Effect of adhesive interlayers on protective performance of bio-inspired building ceramic covering

2020 ◽  
Vol 23 (16) ◽  
pp. 3446-3455
Author(s):  
Yuyan Sun ◽  
Sheng Wang ◽  
Ziguo Wang
Keyword(s):  
Penetration Depth ◽  
Low Cost ◽  
Impact Resistance ◽  
Epoxy Adhesive ◽  
Building Ceramic ◽  
Ballistic Performance ◽  
Silicone Sealant ◽  
Brick And Mortar ◽  
Maximum Penetration ◽  
The Impact

The brick-and-mortar microstructure of nacre is usually considered as a source of inspiration for the development of strong and tough artificial materials. In this article, a nacre-inspired layered-and-staggered structural building ceramic protective covering was fabricated, and the effect of four types of adhesive materials on the ballistic performance of the protective covering was investigated through the ballistic test. The experimental results showed that under the impact of the 7.62-mm ordinary rifle bullet at a speed of 790–820 m/s, the average crater diameter in the concrete targets with protective covering was reduced by 40%–72%, and the penetration depth in the concrete was reduced by 70%–100%, compared with those of unprotected concrete targets. For the concrete targets with protective covering, that adopting the silicone sealant interlayers exhibited a smaller crater area but a maximum penetration depth, while that adopting the epoxy adhesive interlayers showed a larger crater area but a minimum penetration depth. Since the targets with the low-cost polyurethane sealant interlayers presented the smallest crater area and the shallower penetration depth, it can be concluded that the concrete with the protective covering using polyurethane sealant interlayers showed the better projectile impact resistance.

scholarly journals Towards Sustainable Concrete Composites through Waste Valorisation of Plastic Food Trays as Low-Cost Fibrous Materials

2021 ◽  
Vol 13 (4) ◽  
pp. 2073 ◽  
Author(s):  
Hossein Mohammadhosseini ◽  
Rayed Alyousef ◽  
Mahmood Md. Tahir
Keyword(s):  
Compressive Strength ◽  
Low Cost ◽  
Impact Resistance ◽  
Food Tray ◽  
World Population ◽  
Fibrous Materials ◽  
Palm Oil Fuel Ash ◽  
Waste Plastic ◽  
Compressive Strength Of Concrete ◽  
The Impact

Recycling of waste plastics is an essential phase towards cleaner production and circular economy. Plastics in different forms, which are non-biodegradable polymers, have become an indispensable ingredient of human life. The rapid growth of the world population has led to increased demand for commodity plastics such as food packaging. Therefore, to avert environment pollution with plastic wastes, sufficient management to recycle this waste is vital. In this study, experimental investigations and statistical analysis were conducted to assess the feasibility of polypropylene type of waste plastic food tray (WPFT) as fibrous materials on the mechanical and impact resistance of concrete composites. The WPFT fibres with a length of 20 mm were used at dosages of 0–1% in two groups of concrete with 100% ordinary Portland cement (OPC) and 30% palm oil fuel ash (POFA) as partial cement replacement. The results revealed that WPFT fibres had an adverse effect on the workability and compressive strength of concrete mixes. Despite a slight reduction in compressive strength of concrete mixtures, tensile and flexural strengths significantly enhanced up to 25% with the addition of WPFT fibres. The impact resistance and energy absorption values of concrete specimens reinforced with 1% WPFT fibres were found to be about 7.5 times higher than those of plain concrete mix. The utilisation of waste plastic food trays in the production of concrete makes it low-cost and aids in decreasing waste discarding harms. The development of new construction materials using WPFT is significant to the environment and construction industry.

scholarly journals The impact resistance of CTBN- modified epoxy adhesive joints

1994 ◽  
Vol 04 (C8) ◽  
pp. C8-771-C8-776 ◽  
Author(s):  
J. L. Lataillade ◽  
D. Grapotte ◽  
F. Cayssials
Keyword(s):  
Impact Resistance ◽  
Epoxy Adhesive ◽  
Adhesive Joints ◽  
The Impact ◽  
Modified Epoxy

