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.

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 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.

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.

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.

scholarly journals Effect of Fibre Orientation on Impact Damage Resistance of S2/FM94 Glass Fibre Composites for Aerospace Applications: An Experimental Evaluation and Numerical Validation

Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 95
Author(s):  
Khaled Giasin ◽  
Hom N. Dhakal ◽  
Carol A. Featheroson ◽  
Danil Yurievich Pimenov ◽  
Colin Lupton ◽  
...  
Keyword(s):  
Impact Energy ◽  
Glass Fibre ◽  
Fibre Orientation ◽  
Impact Damage ◽  
Energy Levels ◽  
Shear Stresses ◽  
Fe Model ◽  
Damage Initiation ◽  
Aerospace Applications ◽  
The Impact

This study aims to investigate the influence of fibre orientation and varied incident energy levels on the impact-induced damage of S2/FM94, a kind of aerospace glass fibre epoxy/composite regularly used in aircraft components and often subjected to low-velocity impact loadings. Effects of varying parameters on the impact resistance behaviour and damage modes are evaluated experimentally and numerically. Laminates fabricated with four different fibre orientations 0/90/+45/−458s, 0/90/90/08s, +45/−4516s, and  032 were impacted using three energy levels. Experimental results showed that plates with unidirectional fibre orientation failed due to shear stresses, while no penetration occurred for the 0/90/90/08s and +45/−4516s plates due to the energy transfer back to the plate at the point of maximum displacement. The impact energy and resulting damage were modelled using Abaqus/Explicit. The Finite Element (FE) results could accurately predict the maximum impact load on the plates with an accuracy of 0.52% to 13%. The FE model was also able to predict the onset of damage initiation, evolution, and the subsequent reduction of the strength of the impacted laminates. The results obtained on the relationship of fibre geometry and varying incident impact energy on the impact damage modes can provide design guidance of S2/FM94 glass composites for aerospace applications where impact toughness is critical.

Numerical Investigation of the Damage Mechanism of Offshore Pipeline Impacted by the Lump-Shaped Falling Object

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Han Zhang ◽  
Jie Zhang ◽  
Ruinan Lin ◽  
Yangjie Li
Keyword(s):  
Impact Energy ◽  
Impact Damage ◽  
Three Dimensional ◽  
Damage Mechanism ◽  
Thickness Ratio ◽  
Mechanism Analysis ◽  
Stress Concentrations ◽  
Offshore Pipeline ◽  
Global Deformation ◽  
The Impact

Abstract Damage mechanism analysis of the exposed offshore pipeline impacted by lump-shaped falling objects plays a significant role in offshore pipeline design, inspection, maintenance, and protection. A series of three-dimensional (3D) coupling models are established and simulated to investigate mechanical behaviors and responses of exposed offshore pipelines impacted by lump-shaped falling objects. The effects of both offshore pipeline parameters and lump-shaped falling object parameters were discussed under the joint action of internal pressure and external seawater pressure. The results demonstrate that seabed soil could absorb partial impact energy and act as a cushion. Indentation on the pipeline top and stress concentrations on the pipeline bottom starts to appear when the impact velocity is larger than 10 m/s and 14 m/s, respectively. The critical impact energy before pipeline failure is around 9733.339 J. A variation in contact area has a noticeable influence on the dent depth, but a slight influence on the global deformation. An increase in pressure difference mitigates the impact damage. The depression rate increases with the rise of the radius-thickness ratio, and the most severe plastic deformation occurs when the radius-thickness ratio is 40. Besides, the eccentric distance is an essential factor influencing the damage mechanism of the offshore pipeline.

scholarly journals Crushing Susceptibility of Vetch Seeds Under Impact Loading

2017 ◽  
Vol 50 (4) ◽  
pp. 5-16
Author(s):  
F. Shahbazi
Keyword(s):  
Moisture Content ◽  
Impact Energy ◽  
Impact Loading ◽  
Impact Damage ◽  
Mechanical Damage ◽  
Seed Moisture Content ◽  
Mean Values ◽  
Seed Moisture ◽  
Mathematical Relationships ◽  
The Impact

