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.

scholarly journals The Influence of Shape Memory Alloy Volume Fraction on the Impact Behavior of Polymer Composites

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1280 ◽  
Author(s):  
Min Sun ◽  
Xiaokun Sun ◽  
Zhenqing Wang ◽  
Mengzhou Chang ◽  
Hao Li
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Polymer Composites ◽  
Volume Fraction ◽  
Low Velocity Impact ◽  
Impact Behavior ◽  
Low Velocity ◽  
Velocity Impact ◽  
Impact Performance ◽  
The Impact

The low-velocity impact behavior of Shape Memory Alloy (SMA) reinforced resin matrix polymers is investigated and the influence of the SMA volume fraction on the impact performance of polymer composites is considered for the first time, which are the highlights in this paper. Firstly, 12 kinds of polymer composite specimens with different SMA volume fractions are fabricated in terms of the SMA layup spacing, SMA diameter, and the interaction between the two. Secondly, a low-velocity impact test is carried out in order to study the impact performances of the above polymer composites. Finally, the damage morphology of the specimen after impact is observed by the visualization method and the low-velocity impact performance of the 12 kinds of polymer composites is analyzed on the basis of the force and energy history curve.

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).

Low-velocity impact properties and finite element analysis of syntactic foam reinforced by warp-knitted spacer fabric

2016 ◽  
Vol 87 (16) ◽  
pp. 1938-1952 ◽  
Author(s):  
Chao Zhi ◽  
Hairu Long ◽  
Fengxin Sun
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Syntactic Foam ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Element Analysis ◽  
Velocity Impact ◽  
Impact Performance ◽  
Spacer Fabric ◽  
The Impact

The aim of this research was to investigate the low-velocity impact properties of syntactic foam reinforced by warp-knitted spacer fabric (SF-WKSF). In order to discuss the effect of warp-knitted spacer fabric (WKSF) and hollow glass microballoon parameters on the impact performance of composites, eight different kinds of SF-WKSF samples were fabricated, including different WKSF surface layer structures, different spacer yarn diameters and inclination-angles, different microballoon types and contents. The low-velocity impact tests were carried out on an INSTRON 9250 HV drop-weight impact tester and the impact resistances of SF-WKSF were analyzed; it is indicated that most SF-WKSF specimens show higher peak impact force and major damage energy compared to neat syntactic foam. The results also demonstrate that the surface layer structure, inclination-angle of the spacer yarn and the volume fraction and type of microballoon have a significant influence on the low-impact performance of SF-WKSF. In addition, a finite element analysis finished with ANSYS/LS-DYNA and LS-PrePost was used to simulate the impact behaviors of SF-WKSF. The results of the finite element analysis are in agreement with the experimental results.

Impact Energy for the First Crack of Reinforced Concrete with Partial Replacements of Sand by Fine Crumb Rubber

2013 ◽  
Vol 701 ◽  
pp. 286-290 ◽  
Author(s):  
Mustafa Maher Al-Tayeb ◽  
B.H. Abu Bakar ◽  
Hanafi Ismail ◽  
Hazizan Md Akil
Keyword(s):  
Reinforced Concrete ◽  
Impact Energy ◽  
Impact Loading ◽  
Crumb Rubber ◽  
Low Velocity Impact ◽  
Moist Air ◽  
Low Velocity ◽  
Velocity Impact ◽  
The Impact

Effects of partial replacements of sand by waste fine crumb rubber on the performance of reinforced concrete under low velocity impact loading were investigated. Specimens were prepared for 5%, 10% and 20 % replacements by volume of sand. All specimens were cured in moist air for 90 days. For each case, six beams of 100 mm ×100 mm × 500mm were subjected to 5.15 kg hammer from 900mm height. The number of blows of the hammer required to induce the first visible crack of the beam were recorded. The results are presented in terms of impact energy required for the first crack. The fine crumb rubbers increased the impact energy for first crack.