Thermoplastique Degradation under Heat and Irradiation

2021 ◽  
Vol 904 ◽  
pp. 196-201
Author(s):  
Sonya Redjala ◽  
Said Azem ◽  
Nourredine Ait Hocine
Keyword(s):  
Mechanical Characteristics ◽  
Low Cost ◽  
Impact Resistance ◽  
Ultra Violet ◽  
Analytical Techniques ◽  
Mechanical Tests ◽  
Ultraviolet Rays ◽  
Technical Material ◽  
Effects Of Temperature ◽  
The Impact

The aim of the article is to highlight the effect of the environment on the properties of a polycarbonate (PC). It consists in aging this material under Ultra-violet (UV) combined with temperature for different periods of time, and to reveal the physicochemical and mechanical changes caused by aging. PC is a highly valued technical material for its various important characteristics and low cost. It finds its application in various fields but mainly in those whose requirements are the transparency and the impact resistance. The physicochemical and mechanicals characterizations of the marketed polycarbonate are necessary in order to highlight its intrinsic properties and to develop strategies that can improve its lifespan. In this work, we highlight the physicochemical and mechanical characteristics of virgin and aged polycarbonate. For this, analytical techniques and mechanical tests were used. A comparison of the characteristics revealed the combined effects of temperature and ultraviolet rays.

scholarly journals Preparation and Impact Resistance Properties of Hybrid Silicone-Ceramics Composites

2020 ◽  
Vol 10 (24) ◽  
pp. 9098
Author(s):  
Katarzyna Kośla ◽  
Paweł Kubiak ◽  
Marzena Fejdyś ◽  
Karolina Olszewska ◽  
Marcin Łandwijt ◽  
...  
Keyword(s):  
Impact Resistance ◽  
Young Modulus ◽  
Drop Tower ◽  
Body Armor ◽  
Soft Body ◽  
Ballistic Performance ◽  
Composite Armor ◽  
New Type ◽  
The Impact ◽  
Soft Body Armor

This article presents the method of preparation a new type of ballistic armor based on hybrid silicone-ceramic (HSC) composites with considerable flexibility. An experimental study on the ballistic behavior of HSC composites connected with soft body armor is presented against FSP.22 fragments. The effect of Al2O3 ceramics on the ballistic performance of HSC composite was investigated, and the fragmentation resistance process of the composite armor combining the HSC composite and soft aramid insert is clarified. Furthermore, impact resistance tests made with a drop tower which allows for a gravity drop of a mass along vertical guides onto a sample placed with an energy of 5 J were performed. The results presented in this paper show that the HSC composites can be successfully used as a hard body armor. However, they do not exhibit the properties of absorbing the impact energy generated during the drop tower tests. The test results show that the ballistic performance of composite armors is influenced by the hardness and Young modulus of ceramics and soft body armor panel. Additionally, in the article, the results of mechanical properties of silicones used for preparation of composites were presented and compiled to determine their role in the performance of impact protection.

Experimental and numerical study of the dynamic response of an adhesively bonded automotive structure

2020 ◽  
Vol 234 (14) ◽  
pp. 3385-3397
Author(s):  
NDD Silva ◽  
JJM Machado ◽  
EAS Marques ◽  
PMGP Moreira ◽  
LFM da Silva
Keyword(s):  
Adhesive Bonding ◽  
Numerical Study ◽  
Low Cost ◽  
High Strength ◽  
Epoxy Adhesive ◽  
Lap Joints ◽  
Impact Response ◽  
Vehicle Body ◽  
Component Level ◽  
The Impact

Based on economic and environmental factors related to energy efficiency, the automotive industry is being increasingly encouraged to design lighter structures, making use of adhesive bonding in vehicle body frames. To meet the standards of the automotive sector, adhesive joints must provide high strength and stiffness, low cost and good energy absorption at a component level, thereby ensuring good impact strength and passenger safety. This work aims to study, at room temperature (24°C), the impact response of a real scale automotive structure bonded with a crash-resistant epoxy, allowing to access the suitability of adhesives for automotive structural purposes. The epoxy adhesive was found to successfully transfer the loads to the aluminium substrates and not to compromise the integrity of the structure, as its failure was dominated by the behaviour of aluminium. Results obtained with a numerical model of the component were found to be in close agreement with the experimental failure load, demonstrating that numerical analysis can be a viable tool to predict the structure’s behaviour. In addition, a polyurethane was used as an alternative to the epoxy system to bond the structure, proving that the joint behaves better in the presence of a more flexible adhesive, as no failure was found for this case. Aluminium single-lap joints with two adhesive thicknesses were tested as a complement to understand the influence of this parameter on the impact response of a joint, showing a 21% decrease in strength when the highest thickness was used.

