scholarly journals Influence of the stacking sequence on the low-energy impact resistance of flax/PA11 composite

2019 ◽  
Vol 53 (22) ◽  
pp. 3187-3198 ◽  
Author(s):  
Yann Lebaupin ◽  
Thuy-Quynh T Hoang ◽  
Michaël Chauvin ◽  
Fabienne Touchard
Keyword(s):  
Impact Load ◽  
Peak Load ◽  
Composite Plates ◽  
Low Energy ◽  
Impact Behavior ◽  
Stacking Sequence ◽  
Polyamide 11 ◽  
Energy Impact ◽  
Isotropic Composite ◽  
The Impact

In this paper, the low-energy impact behavior of a fully biobased composite made of bio-sourced polyamide 11 resin reinforced with flax fibers was investigated. Different composite laminates were studied in order to determine the stacking sequence effects on the impact behavior of these composites. Four stacking sequences were manufactured: unidirectional [0°]8, cross-ply [0°/90°]2s, sandwich-like [02°/902°]s and quasi-isotropic [45°/0/−45°/90°]s. A low impact energy of 3.6 J was applied on these laminates by means of a drop weight impact tower. The impact properties of these lay-ups were ascertained by analysing the impact load history, the maximal displacement of the impactor and the absorbed energy. Damage after impact was further assessed by visual inspections, topographic measurements, C-scan and X-ray micro-tomography observations. The results show that impact damage of composite plates is highly influenced by fiber orientation. The impact test data are in good agreement with damage analysis after impact and indicate that stacking plies in the same orientation lead to a larger induced damage, which is responsible for energy dissipation. The quasi-isotropic composite has the smallest induced damage and the highest peak load. Otherwise, the sandwich-like sequence shows the lowest peak load, the highest energy absorption and significant induced damage. Therefore, it is necessary to choose the most suitable lay-up, in terms of impact behavior, for each considered industrial application.

scholarly journals Effect of Fibre Architecture on Impact Response of Glass-Aluminium Fibres Metal Laminates (FML)

2019 ◽  
Vol 9 (1) ◽  
pp. 5639-5645
Keyword(s):  
Glass Fibre ◽  
Impact Load ◽  
Peak Load ◽  
Matrix Cracking ◽  
Impact Behavior ◽  
Drop Weight ◽  
Glass Fibre Reinforced Polymer ◽  
Glass Fibre Reinforced ◽  
Weight Impact ◽  
The Impact

This paper investigates the drop weight impact behavior of glass fibre-aluminum (GFRP-AL FML) composites. The purpose of the research is to study the effect of different type of glass fibres architecture, i.e woven and unidirectional, with existence Al sheet in the middle of the glass fibre reinforced polymer composites (GFRP). The impact behaviour of these GFRP and GFRP-AL FMLs was investigated using a drop-weight impact tower at three different energy level, which are 10J, 20J and 30J. The Load - deflection curves were used to measure the absorbed energy. The results showed that the woven type of GFRP exhibited the highest peak load but lowest deflection thus reducing the total energy absorbed. In contrast, the unidirectional types of GFRP possessed the lowest peak load and highest deflection, which results in the highest energy absorbed. For the GFRP-AL FML composites, the energy absorbed obtained almost similar for both woven and unidirectional types. This is may be due to poor adhesion between the GFRP and Al sheet, thus make both materials separated and delaminated when subjected to impact load. The optical analysis proved that the GFRP-AL debonding, fibres breakage, fibres delamination and matrix cracking occurred during the impact loading. These are the main impact energy –absorption mechanisms involved during the test.

Effects of Wall Thickness and Crush Initiators Position under Experimental Drop Test on Square Tubes

2017 ◽  
Vol 865 ◽  
pp. 612-618 ◽  
Author(s):  
M. Malawat ◽  
Jos Istiyanto ◽  
D.A. Sumarsono
Keyword(s):  
Energy Absorption ◽  
Tube Wall ◽  
Impact Load ◽  
Peak Load ◽  
Load Force ◽  
Drop Height ◽  
Thin Walled ◽  
The Impact ◽  
Initial Peak ◽  
Load Mass

Crush initiators are the weakest points to reduce initial peak load force with significant energy absorption ability. The objective of this paper is to study the effects of square tube thickness and crush initiators position for impact energy absorber (IEA) performance on thin-walled square tubes. Two square tubes having thickness about 0.6 mm (specimen code A) and 1 mm (specimen Code C) were tested under dynamic load. The crushing initiator is designed around the shape of the tube wall and has eight holes with a fixed diameter of 6.5 mm. In the experiment, the crushing initiator was determined at 5 different locations on the specimen wall. These locations are 10 mm, 20 mm. 30 mm, 40 mm, and 50 mm measured from the initial collision position of the specimen tested. The impact load mass was about 80 kg and had a drop height of about 1.5 m. Using the simulation program of the LabVIEW Professional Development System 2011 and National Instrument (NI) 9234 software equipped with data acquisition hardware NI cDAQ-9174 the signal from the load cell was sent to a computer. By controlling the thickness of the thin-walled square tube, the peak loading force can be decreased by approximately 56.75% and energy absorption ability of IEA can be increased approximately to 11.83%. By using different thin-walled square tube can produce different best crush initiators position with the lowest peak load force.