scholarly journals Low Velocity Impact Assessment Of Flax And Kevlar-Flax Fibre Reinforced Polymer Laminates Using Experimental and Numerical Methods

2021 ◽  
Author(s):  
Benedict Lawrence Sy
Keyword(s):  
Impact Toughness ◽  
Composite Laminates ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Impact Performance ◽  
Fibre Reinforced Polymer ◽  
The Cross ◽  
The Impact ◽  
Polymer Laminates

Flax/epoxy composite laminates were tested under low velocity impact loading, using passive Infra-Red thermography to monitor the damage evolution during the impact event. Two configurations were tested: unidirectional ([08F]S) and cross-ply ([(0/90)4F]S). The unidirectional laminate exhibited poor and brittle impact response. Conversely, the cross-ply laminate showed better impact performance with its energy penetration threshold three times higher than the unidirectional. Its impact toughness was also 2.5 times higher. Additional tests were conducted to evaluate the effect of hybridization with Kevlar®49. Test results showed significant improvement on the impact performance of the unidirectional flax/epoxy laminate. Hybridization increased its energy penetration threshold three times and impact toughness five times. Conversely, it reduced the penetration threshold of the cross-ply flax/epoxy laminate by 10%; however, it more than doubled the impact toughness. The impact toughness the Kevlar-Flax/epoxy laminates were slightly higher than those of aluminum and CFRP’s, making them sustainable alternatives for impact applications.

scholarly journals Simulations and Tests of Composite Marine Structures Under Low-Velocity Impact

2021 ◽  
Vol 28 (1) ◽  
pp. 59-71
Author(s):  
Zhaoyi Zhu ◽  
Xiaowen Li ◽  
Qinglin Chen ◽  
Yingqiang Cai ◽  
Yunfeng Xiong
Keyword(s):  
Composite Laminates ◽  
Impact Force ◽  
Low Velocity Impact ◽  
Back Side ◽  
Low Velocity ◽  
Velocity Impact ◽  
Damage Area ◽  
Impact Performance ◽  
Composite Ship ◽  
The Impact

Abstract Due to their excellent performance, composite materials are increasingly used in the marine field. It is of great importance to study the low-velocity impact performance of composite laminates to ensure the operational safety of composite ship structures. Herein, low-velocity drop-weight impact tests were carried out on 12 types of GRP laminates with different layup forms. The impact-induced mechanical response characteristics of the GRP laminates were obtained. Based on the damage model and stiffness degradation criterion of the composite laminates, a low-velocity impact simulation model was proposed by writing a VUMAT subroutine and using the 3D Hashin failure criterion and the cohesive zone model. The fibre failure, matrix failure and interlaminar failure of the composite structures could be determined by this model. The predicted mechanical behaviours of the composite laminates with different layup forms were verified through comparisons with the impact test results, which revealed that the simulation model can well characterise the low-velocity impact process of the composite laminates. According to the damage morphologies of the impact and back sides, the influence of the different layup forms on the low-velocity impact damage of the GRP laminates was summarised. The layup form had great effects on the damage of the composite laminates. Especially, the outer 2‒3 layers play a major role in the damage of the impact and the back side. For the same impact energy, the damage areas are larger for the back side than for the impact side, and there is a corresponding layup form to minimise the damage area. Through analyses of the time response relationships of impact force, impactor displacement, rebound velocity and absorbed energy, a better layup form of GRP laminates was obtained. Among the 12 plates, the maximum impact force, absorbed energy and damage area of the plate P4 are the smallest, and it has better impact resistance than the others, and can be more in line with the requirements of composite ships. It is beneficial to study the low-velocity impact performance of composite ship structures.