Ballistic Performance of Sandwich Composite Armor System

2020 ◽  
Author(s):  
Shah Alam ◽  
Samhith Shakar
Keyword(s):  
Impact Resistance ◽  
Absorption Capacity ◽  
Sandwich Composite ◽  
Skin Thickness ◽  
Ballistic Performance ◽  
Backing Plate ◽  
Composite Armor ◽  
Corrugated Structure ◽  
The Impact ◽  
Armor System

Abstract This study focused on the design, modelling and the analysis of the dynamic response of composite armor system, constructed with Kevlar 29 as front skin, Alumina-ceramic filled in x shaped corrugated structure as core and bottom skin Kevlar 29 and T800S, in terms of residual velocity, energy absorption capacity and limiting velocity. The core cell size, height, thickness, skin thickness, etc., will be varied to get their influence on the impact resistance. The design parameter will be investigated for the sandwich composite armor with various configurations and stacking sequence of Alumina Ceramics, Kevlar 29 and T800S. The sandwich typically consists of front plate, core and backing plate, which will be impacted at different velocities starting at 100m/s till significant armor penetration. The ballistic limit velocity (V50) will be determined from the analysis. The non-linear explicit dynamic analysis and simulation results computed using the software ABAQUS will be validated by experiment. From the data obtained it can be suggested which composite armor has improved impact resistance and performance.

Effect of austenitizing and tempering on impact resistance of a hot rolled high strength steel

2021 ◽  
Vol 21 (1) ◽  
pp. 15-19
Author(s):  
Haider Mahdi Lieth ◽  
Ali Sabea Hammood
Keyword(s):  
Mechanical Properties ◽  
High Strength Steel ◽  
Impact Resistance ◽  
High Strength ◽  
Metallographic Analysis ◽  
Ballistic Performance ◽  
Tempering Temperature ◽  
Quenching Medium ◽  
Hot Rolled ◽  
The Impact

The aim of this study is to investigate the effect of heat treatments on the impact properties of hot rolled high strength steel and describes the effect of tempering temperature and quenching media on the microstructure, hardness, and impact resistance of plates. In the present study a high strength steel was austenitized at 900 °C with different quenching medium and followed by tempering at 300 °C, 500 °C. After thermal treatments, the values of Charpy impact resistance, hardness, and microscopic structure were evaluated from mechanical and metallographic analysis of metals respectively. The change of mechanical properties and microstructure of the metal with the existence of heat treatment with the ballistic performance of high-strength steel. Experimental results showed that tempering at 500 °C for 2 hours after water quenching medium it provides the best mechanical properties in conjunct on with an improved in microstructure.

scholarly journals Comparative Study on the Impact Wedge-Peel Performance of Epoxy-Based Structural Adhesives Modified with Different Toughening Agents

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1549
Author(s):  
Gyeong-Seok Chae ◽  
Hee-Woong Park ◽  
Jung-Hyun Lee ◽  
Seunghan Shin
Keyword(s):  
Shear Strength ◽  
Automotive Industry ◽  
Impact Resistance ◽  
High Energy ◽  
Epoxy Adhesive ◽  
Absorbed Energy ◽  
Structural Adhesives ◽  
Epoxy Adhesives ◽  
The Impact ◽  
Modified Epoxy

Epoxy adhesives are widely used in various industries because of their high heat and chemical resistance, high cohesion, and minimal shrinkage. Recently, epoxy adhesives have been applied in the automotive industry as structural adhesives for lightweight vehicles. However, the brittleness of the epoxy is an obstacle for this application, since the automotive industry requires epoxy-based structural adhesives to have a high level of high-speed impact resistance. Hence, we used phenol-terminated polyurethane (PTPU) as a toughening agent for epoxy adhesives and compared the results with those that were obtained with carboxyl-terminated butadiene acrylonitrile copolymer (CTBN). The high-energy impact resistance of the epoxy adhesives was measured by the impact wedge-peel (IWP) test, and the shear strength was measured by the single lap joint test. As a result, the 20 wt % PTPU-modified epoxy adhesive showed remarkably higher total absorbed energy (25.8 J) during the IWP test and shear strength (32.3 MPa) as compared with the control epoxy adhesive (4.1 J and 20.6 MPa, respectively). In particular, the total absorbed energy of the PTPU-modified epoxy adhesive was much larger than that of the CTBN-modified epoxy adhesive (5.8 J). When more than 10 wt % PTPU was added, the modified epoxy adhesives showed stable crack growth and effectively transferred external stress to the substrate. These results were explained by changes in the glass transition temperature, crosslinking density, and morphology due to the toughening agents.

