity impact, the maximum contact force, damage area of the adhesive layer, and displacement of the center of the laminated plate increase as the impact energy increases, thus showing that impact energy is not directly related to contact duration and energy absorption of composite laminates. The results of different geometric shapes show that the damage area of the adhesive layer and the displacement of the center of the laminated plates are largest for a conical impactor and smallest for a flat impactor.

scholarly journals Experimental and numerical study of the response to various impact energy levels for composite sandwich plates with different face thicknesses

2019 ◽  
Vol 21 (5) ◽  
pp. 1654-1682
Author(s):  
Moeen S Rajput ◽  
Magnus Burman ◽  
Fredrik Forsberg ◽  
Stefan Hallström
Keyword(s):  
Impact Energy ◽  
Impact Damage ◽  
Energy Levels ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Absorbed Energy ◽  
Low Velocity ◽  
Composite Sandwich ◽  
The Impact ◽  
Dent Depth

Composite sandwich structures find wide application in the aerospace sector thanks to their lightweight characteristics. However, composite structures are highly susceptible to low-velocity impact damage and therefore thorough characterization of the impact response and damage process for the used material configurations is necessary. The present study investigates the effect of face-sheet thickness on the impact response and damage mechanisms, experimentally and numerically. A uni-directional, non-crimp fabric is used as reinforcement in the face-sheets, and a closed cell Rohacell 200 Hero polymer foam is used as core material. Low-velocity impact tests are performed in a novel instrumented drop-weight rig that is able to capture the true impact response. A range of impact energies are initially utilized in order to identify when low level damage (LLD), barely visible impact damage (BVID) and visible impact damage (VID) occur. A thorough fractography investigation is performed to characterize the impact damage using both destructive and non-destructive testing. The damage from the impacts in terms of dent depth, peak contact force, deflection and absorbed energy is measured. The results show bilinear responses in dent depth vs. impact energy and absorbed energy vs. impact energy. It is found than the BVID energy works well as an indication for the onset of excessive damage. Fractography reveals that there is a failure mode shift between the LLD and the VID energy levels, and that delaminations predominantly grow along the fiber direction and rotate in a spiral pattern through the thickness, following the laminate ply orientations. Finally, a progressive damage finite element model is developed to simulate both the impact response and the delamination extent, incorporating both intra-laminar and inter-laminar damage modes. The simulation shows good agreement with the experiments.

Validity of Several NDT Methods on Low Velocity Impact Damage Evaluation of 2-Dimensional Plain Woven C/SiC Composites

2012 ◽  
Vol 581-582 ◽  
pp. 764-767 ◽  
Author(s):  
Sheng Shan Li ◽  
Xiao Yan Tong ◽  
Lei Jiang Yao ◽  
Bin Li
Keyword(s):  
Impact Energy ◽  
Thermal Imaging ◽  
Impact Damage ◽  
Low Velocity Impact ◽  
Detection Methods ◽  
Low Velocity ◽  
Infrared Thermal Imaging ◽  
Velocity Impact ◽  
Damage Area ◽  
The Impact

An experimental study was carried out to study the low-velocity impact characteristics and the influence of impact energy on the damage of plain woven carbon fiber reinforced silicon carbide composite. Visual, ultrasonic scanning, X-ray, industrial CT and infrared thermal imaging were then utilized respectively for Nondestructive Testing of the test specimens after impact test. The results show that the material damage area increase significantly with the increase of the impact energy. But as the specimen is run through, when the impact energy comes to12J, the damage area decrease. Compare the changing curves of the damage areas obtained by different detection methods, we can find that the changing trends of the damage areas obtained by ultrasonic C-scan and infrared thermal imaging are the same with the impact energies, indicating that the damage of the specimen are more credible by the two methods.

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