Experimental Investigation Into the Effect of Impact Loading on the Response of Metallic Trapezoidal Corrugated Core Sandwich Panels

2018 ◽  
Author(s):  
Haifu Yang ◽  
Yuansheng Cheng ◽  
Pan Zhang ◽  
Jun Liu ◽  
Kai Chen
Keyword(s):  
Dynamic Response ◽  
Impact Energy ◽  
Impact Loading ◽  
Sandwich Panels ◽  
Low Velocity Impact ◽  
Front Face ◽  
Low Velocity ◽  
Velocity Impact ◽  
Impact Location ◽  
The Impact

Sandwich structures with corrugated cores have attracted a lot of interest from industrial and academic fields due to their superior crashworthiness. In this paper, the dynamic response of metallic trapezoidal corrugated core sandwich panels under low-velocity impact loading is studied by conducting drop hammer impact testing. The sandwich panels composed of two thin face skins and trapezoidal corrugated core, were designed and fabricated through folding and laser welding technology. Main attention of present study was placed at the influences of the impact energy, impactor diameter and impact location on the impact force, deformation mechanisms and the permanent deflections of the trapezoidal corrugated core sandwich panels. Results revealed that the impact energy has significant effects on the dynamic response of the sandwich panel, whereas the impact diameter has little effects on it. The deformation mode of the front face sheet differs sharply when the impact location is different. The middle unit cell of corrugated core is compressed to the “M” shape under different low-velocity impact loading.

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.

scholarly journals An analytical model for predicting permanent plastic deflection and strain distributions in aluminium-alloy plates under low velocity impact loading

2017 ◽  
Vol 232 (16) ◽  
pp. 2861-2872
Author(s):  
Jiangbo Bai ◽  
Junjiang Xiong ◽  
Ajit R Shenoi ◽  
Meng Liu
Keyword(s):  
Aluminium Alloy ◽  
Analytical Model ◽  
Impact Loading ◽  
Impact Load ◽  
Yield Criterion ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Proposed Model ◽  
The Impact

This paper proposes a new analytical model to predict plastic deformation and strain distributions in aluminium-alloy plates under low velocity impact loading. The low velocity impact load on the fully clamped circular plate was idealized as a quasi-static normal point force acting at the centre of plate. Based on apt geometrical approximation and assumptions, governing equations were established to predict the out-of-plane deflection and the radial tensile, radial and circumferential flexure strains in fully clamped conditions. From the deformation theory of plasticity, a new formula was derived to estimate the impact load by incorporating strain-energy approach, bilinear strain-hardening constitutive model and the one-dimensional Tresca yield criterion. Low velocity impact tests were performed to confirm the proposed model and good correlation was achieved between the predictions and actual experiments, demonstrating the practical and effective use of the proposed model.

Effect of surface geometry on low-velocity impact behavior of laminated aramid-reinforced polyester composite

2016 ◽  
Vol 50 (29) ◽  
pp. 4077-4091 ◽  
Author(s):  
Ali İmran Ayten ◽  
Bülent Ekici ◽  
Arif Nihat Güllüoǧlu
Keyword(s):  
Energy Absorption ◽  
Volume Fraction ◽  
Low Velocity Impact ◽  
Surface Geometry ◽  
Low Velocity ◽  
Velocity Impact ◽  
Impact Tests ◽  
Polyester Composite ◽  
The Impact ◽  
Effect Of Surface

The aim of this study is to investigate the effect of surface geometry for low-velocity impact applications. To achieve this purpose, aramid fiber-reinforced laminated polyester composite with various geometries such as cylindrical, elliptical, and spherical were prepared, and low-velocity impact properties were investigated numerically and experimentally. All properties such as orientation, fiber volume fraction, matrix material, and average thickness are the same in all samples. Experimental low-velocity impact behaviors of structure were determined by drop weight tester at low velocity 2.012 m/s. Simulations were carried out by LS-Prepost 4.2 and LS-Dyna v971 software. By this way, results of impact tests were verified and modeled with finite element method. Results of the impact tests showed that the elliptical samples have the highest energy absorption capability due to effective stress transfer capacity. According to experimental results, maximum energy absorption rate difference is 17% between elliptical 10 mm and cylindrical 5 mm geometries.

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