The Structural Impact Characteristics of Indonesian Railway Vehicle

2004 ◽  
Vol 261-263 ◽  
pp. 337-344 ◽  
Author(s):  
Ign Wiratmaja Puja ◽  
T. Hardono ◽  
Khalid ◽  
M.F. Adziman
Keyword(s):  
Impact Energy ◽  
Impact Load ◽  
Rigid Wall ◽  
Impact Behavior ◽  
Railway Vehicle ◽  
Railway Transportation ◽  
Passenger Cars ◽  
Vehicle Structure ◽  
Structural Impact ◽  
The Impact

The Indonesian railway transportation has adventages in term of capacity, efficiency, trafic, and safety compared to the other types of land transportations. At present, the Indonesian Railway Company has 519 locomotives, and 1643 passenger cars, that transport about 184 million man-trip each year[1,2]. Unfortunately, the rate of train collisions in Indonesian railway system was very high. In the last ten years, 2352 train accidents have happened which claimed 997 lives and left 2638 people injured. The record shows that 110 of those accidents were train to train collisions[1]. This paper consider the structural impact behavior of Indonesian passenger railway car subject to collision forces. This characteristic is very important parameter for passenger protection during the course of collision[3-5]. The vehicle structure should be able to absorb the huge impact energy or impact force to ensure the passenger safety[6-9]. The impact energy of cars-train is evaluated using the principle of multibody dynamics[10,11]. The vehicle structure under impact load is analyzed using the finite element method. The principal of symmetry is adopted, so the collision scene could be simulated as collision between the vehicle with a rigid wall. The analysis result shows that the structure is collapse at the passenger area (saloon) which is in agreement with the real collision. Modification is proposed to protect the passenger area by introducing crush zone area and impact energy absorber.

scholarly journals Influence of Voids Ratio on Impact Behavior of Circular Ferrocement Slabs

2019 ◽  
Vol 5 (1) ◽  
pp. 117
Author(s):  
Muyasser M. Jomaah ◽  
Muna Zead Baraa
Keyword(s):  
Impact Energy ◽  
Structural Strength ◽  
Impact Load ◽  
Low Cost ◽  
Load Test ◽  
Wire Mesh ◽  
Impact Behavior ◽  
Experimental Program ◽  
Test Results ◽  
The Impact

The objective of using materials is to fully utilize the properties of these materials in order to obtain the best performance of the structure. The merits of material are based on many factors like, workability, structural strength, durability and low cost. Ferrocement is an excellent construction system. This paper studies the behavior of ferrocement circular slabs under impact load. The experimental program include testing four sime fixed supported ferrocement circular slabs of 800mm diameter and 50mm thickness. The Influence of the use of styropor voids was investigated in different ratios (24% and 48%) and a number of wire mesh layers four and six layers. Impact load test results revealed that increasing number of wire mesh from 4 to 6 led to an increase in the impact energy for first crack by (41.991% ,37.62%) respectively when using voids ratio by (24% and 48%) respectively and impact energy for full perforation by (21.7% and 9.94%) respectively when using voids ratio by (24% and 48%) respectively. Ferrocement circular slabs are used in construction fields such as roofs, tanks, manholes, etc.

scholarly journals Enhanced Impact-Resistance of Aeronautical Quasi-Isotropic Composite Plates Through Diffused Water Molecules in Epoxy

2020 ◽  
Author(s):  
Furqan Ahmad ◽  
Fethi Abbassi ◽  
Mazhar Ul-Islam ◽  
Frédéric JACQUEMIN ◽  
Jung-Wuk Hong
Keyword(s):  
Carbon Fiber ◽  
Impact Resistance ◽  
Composite Plates ◽  
Hot Water ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Segmental Mobility ◽  
Impact Tests ◽  
Isotropic Composite ◽  
The Impact