Movie Rental Business: Blockbuster, Netflix, and Redbox

2017 ◽  
pp. 1-21 ◽  
Author(s):  
Sunil Chopra ◽  
Murali Veeraiyan
Keyword(s):  
Business Model ◽  
Business Models ◽  
Low Cost ◽  
Video On Demand ◽  
Mail Order ◽  
Vending Machines ◽  
Video Rental ◽  
Brick And Mortar ◽  
The Face ◽  
The Impact

Jim Keyes, CEO of Dallas-based Blockbuster Inc., was facing the biggest challenge of his career. In March 2010 Keyes was meeting with Hollywood studios in an effort to negotiate better terms for the $1 billion worth of merchandise Blockbuster had purchased the year before. In recent years, Blockbuster's share of the video rental market had been sharply decreasing in the face of competitors such as the low-cost, convenient Redbox vending machines and mail-order and video-on-demand service Netflix. While Blockbuster's market capitalization had dropped 47 percent to $62 million in 2009, Netflix's had shot up 55 percent to $3.9 billion that year. The only hope for Blockbuster, as Keyes saw it, was to shift its business model from primarily brick-and-mortar physical DVD rentals to increased digital and mail-order video delivery. In Keyes's favor, the studios were more than willing to provide him with that help. Hollywood wanted to see Blockbuster win the video-rental wars. Consumers still made frequent purchases of DVDs at its store—purchases which were much more profitable for studios than the rentals that remained Blockbuster's primary business. Blockbuster had made efforts at making its business model more nimble, but the results had been disappointing, and its debt continued to skyrocket. By the end of 2009, the company's debt had climbed to $856 million, its share of the $6.5 billion video rental business had fallen to 27 percent, and its revenues had tumbled 23 percent to $4.1 billion.The objective of this case is to discuss how different business models and supply chain structures impact the financials of the firms in the DVD rental business. In particular, the goal is to convey that the characteristics of the movie (recent/big hit or old/eclectic) affect whether it is best rented from a centralized or decentralized model. In addition, as streaming gains market share, the impact will be different for movie types and business models.

scholarly journals Effect of Wood Fiber Surface Treatment on the Properties of Recycled HDPE/Maple Fiber Composites

2021 ◽  
Vol 5 (7) ◽  
pp. 177
Author(s):  
Roberto C. Vázquez Fletes ◽  
Denis Rodrigue
Keyword(s):  
Surface Treatment ◽  
Low Cost ◽  
Flexural Modulus ◽  
Wood Fiber ◽  
Impact Resistance ◽  
Tensile Modulus ◽  
Fiber Surface ◽  
Treated Fiber ◽  
Fiber Surface Treatment ◽  
The Impact

This work reports on the production and characterization of recycled high density polyethylene (R-HDPE) composites reinforced with maple fibers. The composites were produced by a simple dry-blending technique followed by compression molding. Furthermore, a fiber surface treatment was performed using a coupling agent (maleated polyethylene, MAPE) in solution. FTIR, TGA/DTG, and density analyses were performed to confirm any changes in the functional groups on the fiber surface, which was confirmed by SEM-EDS. As expected, the composites based on treated fiber (TC) showed improved properties compared to composites based on untreated fiber (UC). In particular, MAPE was shown to substantially improve the polymer–fiber interface quality, thus leading to better mechanical properties in terms of tensile modulus (23%), flexural modulus (54%), tensile strength (26%), and flexural strength (46%) as compared to the neat matrix. The impact resistance also increased by up to 87% for TC as compared to UC. In addition, the maximum fiber content to produce good parts increased from 15 to 75 wt% when treated fiber was used. These composites can be seen as sustainable materials and possible alternatives for the development of low-cost building/construction/furniture applications.

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