Effect of Temperature and Moisture on the Impact Behavior of Graphite/Epoxy Composites: Part I—Impact Energy Absorption

1995 ◽  
Vol 17 (1) ◽  
pp. 3 ◽  
Author(s):  
WS Johnson ◽  
JE Masters ◽  
ML Karasek ◽  
LH Strait ◽  
MF Amateau ◽  
...  
Keyword(s):  
Energy Absorption ◽  
Impact Energy ◽  
Epoxy Composites ◽  
Impact Behavior ◽  
Effect Of Temperature ◽  
The Impact

Effect of Temperature and Moisture on the Impact Behavior of Graphite/Epoxy Composites: Part II—Impact Damage

1995 ◽  
Vol 17 (1) ◽  
pp. 11 ◽  
Author(s):  
WS Johnson ◽  
JE Masters ◽  
ML Karasek ◽  
LH Strait ◽  
MF Amateau ◽  
...  
Keyword(s):  
Impact Damage ◽  
Epoxy Composites ◽  
Impact Behavior ◽  
Effect Of Temperature ◽  
The Impact

Effect of Temperature on Impact Properties of ZA27 Alloy

2012 ◽  
Vol 476-478 ◽  
pp. 75-80 ◽  
Author(s):  
Li Ping Zhong ◽  
Jia Yong Si ◽  
Zi Qiao Zheng
Keyword(s):  
Impact Toughness ◽  
Fracture Surface ◽  
Impact Energy ◽  
Impact Testing ◽  
Impact Fracture ◽  
Impact Behavior ◽  
Effect Of Temperature ◽  
Za27 Alloy ◽  
Different Temperatures ◽  
The Impact

The impact toughness of ZA27 alloy at different temperatures is investigated by pendulum impact testing. In addition, the morphology of impact fracture surface observed by SEM. The results indicate that impact energy of ZA27 alloy is reduced with the temperature rising when the temperature is lower than 100°C. At 100°C to 200°C, impact energy increase as the temperature rising. And when the temperature reaches to 250°C, impact energy suddenly descend. Impact energy is the highest and reaches to 72.768J at 20°C. At impact fracture surface, it is mostly tear ridges and dimples. The higher the impact energy is, the more obvious the characteristic of tear ridges is. Furthermore, dimples are small and distribute more uniformly. Lower the impact energy, the less distinct of tear ridges. Dimples are larger and deeper, their distribution are not uniform. Impact behavior of material could be evaluated by the width of impact curve. The wider the peak of impact curve, the higher the impact toughness. But impact toughness is worse while peak is narrow.

Sandwiched hollow sphere structures: A study of ballistic impact behavior using numerical simulation

2013 ◽  
Vol 228 (12) ◽  
pp. 2068-2078 ◽  
Author(s):  
Yibin Fu ◽  
Jun Zhou ◽  
Xiaosheng Gao
Keyword(s):  
Energy Absorption ◽  
Impact Energy ◽  
Hollow Sphere ◽  
Ballistic Impact ◽  
Impact Behavior ◽  
Sphere Diameter ◽  
Impact Area ◽  
Impact Protection ◽  
The Impact ◽  
Sandwich Core

Sandwiched hollow sphere structure may have the potential to provide better ballistic impact protection as compared with monolithic plate based on the same weight and impact area. In the previous study of a sandwiched hollow sphere structure by the authors, a novel unit cell was created as a basic building unit of the structure, the tumbling effect was observed for significant impact energy absorption, and the existence of an optimal yield stress or hardness was proved for maximizing the impact energy absorption. However, the impact energy absorption ability of the sandwiched hollow sphere structure may also relate to many other factors. In this study, the diameter relation between the incoming projectile and the spheres in the sandwich core, the projectile initial impact velocity, and the sphere arrangement in the sandwich core are examined. It is revealed that the first layer sphere diameter should be comparable to the diameter of the incoming projectile, the diameter of spheres in different layers in one sandwich core should either decrease or increase monotonically, and there exists a critical impacting speed, at which the sandwiched sphere structure is most effective for impact energy absorption, etc. All these findings make the sandwiched hollow sphere structure a promising new member to the passive armor family.

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 Effect of extreme cold temperatures on quasi-static indentation and impact behavior of woven carbon fiber epoxy composite sandwich panels with nomex honeycomb core

2021 ◽  
pp. 109963622199387
Author(s):  
Mathilde Jean-St-Laurent ◽  
Marie-Laure Dano ◽  
Marie-Josée Potvin
Keyword(s):  
Epoxy Composite ◽  
Impact Behavior ◽  
Effect Of Temperature ◽  
Cold Temperatures ◽  
Composite Sandwich Panels ◽  
Composite Sandwich ◽  
Static Indentation ◽  
Nomex Honeycomb ◽  
Extreme Cold ◽  
The Impact

The effect of extreme cold temperatures on the quasi-static indentation and the low velocity impact behavior of woven carbon/epoxy composite sandwich panels with Nomex honeycomb core was investigated. Impact tests were performed at room temperature, –70°C, and –150°C. Two sizes of hemispherical impactor were used combined to three different impactor masses. All the impact tests were performed at the same initial impact velocity. The effect of temperature on the impact behavior is investigated by studying the load history, load-displacement curves and transmitted energy as a function of time curves. Impact damage induced at various temperatures was studied using different non-destructive and destructive techniques. Globally, more damages are induced with impact temperature decreasing. The results also show that the effect of temperature on the impact behavior is function of the impactor size.

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.

Energy absorption from composite reinforced with high performance auxetic textile structure

2020 ◽  
pp. 002199832096455
Author(s):  
Fernanda Steffens ◽  
Fernando Ribeiro Oliveira ◽  
Raul Fangueiro
Keyword(s):  
Energy Absorption ◽  
High Performance ◽  
Poisson Ratio ◽  
Impact Behavior ◽  
Knitted Fabrics ◽  
Reinforced Composite ◽  
Composite Fabrication ◽  
Impact Experiment ◽  
Key Factor ◽  
The Impact

The objective of this study is to analyze the impact behavior on the basis of energy approach of weft knitted structures, namely a jersey composite and an auxetic composite using high performance yarns. Weft knitted fabrics were produced with the same structural and machine parameters, using 100% para-aramid and hybrid (47% para-aramid and 53% polyamide) structure. Composite fabrication was achieved through hand lay-up using epoxy resin. Negative Poisson ratio of the reinforcing auxetic fabric was transferred from the fabric to the composite developed. Results obtained by drop weight dart impact test show that the impact experiment with different impact loads confirmed the auxetic composites, regardless de material composition, have an increase in the total energy absorption compared to jersey reinforced composite, approximately 2.5 and 4 times more for para-aramid and hybrid composite, respectively. Auxetic composites developed within this work present great potential for applications in different areas, mainly where energy absorption is a key factor to be considered, such as in protection, sports among others.

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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