Abstract In order to elucidate the hygroscopic effects on impact-resistance of carbon fiber/epoxy quasi-isotropic composite plates, low-velocity impact tests are conducted on dry and hygroscopically conditioned plates, respectively, under identical configurations. For the impact tests, plates were immersed in the hot water at 80 °C to absorb a different amount of moisture content (MC). Experimental results reveal that the presence of the MC plays a pivotal role by improving the impact-resistance of composite plates. Plates with higher percentage of MC could behave elastically to a larger strain, yielding larger deflection under impact loading. From SEM fractographies, it is observed that small disbanding grows at the interface of epoxy and carbon fiber due to absorbed MC. After absorbing MC, most of impact enegy is dissipated in hygroscopic conditioned composite plates throught elastic deformation and overall less damage is induced in wet composite plates compare to the dry plate. We can postulate that the presence of MC increases the elastic limit as well as ductility of the epoxy by promoting chain segmental mobility of the polymer molecules, which eventually leads to the enhancement of the impact-resistance of wet quasi-isotropic composite plates in comparison with the dry plate.

scholarly journals Parameter Analysis on the Anti-Impact Behavior of Pcfst Columns under Lateral Impact Load

2018 ◽  
Vol 206 ◽  
pp. 01020
Author(s):  
W Xu ◽  
A Z Zhu ◽  
K Gao
Keyword(s):  
Yield Strength ◽  
Impact Energy ◽  
Impact Load ◽  
Parameter Analysis ◽  
Impact Behavior ◽  
Lateral Impact ◽  
Fea Model ◽  
Filling Height ◽  
Concrete Filling ◽  
The Impact

Concrete-filled steel tubular (CFST) structures have been widel y used in civil engineering structures, due to its good behaviors under both static and dynamic loads. In this paper, numerical studies were carried out to investigate the anti-impact behavior of partially concrete-filled steel tubular (PCFST) columns under lateral impact loads. Finite element analysis (FEA) model was established using ABAQUS. To validate the FEA model, the numerical results were compared with experimental results. Moreover, parameter analysis was carried out to further study the anti-impact behaviors of the PCFST columns. The concrete filling height, the impact energy, the impact direction, and the yield strength of steel were the main parameters considered in this study. The dynamic responses under the impact load, including the impact force, the failure mode, and the displacement response, were all analyzed. The results of parameter analysis showed that the anti-impact behaviors of the PCFST columns significantly increased when the concrete filling height or the yield strength of steel increased greatly. The impact energy and direction also greatly affected the anti-impact behaviors of the PCFST columns.

Impact Damage Monitoring in Composite Plates

2004 ◽  
Author(s):  
Frank J. Shih ◽  
Sauvik Banerjee ◽  
Ajit K. Mal
Keyword(s):  
Impact Load ◽  
Impact Damage ◽  
Composite Plates ◽  
Impact Testing ◽  
Far Field ◽  
Internal Damage ◽  
Distributed Sensors ◽  
Surface Motion ◽  
Impact Monitoring ◽  
The Impact

This paper is concerned with the real-time detection of internal damage in composite structural components during impact using the far-field surface motion generated by these events. Impact tests are carried out on graphite epoxy composite plates using an instrumented impact testing system. Contact force and surface motion are measured at several locations on the plate surface. The far-field surface motions, both flexural and extensional waves in the composite plate, are modeled using both approximate and exact solution methods. Postimpact test were performed to determine the extent of internal damage caused by the impact load. Further research on the detection method can lead to the development of a viable impact monitoring system for composite aerospace structures using distributed sensors.

scholarly journals Enhanced impact-resistance of aeronautical quasi-isotropic composite plates through diffused water molecules in epoxy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Furqan Ahmad ◽  
Fethi Abbassi ◽  
Mazhar Ul-Islam ◽  
Frédéric Jacquemin ◽  
Jung-Wuk Hong
Keyword(s):  
Carbon Fiber ◽  
Impact Resistance ◽  
Composite Plates ◽  
Hot Water ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Segmental Mobility ◽  
Impact Tests ◽  
Isotropic Composite ◽  
The Impact

AbstractIn order to elucidate the hygroscopic effects on impact-resistance of carbon fiber/epoxy quasi-isotropic composite plates, low-velocity impact tests are conducted on dry and hygroscopically conditioned plates, respectively, under identical configurations. For the impact tests, plates were immersed in the hot water at 80 °C to absorb a different amount of moisture content (MC). Experimental results reveal that the presence of the MC plays a pivotal role by improving the impact-resistance of composite plates. Plates with higher percentage of MC could behave elastically to a larger strain, yielding larger deflection under impact loading. From SEM fractographies, it is observed that small disbanding grows at the interface of epoxy and carbon fiber due to absorbed MC. After absorbing MC, most of impact energy is dissipated in hygroscopic conditioned composite plates through elastic deformation and overall less damage is induced in wet composite plates compare to the dry plate. We can postulate that the presence of MC increases the elastic limit as well as ductility of the epoxy by promoting chain segmental mobility of the polymer molecules, which eventually leads to the enhancement of the impact-resistance of wet quasi-isotropic composite plates in comparison with the dry plate.

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