Design and Processing of Alumina Plate Composites for Ballistic Nacre Alumina Structures

MRS Advances ◽  
2018 ◽  
Vol 3 (18) ◽  
pp. 957-962 ◽  
Author(s):  
A. Haynes ◽  
L. Reinhardt ◽  
C. Lim
Keyword(s):  
Shock Loading ◽  
Composite Plates ◽  
Impact Behavior ◽  
Structural Stiffness ◽  
Projectile Velocity ◽  
Composite Matrix ◽  
Aspect Ratios ◽  
Base Ceramic ◽  
Brick And Mortar ◽  
The Impact

ABSTRACTNacre is a hierarchical multi-composite matrix consisting of mineral plate-like structures stacked up similar to brick and mortar. When impacted with a projectile this type of structure is expected to reduce the overall shock loading into the system as well as projectile velocity as a consequence of variations in structural stiffness between the composite plates and the organic interlayers. Bio-mimicked nacre derived from alumina as the base ceramic is also shown to have increased fracture toughness over an alumina monolith. One challenge to building the nacre alumina structure is the design and processing of the composite mineral plates which should be comprised of roughly 90-95% nano-filler and 5-10% organic binder. In order for these plates to accurately mimic the nacre mineral plates they must also emulate aspect ratios on the order of 1:10 to 1:20. This paper will discuss the design and processing of nacre-alumina plates for studies into the impact behavior of nacre composites.

Modelling of Impact Behavior of Concrete Subjected to Shock Loading

2013 ◽  
Vol 577-578 ◽  
pp. 645-648
Author(s):  
Yuan Xiang Sun ◽  
Lin Xu
Keyword(s):  
Shock Loading ◽  
Coupled Model ◽  
Impact Behavior ◽  
Complex Behavior ◽  
Test Results ◽  
Proposed Model ◽  
The Impact

This paper presents a coupled model of damage and plasticity to describe the complex behavior of concrete subjected to shock loading. Comparison with the test results shows that the proposed model can give consistent prediction of the impact behavior of concrete.

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.

Designing a CRM Framework for online & offline sports footwear retailers

2015 ◽  
Vol 3 (1) ◽  
Author(s):  
Rodrigo Cueva ◽  
Guillem Rufian ◽  
Maria Gabriela Valdes
Keyword(s):  
Environmental Changes ◽  
Customer Relationship ◽  
Business Strategies ◽  
Economic Sectors ◽  
Running Shoes ◽  
Brick And Mortar ◽  
Key Factor ◽  
On Line ◽  
The Impact

The use of Customer Relationship Managers to foster customers loyalty has become one of the most common business strategies in the past years.  However, CRM solutions do not fill the abundance of happily ever-after relationships that business needs, and each client’s perception is different in the buying process.  Therefore, the experience must be precise, in order to extend the loyalty period of a customer as much as possible. One of the economic sectors in which CRM’s have improved this experience is retailing, where the personalized attention to the customer is a key factor.  However, brick and mortar experiences are not enough to be aware in how environmental changes could affect the industry trends in the long term.  A base unified theoretical framework must be taken into consideration, in order to develop an adaptable model for constructing or implementing CRMs into companies. Thanks to this approximation, the information is complemented, and the outcome will increment the quality in any Marketing/Sales initiative. The goal of this article is to explore the different factors grouped by three main domains within the impact of service quality, from a consumer’s perspective, in both on-line and off-line retailing sector.  Secondly, we plan to go a step further and extract base guidelines about previous analysis for designing CRM’s solutions focused on the loyalty of the customers for a specific retailing sector and its product: Sports Running Shoes.

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 long-term moisture exposure on impact response of glass-reinforced vinylester

2021 ◽  
pp. 147509022199616
Author(s):  
Fatemeh Alizadeh ◽  
Navid Kharghani ◽  
Carlos Guedes Soares
Keyword(s):  
Water Uptake ◽  
Failure Modes ◽  
Sea Water ◽  
Composite Plates ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Water Type ◽  
Interfacial Damage ◽  
Impact Properties ◽  
The Impact

Glass/Vinylester composite laminates are comprehensively characterised to assess its impact response behaviour under moisture exposure in marine structures. An instrumented drop weight impact machine is utilised to determine the impact responses of dry and immersed specimens in normal, salted and sea water. The specimens, which had three different thicknesses, were subjected to water exposure for a very long period of over 20 months before tested in a low-velocity impact experiment. Water uptake was measured primarily to study the degradation profiles of GRP laminates after being permeated by water. Matrix dissolution and interfacial damage observed on the laminates after prolonged moisture exposure while the absorption behaviour was found typically non-Fickian. The weight of the composite plates firstly increased because of water diffusion up to month 15 and then decreased due to matrix degradation. The specimens with 3, 6 and 9 mm thickness exhibited maximum water absorption corresponding to 2.6%, 0.7% and 0.5% weight gain, respectively. In general, the results indicated that water uptake and impact properties were affected by thickness and less by water type. Impact properties of prolonged immersed specimens reduced remarkably, and intense failure modes detected almost in all cases. The least sensitive to impact damage were wet specimens with 9 mm thickness as they indicated similar maximum load and absorbed energy for different impact energies.