AbstractMechanical damage of seeds due to harvest, handling and other process is an important factor that affects the quality and quaintly of seeds. The objective of this research was to determine the effects of moisture content and the impact energy on the breakage susceptibility of vetch seeds. The experiments were conducted at moisture contents of 7.57 to 25% (wet basis) and at the impact energies of 0.1, 0.2 and 0.3 J, using an impact damage assessment device. The results showed that impact energy, moisture content, and the interaction effects of these two variables significantly influenced the percentage breakage in vetch seeds (p<0.01). Increasing the impact energy from 0.1 to 0.3 J caused a significant increase in the mean values of seeds breakage from 41.69 to 78.67%. It was found that the relation between vetch seeds moisture content and seeds breakage was non-linear, and the extent of damaged seeds decreased significantlyas a polynomial (from 92.47 to 33.56%) with increasing moisture (from 7.57 to 17.5%) and reached a minimum at moisture level of about 17.5%. Further increase in seed moisture, however, caused an increase in the amount of seeds breakage. Mathematical relationships composed of seed moisture content and impact energy, were developed for accurately description the percentage breakage of vetch seeds under impact loading. It was found that the models have provided satisfactory results over the whole set of values for the dependent variable.

Impact Damage Detection in GFRP Laminates through Ultrasonic Imaging

2012 ◽  
Vol 585 ◽  
pp. 337-341 ◽  
Author(s):  
H. Rama Murthy Naik ◽  
J. Jerald ◽  
N. Rajesh Mathivanan
Keyword(s):  
Impact Energy ◽  
Ultrasonic Testing ◽  
Energy Levels ◽  
Low Velocity Impact ◽  
Image Processing Technique ◽  
Sound Waves ◽  
Low Velocity ◽  
Immersion Method ◽  
Pulse Echo ◽  
The Impact

Composite materials are increasingly used in aerospace, naval and automotive vehicles due to their high specific strength and stiffness. In the area of Non destructive testing, ultrasonic C-scans are used frequently to detect defects in composite components caused during fabrication and damage resulting from service conditions. Ultrasonic testing uses transmission of high frequency sound waves into a material to detect imperfections or to locate changes in material properties. The most commonly used ultrasonic testing technique is pulse echo and through transmission wherein sound is introduced into a test object and reflections (echoes) are returned to a receiver from internal imperfections. Under low-velocity impact loading delaminating is observed to be a major failure mode. This report presents the use of above two techniques to detect the damage in glass fiber reinforced plastic (GFRP) laminates. Pulse echo is used to locate the exact position of damage and through transmission is used to know the magnitude of damage in composite. This paper work will be carried out on two different thicknesses and at impact energy levels varying from 7 to 53J. The ensuring delamination damage will be determined by ultrasonic C-scans using the pulse-echo immersion method for through transmission. Delamination areas were quantified accurately by processing the raw image data using a digital image processing technique. Based on the data obtained, correlation will be established between the delamination area and the impact energy.

Damage Development in CFRP Laminates under Impact Loading

2006 ◽  
Vol 326-328 ◽  
pp. 1833-1836 ◽  
Author(s):  
Seung Min Jang ◽  
Tadaharu Adachi ◽  
Akihiko Yamaji
Keyword(s):  
Impact Damage ◽  
Stacking Sequence ◽  
Absorbed Energy ◽  
Damage Development ◽  
Damage Resistance ◽  
Cfrp Laminates ◽  
Impact Tester ◽  
Weight Impact ◽  
The Impact ◽  
Delamination Area

The development characteristics of impact-induced damage in carbon-fiber-reinforcedplastics (CFRP) laminates were experimentally studied using a drop-weight impact tester. Five types of CFRP laminates were used to investigate the effect of stacking sequences and thicknesses. The efficiency of absorbed energy to impact energy was different for CFRP laminates with different stacking sequences or thicknesses. The DA/AE ratio of delamination area (DA) to absorbed energy (AE) was almost the same for CFRP laminates with the same stacking sequence regardless of the thickness. We found that the DA/AE ratio could be used as a parameter to characterize the impact damage resistance in CFRP laminates with different stacking sequences.

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