scholarly journals Effect of Flexible Interphase on Impact Response in Aramid/Epoxy Composites

1996 ◽  
Vol 5 (6) ◽  
pp. 096369359600500 ◽  
Author(s):  
Kazuo Kitagawa ◽  
Satoru Hayasaki ◽  
Nobuo Ikuta ◽  
Zen-ichiro Maekawa
Keyword(s):  
Epoxy Resin ◽  
Energy Absorption ◽  
Impact Energy ◽  
Sol Gel ◽  
Testing Temperature ◽  
The Other ◽  
Impact Response ◽  
Epoxy Composites ◽  
Gel Method ◽  
The Impact

The flexible interphase in aramid/epoxy composites was investigated to enhance the impact response which is an advantage of aramid composites. Two kinds of procedures were performed to make flexible interphase using a flexible epoxy resin; one was sized with conventional epoxy resin and glycol acrylate and the other was coated with the mixture and a hardening catalyst using sol-gel method. Both composites showed higher impact energy absorption than that of the non-treated composite. The energy absorption increased with testing temperature. This was due to Tg of the flexible interphase.

scholarly journals The Effect of a Starch Envelope on Fly Ash Particles on the Impact Properties of Filled Epoxy Composites

2003 ◽  
Vol 12 (2) ◽  
pp. 096369350301200
Author(s):  
Kishore ◽  
N. L. Ravikumar ◽  
D. Sunil
Keyword(s):  
Fly Ash ◽  
Maximum Load ◽  
The Other ◽  
Impact Response ◽  
Epoxy Composites ◽  
Epoxy System ◽  
Ductility Index ◽  
Behavioural Patterns ◽  
The Impact ◽  
Fracture Features

The impact behaviour of epoxy specimens containing 20% by volume of fly ash particles without (coded, FA20) and with surface enveloped by starch in dry (FAS20) and water-ingresses (FASM20) conditions is studied. The resulting behavioural patterns are documented and compared to the composites containing as received fly ash particles. The data on unreinforced (i.e. neat) epoxy system (designated, NE) are also included. Samples with starch covering for the fillers whether tested in dry or wet conditions (i.e. FAS20 & FASM20) showed greater absorption of energy and maximum load compared to the ones derived on composites having as received fillers tested in unexposed (dry) condition (FA20). Ductility Index, D.I. on the other hand, showed a reversal in trends; the energy absorbed was highest for NE and lowest FA20 samples. Scanning microscopic examination of the fracture features was undertaken to correlate the microstructure to impact response.

Effect of Graphene Platelets/Fiber on Plastics Nanocomposites under Low-Velocity Impact Response

2016 ◽  
Vol 852 ◽  
pp. 23-28
Author(s):  
S. Subha ◽  
Battu Sai Krishna ◽  
Dalbir Singh ◽  
R. Gokulnath
Keyword(s):  
Energy Absorption ◽  
Impact Energy ◽  
Laminate Plate ◽  
Absorption Capacity ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Energy Absorption Capacity ◽  
Velocity Impact ◽  
The Impact

In this study, an attempt has made to explore the low-velocity impact response of a Carbon/epoxy laminate (CFRP) and E-Glass/epoxy laminates (GFRP). The composite was reinforced with Graphene Nanoplatelets (GnPs) and impact energy absorption capacity was studied. The plain GFRP and plain CFRP were served as a baseline for comparison. These composite laminate plates were fabricated using hand layup technique. The tests were carried out on the laminate plate as per ASTM D5628 FD. Impact tests were performed using a specially designed vertical drop-weight testing machine with an impactor mass of 1.926 kg. The result shows that laminate plate reinforced with GnPs reinforcement enhances the impact energy absorption capacity of the composites almost 4.5 % in the case Carbon/epoxy laminate and 3.5 % in the case of and E-glass/epoxy laminate. The enhanced impact resistance could be attributed to increased interlaminar fracture toughness of the fibres.

scholarly journals Effect of Layer Thickness in Layered Aluminum Matrix Syntactic Foam

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4172 ◽  
Author(s):  
Chenhao Qian ◽  
Chen Liang ◽  
Ziyang He ◽  
Weixi Ji
Keyword(s):  
Energy Absorption ◽  
Impact Energy ◽  
Syntactic Foam ◽  
Aluminum Matrix ◽  
Peak Stress ◽  
Impact Response ◽  
Syntactic Foams ◽  
Layer Number ◽  
Failure Propagation ◽  
The Impact

