Mechanical and low-velocity impact properties of epoxy-composite beams reinforced by MWCNTs

2018 ◽  
Vol 53 (5) ◽  
pp. 693-705 ◽  
Author(s):  
Mehdi Ranjbar ◽  
Saeed Feli
Keyword(s):  
Tensile Strength ◽  
Young’S Modulus ◽  
Contact Force ◽  
Young's Modulus ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Impact Properties ◽  
Velocity Impact ◽  
Pure Epoxy ◽  
The Impact

The effect of different weight percentages (wt.%) of MWCNTs includes 0, 0.17, 0.34 and 0.51% on the mechanical and low-velocity impact properties are presented on the example of the pure epoxy and epoxy/fiberglass composites beams. A sonication technique is used to disperse MWCNTs in the epoxy network and the nanocomposite beams are fabricated using hand lay-up technique. In tensile tests, the value of Young’s modulus, tensile strength and strain at break are reported. In the low-velocity impact tests on the MWCNTs/fiberglass/epoxy, the time-history response of contact force, displacement and velocity of the impactor and indentation and displacement of the beam are measured and presented. The results show that compared to pure epoxy, Young’s modulus and tensile strength of epoxy/MWCNTs are increased 21.98% and 58.32% at 0.34 wt.% of CNTs, respectively, and raised 1.05 and 1.17 times at 0.17 wt.% of CNTs for the epoxy/fiberglass/MWCNTs, respectively. It is observed that the excellent improvement in the impact properties is achieved for 0.34 wt.% of CNTs. A series of polynomial formulations as a function of wt.% of CNTs are proposed to calculate the Young’s modulus, peak contact force and maximum beam deflection at the impact position.

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).

scholarly journals The Low Velocity Impact Properties of Pandanus Fiber Composites

2017 ◽  
Vol 895 ◽  
pp. 56-60 ◽  
Author(s):  
Hoo Tien Nicholas Kuan ◽  
Meng Chuen Lee ◽  
Amir Azam Khan ◽  
Marini Sawawi
Keyword(s):  
Impact Loading ◽  
Volume Fraction ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Impact Properties ◽  
Velocity Impact ◽  
Impact Performance ◽  
Biodegradable Composites ◽  
Penetration Tests ◽  
The Impact

The impact properties of biodegradable Pandanus atrocarpus composite laminate is studied. Laminate samples were fabricated using a hot compression molding technique with high-density polyethylene and extracted Pandanus fiber. Pandanus composites were tested under impact loading in order to study their relative impact performance. Under low velocity impact loading, Pandanus fiber laminates offered an excellent resistance to impact penetration. Tests have shown that increasing the volume fraction of Pandanus fiber can enhance the toughness of the composite. The biodegradable composites imply attractive properties that may be accessible for use in engineering sectors.

Experimental and numerical behaviors of GFRP laminates under low velocity impact

2020 ◽  
Vol 54 (21) ◽  
pp. 2999-3007
Author(s):  
Hüseyin E Yalkın ◽  
Ramazan Karakuzu ◽  
Tuba Alpyıldız
Keyword(s):  
Contact Force ◽  
Impact Energy ◽  
Damage Mechanics ◽  
Matrix Material ◽  
Impact Testing ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Wide Range ◽  
The Impact

The aim of the study is to investigate the behavior of laminated composites under low velocity impact both experimentally and numerically. With this aim, the effects of wide range impact energy values between 10 J and 60 J were evaluated experimentally and numerically for the laminate of [±45/(0/90)2]S oriented unidirectional E-glass as reinforcing material and epoxy resin for matrix material. Different impactor velocities were used to maintain the impact energy values and experimental impact tests were generated with drop weight impact testing machine at room temperature. Numerical simulations were performed using LS-DYNA finite element analysis software with a continuum damage mechanics-based material model MAT058. Contact force between impactor and laminate, and transverse deflection at the center of laminate results were obtained as a function of time and used to plot contact force–time curves, contact force–deflection curves and absorbed energy-impact energy curves. Also, delamination area was examined. Finally, numerical results were compared with experimental results and a good correlation between them was observed.