Influence of nozzle exit geometrical parameters on supersonic jet decay

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Prasanta Kumar Mohanta ◽  
B. T. N. Sridhar ◽  
R. K. Mishra
Keyword(s):  
Aspect Ratio ◽  
Nozzle Exit ◽  
Ambient Air ◽  
Schlieren Image ◽  
Geometrical Parameters ◽  
Image Study ◽  
Aspect Ratios ◽  
Core Length ◽  
Supersonic Core Length ◽  
The Impact

Abstract Experiments and simulations were carried on C-D nozzles with four different exit geometry aspect ratios to investigate the impact of supersonic decay characteristics. Rectangular and elliptical exit geometries were considered for the study with various aspect ratios. Numerical simulations and Schlieren image study were studied and found the agreeable logical physics of decay and spread characteristics. The supersonic core decay was found to be of different length for different exit geometry aspect ratio, though the throat to exit area ratio was kept constant to maintain the same exit Mach number. The impact of nozzle exit aspect ratio geometry was responsible to enhance the mixing of primary flow with ambient air, without requiring a secondary method to increase the mixing characteristics. The higher aspect ratio resulted in better mixing when compared to lower aspect ratio exit geometry, which led to reduction in supersonic core length. The behavior of core length reduction gives the identical signature for both under-expanded and over-expanded cases. The results revealed that higher aspect ratio of the exit geometry produced smaller supersonic core length. The aspect ratio of cross section in divergent section of the nozzle was maintained constant from throat to exit to reduce flow losses.

Effect of inorganic nanofillers on the impact behavior and fracture probability of industrial high-density polyethylene nanocomposite

2017 ◽  
Vol 52 (18) ◽  
pp. 2431-2442 ◽  
Author(s):  
Harun Sepet ◽  
Necmettin Tarakcioglu ◽  
RDK Misra
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Density Polyethylene ◽  
Fracture Probability ◽  
High Density ◽  
Impact Behavior ◽  
Inorganic Filler ◽  
Melt Mixing ◽  
The Impact ◽  
Scanning Electron

The main purpose of this work is to study how the morphology of nanofillers and dispersion and distribution level of inorganic nanofiller influence the impact behavior and fracture probability of inorganic filler filled industrial high-density polyethylene nanocomposites. For this study, nanoclay and nano-CaCO3 fillers–high-density polyethylene mixings (0, 1, 3, 5 wt.% high-density polyethylene) was prepared by melt-mixing method using a compounder system. The impact behavior was examined by charpy impact test, scanning electron microscopy, and probability theory and statistics. The level of the dispersion was characterized with scanning electron microscopy energy dispersive X-ray spectroscopy analysis. The results showed rather good dispersion of both of inorganic nanofiller, with a mixture of exfoliated and confined morphology. The results indicated that the impact strength of the industrial nanocomposite decreased with the increase of inorganic particulate content. The impact reliability of the industrial nanocomposites depends on the type of nanofillers and their dispersion and distribution in the matrix.

Modes of Wave Propagation and Dispersion Relations in Inclusion Reinforced Composite Plates

2010 ◽  
Author(s):  
Yu Cheng Liu ◽  
Jin Huang Huang
Keyword(s):  
Composite Plate ◽  
Elastic Moduli ◽  
Lamb Waves ◽  
Plate Thickness ◽  
Composite Plates ◽  
Dispersion Relations ◽  
Elastic Behavior ◽  
Effective Elastic Moduli ◽  
Aspect Ratios ◽  
Reinforced Composite

This paper mainly analyzes the wave dispersion relations and associated modal pattens in the inclusion-reinforced composite plates including the effect of inclusion shapes, inclusion contents, inclusion elastic constants, and plate thickness. The shape of inclusion is modeled as spheroid that enables the composite reinforcement geometrical configurations ranging from sphere to short and continuous fiber. Using the Mori-Tanaka mean-field theory, the effective elastic moduli which are able to elucidate the effect of inclusion’s shape, stiffness, and volume fraction on the composite’s anisotropic elastic behavior can be predicted explicitly. Then, the dispersion relations and the modal patterns of Lamb waves determined from the effective elastic moduli can be obtained by using the dynamic stiffness matrix method. Numerical simulations have been given for the various inclusion types and the resulting dispersions in various wave types on the composite plate. The types (symmetric or antisymmetric) of Lamb waves in an isotropic plate can be classified according to the wave motions about the midplane of the plate. For an orthotropic composite plate, it can also be classified as either symmetric or antisymmetric waves by analyzing the dispersion curves and inspecting the calculated modal patterns. It is also found that the inclusion contents, aspect ratios and plate thickness affect propagation velocities, higher-order mode cutoff frequencies, and modal patterns.

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