This work experimentally investigates the effect of layered structure on the static and impact response of a new layered syntactic foam developed for impact energy absorption. The layered syntactic foam had the same density of 1.6 g/cm3 and the same components of 50% large spheres (L) and 50% small spheres (S) with different structures from two layers to five layers. The impact response and energy absorption were investigated by drop-weight impact tests. Under static loading, more layers led to higher yield stress and lower energy absorption. There were three types of progressive failures of layered syntactic form under impact loading. The failure propagation was examined and found to be dependent on the layer number and impact energy. Interestingly, layered syntactic foam absorbed more energy than both of its components in terms of ductility. The ductility of layered syntactic foam decreased with the increase in layer number. The peak stress of layered syntactic foam increased with the increase in layer number. Two-layered syntactic foam LS had the highest ductility under 60 J/g impact, as well as an energy absorption of 35 J/g, compared to other layered syntactic foams. Specifically, its component L had a ductility under 70 J/g and an energy absorption of 25 J/g, while component S had a ductility under 10 J/g and an energy absorption of 10 J/g.

scholarly journals The Effect of a Starch Envelope on Fly Ash Particles on the Impact Properties of Filled Epoxy Composites

2003 ◽  
Vol 12 (4) ◽  
pp. 096369350301200 ◽  
Author(s):  
Kishore ◽  
N. L. Ravikumar ◽  
D. Sunil
Keyword(s):  
Fly Ash ◽  
Maximum Load ◽  
The Other ◽  
Impact Response ◽  
Epoxy Composites ◽  
Epoxy System ◽  
Ductility Index ◽  
Behavioural Patterns ◽  
The Impact ◽  
Fracture Features

The impact behaviour of epoxy specimens containing 20% by volume of fly ash particles without (coded, FA20) and with surface enveloped by starch in dry (FAS20) and water-ingresses (FASM20) conditions is studied. The resulting behavioural patterns are documented and compared to the composites containing as received fly ash particles. The data on unreinforced (i.e. neat) epoxy system (designated, NE) are also included. Samples with starch covering for the fillers whether tested in dry or wet conditions (i.e. FAS20 & FASM20) showed greater absorption of energy and maximum load compared to the ones derived on composites having as received fillers tested in unexposed (dry) condition (FA20). Ductility Index, D.I. on the other hand, showed a reversal in trends; the energy absorbed was highest for NE and lowest FA20 samples. Scanning microscopic examination of the fracture features was undertaken to correlate the microstructure to impact response.

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.

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).

Interplay of fabric structure and shear thickening fluid impregnation in moderating the impact response of high-performance woven fabrics

2020 ◽  
Vol 54 (28) ◽  
pp. 4387-4395
Author(s):  
Sanchi Arora ◽  
Abhijit Majumdar ◽  
Bhupendra Singh Butola
Keyword(s):  
Beneficial Effect ◽  
Energy Absorption ◽  
Impact Energy ◽  
High Performance ◽  
Research Work ◽  
Impact Resistance ◽  
Woven Fabrics ◽  
Woven Fabric ◽  
Fabric Structure ◽  
The Impact

The beneficial effect of STF impregnation in enhancing the impact resistance of high-performance fabrics has been extensively reported in the literature. However, this research work reports that fabric structure has a decisive role in moderating the effectiveness of STF impregnation in terms of impact energy absorption. Plain woven fabrics having sett varying from 25 × 25 inch−1 to 55 × 55 inch−1 were impregnated with STF at two different padding pressures to obtain different add-ons. The impact energy absorption by STF impregnated loosely woven fabrics was found to be higher than that of their neat counterparts for both levels of add-on, while opposite trend was observed in case of tightly woven fabrics. Further, comparison of tightly woven plain, 2/2 twill, 3/1 twill and 2 × 2 matt fabrics revealed beneficial effect of STF impregnation, except for the plain woven fabric, establishing that there exists a fabric structure-STF impregnation interplay that tunes the impact resistance of woven fabrics.

Dynamic Energy Absorption Performances of Rain Forest Vehicle (RFV) under Frontal Impact

2014 ◽  
Vol 67 (3) ◽  
Author(s):  
M. S. Othman ◽  
Z. Ahmad
Keyword(s):  
Energy Absorption ◽  
Impact Energy ◽  
Impact Loading ◽  
Rain Forest ◽  
Experimental Testing ◽  
Rigid Wall ◽  
Crash Analysis ◽  
Frontal Impact ◽  
Frontal Section ◽  
The Impact

This paper treats the crash analysis and energy absorption response of Rain Forest Vehicle (RFV) subjected to frontal impact scenario namely impacting rigid wall and column. Dynamic computer simulation techniques validated by experimental testing are used to carry out a crash analysis of such vehicle. The study aims at quantifying the energy absorption capability of frontal section of RFV under impact loading, for variations in the load transfer paths and geometry of the crashworthy components. It is evident that the proposed design of the RFV frontal section are desirable as primary impact energy mitigation due to its ability to withstand and absorb impact loads effectively. Furthermore, it is found that the impact energy transmitted to the survival room may feasibly be minimized in these two impact events. The primary outcome of this study is design recommendation for enhancing the level of safety of the off-road vehicle where impact loading is expected.   

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