Investigation of nano-hybridization effects on low velocity impact behaviors of basalt fiber reinforced composites

2020 ◽  
pp. 002199832094964
Author(s):  
İbrahim Demirci ◽  
Ahmet Avcı ◽  
Mehmet Turan Demirci
Keyword(s):  
Tensile Strength ◽  
Epoxy Composites ◽  
Low Velocity Impact ◽  
Maximum Force ◽  
Fracture Mechanisms ◽  
Fiber Reinforced ◽  
Epoxy Nanocomposites ◽  
Low Velocity ◽  
Velocity Impact ◽  
The Impact

In general the nanoparticles increase the mechanical and impact behaviors of fiber reinforced polymer based composites. However, the effects of the hybridization of nanoparticles and their reasons over the nano scale fracture mechanisms have not been adequately studied for fiber reinforced composites. In this study, the low velocity impact responses and the mechanical behaviors were investigated for 4%wt. SiO2 nanoparticles filled BFR/Epoxy nanocomposites, 0.5%wt. MWCNTs filled BFR/Epoxy nanocomposites, 4%wt. SiO2 nanoparticles and 0.5%wt. MWCNTs nano-hybrid filled BFR/Epoxy nanocomposites and unfilled BFR/Epoxy composites. The tensile and low velocity impact tests at 10 J and 20 J of energy levels were applied to nanoparticles, nano-hybrid and unfilled BFR/Epoxy composites in order to define the effects of nanoparticles and nano-hybrid particles on the impact and mechanical features according to in accordance with ASTM D3039/D3039M-14 and ASTM D7136/7136M standards. It was observed that SiO2 nanoparticles addition to BFR/Epoxy for both 10 J and 20 J showed the highest tensile strength, maximum force, rebound energy and the lowest displacements and absorbed energy. SiO2+MWCNTs nano-hybrid addition to BFR/Epoxy improved higher low velocity impact responses and tensile strength than MWCNTs addition. The specimens of unfilled BFR/Epoxy composites showed the lowest tensile strength and maximum force and the highest maximum force, displacements and absorbed energy. Microscope and SEM analyses demonstrated that minimum failures like fiber breakages, delamination and debonding were observed by filling SiO2 nanoparticles provided the nano scale fracture mechanisms. In addition MWCNTs hybridization with SiO2 nanoparticles minimizes negative effects of MWCNTs micro size length and improved the impact and mechanical behaviors.

Low-velocity impact behaviour of titanium honeycomb sandwich structures

2017 ◽  
Vol 20 (8) ◽  
pp. 1009-1027 ◽  
Author(s):  
Zonghong Xie ◽  
Wei Zhao ◽  
Xinnian Wang ◽  
Jiutao Hang ◽  
Xishan Yue ◽  
...  
Keyword(s):  
Contact Force ◽  
Sandwich Structures ◽  
Impact Damage ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Honeycomb Sandwich ◽  
The Impact ◽  
Maximum Contact ◽  
Positive Effect

Titanium honeycomb sandwich structures are gradually used in newly developed aircrafts in China. In this study, low-velocity impact tests on the titanium honeycomb sandwich structures were carried out to obtain the impact dynamic response and investigate the typical impact damage modes and parameters including the depths and diameters of the facesheet indentation and the core crushing region. The test results showed that the maximum contact force, the diameter and depth of the indentation had strong positive correlations to the impact energy. Numerical analysis was also conducted to study the low-velocity impact behaviour of the titanium honeycomb sandwich structures by using parametric finite element models that contained all the geometric and the structural details of the titanium honeycomb cores. The numerical results successfully captured the typical low-velocity impact damage modes of the titanium sandwich structures, similar to those observed in the tests. The predicted impact dynamic response also agreed very well with the test data. By using the validated finite element models, a parameter sensitivity study on the effects of the structural parameters on the low-velocity impact damage behaviour of the titanium sandwich structures was conducted. The parametric analysis results showed that the impactor diameter, the facesheet thickness and the core cell wall thickness had positive effect on the maximum contact force, and negative effect on the indentation depth, while the height of the honeycomb core had positive effect on the contact force, but little influence on the indentation depth.

Time Dependent Low Velocity Impact Response of Turbomachinery Blade Made of Porous Exponential FGM

2019 ◽  
Author(s):  
Apurba Das ◽  
Gopal Agarwal ◽  
Kazuaki Inaba ◽  
Amit Karmakar
Keyword(s):  
Contact Force ◽  
Conical Shell ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Integration Scheme ◽  
Low Velocity ◽  
Conical Shells ◽  
Velocity Impact ◽  
Multiple Impact ◽  
The Impact

Abstract This study presents transient dynamic response of porous and non-porous exponential functionally graded (E-FGM) conical shells subjected to low velocity single and multiple impact. Hertzian contact law in modified form considering permanent indentation is used to calculate the impact response parameters. For finite element formulation eight-noded isoparametric shell element having five degrees of freedom per node is used. The dynamic equations for the low velocity impact problems are solved by Newmark’s time integration scheme. Parametric studies in terms of contact force, initial velocity of impactor, impactor displacement and shell displacement for Stainless Steel-Silicon Nitrite porous and non-porous conical shells (idealized as rotating turbo-machinery blade) under low velocity single and multiple impact are analyzed. Twist angle has significant effect on contact force but has marginal effect on contact duration. Contact force for perfect (porosity free) case is higher than that of porous one and the contact forces are found to decrease with higher porosity factor. Even porous FG conical shell is predicting lower contact force and higher shell displacement than that of uneven porous FG conical shell for a given porosity factor.

scholarly journals Low Velocity Impact Response and Tensile Strength of Epoxy Composites with Different Reinforcing Materials

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3059 ◽  
Author(s):  
Sebastian Sławski ◽  
Małgorzata Szymiczek ◽  
Jarosław Kaczmarczyk ◽  
Jarosław Domin ◽  
Eugeniusz Świtoński
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Optical Microscope ◽  
Impact Response ◽  
Epoxy Composites ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Reinforcing Material ◽  
The Impact

This paper presents the results of research concerning multilayered epoxy composites reinforced with different materials. The strength of multilayered composites depends, to a large extent, on the reinforcing material. The authors decided to compare the low velocity impact response and perform tensile strength tests on several composites, to ascertain the mechanical properties of the prepared composites. Five different reinforcing materials were provided for the research (two fabrics made from aramid fibers, two fabrics made from carbon fibers and one fabric made from polyethylene fibers). The composites were manufactured by the vacuum supported hand laminating method. The low velocity impact response tests were conducted with the use of a pneumatic launcher. Three strikers with different geometry (conical striker, hemispherical striker and ogival striker) were used. A comparison of the resulting damage to the composites after the impact of the strikers was based on the images obtained using an optical microscope; tensile tests were also performed. The experimental investigation showed significant differences in the mechanical properties of the composites, depending on the applied reinforcing material. It was found that, as a result of the impacts, less damage occurred in the composites which were characterized by a lower Young’s modulus and a higher tensile strength.

Low-velocity impact behavior of incorporated GFRP composites with nanoclay and nanosilica in a corrosive environment: Experimental and numerical study

2021 ◽  
pp. 002199832110316
Author(s):  
Yasaman Gitiara ◽  
Reza Barbaz-Isfahani ◽  
Saeed Saber-Samandari ◽  
Mojtaba Sadighi
Keyword(s):  
Numerical Study ◽  
Specific Effect ◽  
Low Velocity Impact ◽  
Impact Behavior ◽  
Corrosive Environment ◽  
Low Velocity ◽  
Impact Properties ◽  
Velocity Impact ◽  
Force Time ◽  
The Impact

Investigation and analysis of the dynamic behavior of composite materials and their failure resistance are essential. The main aim of this study is to investigate the improvement of impact properties of incorporated glass fiber reinforced polymer (GFRP) composite specimens with various loading of nanoclay and nanosilica in a corrosive environment. After fabrication of samples by hand layup method, all of them were immersed in 5 wt. % of sulfuric acid solution for 0, 1 and 3 months. As the immersion time increased, the specimens containing nanosilica absorbed more water than the other samples. The force-displacement, force-time and energy-time diagrams showed the superiority of filled composites with nanoparticles over the pure sample in all immersion periods. Low-velocity impact (LVI) test results of specimens containing nanoclay showed a better behavior and with the addition of 5 wt. % of nanoclay, the impact force increased by 15.72% and the displacement decreased by 5.26%. Also, in these samples, the energy absorption rate decreased by 17.15%, which was associated with a reduction in the damage rate. After immersion of specimens in different times, specimens containing 5 wt. % of nanoclay had better strength than other samples and maintained their superior properties. The obtained results illustrated that the addition of 1 and 3 wt. % of nanosilica had no specific effect on the improvement of impact properties. Finally, incorporated GPRP composites with 3 wt. % of nanoparticles were simulated using LS-DYNA software and the experimental and numerical results were compared to investigate their accordance.

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.

Sign in / Sign up

Export Citation Format

Share Document