scholarly journals Improving the Shock Resistance of Agricultural Composite Units Using Visco-Elastic Fluids

2020 ◽  
Vol 30 (2) ◽  
pp. 268-286
Author(s):  
Mikhail V. Astakhov ◽  
Ekaterina V. Slavkina
Keyword(s):  
Mechanical Characteristics ◽  
Layer Structure ◽  
Impact Resistance ◽  
Statistical Processing ◽  
Polymer Composite Material ◽  
Relative Deformation ◽  
Shock Loads ◽  
Additional Layer ◽  
Applied Forces ◽  
The Impact

Introduction. The use of composite materials in agricultural engineering is known as one of the recommended ways to reduce the weight of the structure and protect against corrosion. The main disadvantages of such products are their low resistance to shock loads that occur during operation. The aim of this study is to develop a glass composite multi-layer structure of the trailer side, capable of withstanding shock loads along with statically applied forces, without including additional reinforcing metal elements in the zones of the possible impacts. Materials and Methods. To increase the impact resistance of the product (after an analysis of modern design solutions) the use of visco-elastic non-Newtonian fluids based on polysilicon by introducing an additional layer into the power element to compensate for impact effects is proposed. Results. On the basis of laboratory testing using statistical processing of the obtained data, the basic mechanical characteristics of non-Newtonian fluid (polysilicon) during impact tests (density, Poisson’s ratio, Young’s modulus, shear modulus) are determined, and graphs of the obtained dependencies are constructed. The temperature of the tested polysilicon samples did not significantly affect their mechanical properties. It is established that starting from the value of relative deformation 0.042, during the impact polysilicon shows linearly elastic properties. Discussion and Conclusion. Based on the received mechanical characteristics, the conclusions about resistance to shock loads of polysilicon as a component of a trailer board element are made. The variant of arrangement of the trailer board structural solution as a multilayer sandwich element with external parts made of polymer composite material with internal filling with fiberglass cells and polysilicon placed in large cells is offered.

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.

An experimental and simulation study of impact resistance in sandwich structures casing

2018 ◽  
Vol 233 (10) ◽  
pp. 3635-3648
Author(s):  
Shuyi Yang ◽  
Cang Chen ◽  
Guiwen Liu
Keyword(s):  
Double Layer ◽  
Simulation Study ◽  
Sandwich Structure ◽  
Sandwich Structures ◽  
Layer Structure ◽  
Impact Resistance ◽  
Head Shape ◽  
Double Layer Structure ◽  
Single Structure ◽  
The Impact

As the main force component on the aeroengine, casing is one of bases of the whole aeroengine, but it is extremely difficult to analyze the capacity of aeroengine casing impact resistance. An experimental and simulation study of impact resistance has been conducted on sandwich structures casing with aluminum honeycombs to identify and improve aeroengine casing impact resistance. Firstly, a Rent–Ipson model has been applied to analyze the energy of broken blades with impacting casing. Based on a sensing test technology, the experimental research on the impact of aluminum honeycomb sandwich panel with a conical head shape bullet and a hemispherical head shape bullet have been carried out. The experimental results provide a basis for subsequent simulation research. Then the impact resistance have been compared and analyzed from single structure casing, double layer structure casing, and sandwich structure casing, according to their loss of blade kinetic energy, casing deformation, and the variation of casing internal energy. Finally, the variation of energy has been discussed during blade impacting casing with various oblique angles. Our results show that the impact resistance of sandwich structure casing is better than single structure casing and double layer structure casing. Most importantly, the impact resistance of casing has been improved with the increase of blade impact oblique angle.

A Smart Polymer Composite for Repeatedly Self-Healing Impact Damage in Fiber Reinforced Polymer (FRP) Vessels

2011 ◽  
Author(s):  
Jones Nji ◽  
Guoqiang Li
Keyword(s):  
Polymer Composite ◽  
Impact Damage ◽  
Glass Fibers ◽  
Shape Memory Polymer ◽  
Impact Resistance ◽  
Three Dimensional ◽  
Polymer Composite Material ◽  
Self Healing ◽  
Repeated Impact ◽  
The Impact

This paper investigated the impact properties of a novel polymer composite material with a potential to repeatedly self-heal impact damage in FRP vessels. The composite was fabricated by first dispersing copolyster thermoplastic particles in a shape memory polymer (SMP) matrix, and then reinforcing the material with three-dimensional (3D) woven glass fibers. Specimens of the reinforced composite with dimensions of 152 mm × 101 mm × 12.7 mm were produced by machining and divided into two groups (G1 and G2). G1 specimens were subjected to several impact/healing test cycles with 42 J of impact energy. G2 specimens were subjected to repeated impact test cycles with no healing at the same energy level. A third group of specimens without thermoplastic particles (G3), with identical dimensions as G2 was also produced and tested in a similar manner as G2 to evaluate the effects of thermoplastic particles on impact resistance. G2 specimens were perforated at the 40th impact while G3 specimens were perforated at the 27th impact. G1 specimens lasted an additional 9 rounds of impact to a total of 49 impacts compared to G2 specimens.

scholarly journals Study on the Mechanical Properties of Bionic Protection and Self-Recovery Structures

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 389
Author(s):  
Xue Guo ◽  
Xinju Dong ◽  
Zhenglei Yu ◽  
Zhihui Zhang ◽  
Xinyu Xie ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Energy Absorption ◽  
Double Layer ◽  
Layer Structure ◽  
Niti Alloy ◽  
Impact Resistance ◽  
Single Layer ◽  
Protective Structure ◽  
Bionic Structure ◽  
The Impact

A novel protective structure, based on shrimp chela structure and the shape of odontodactylus scyllarus, has been shown to improve impact resistance and energy absorption. A finite element model of NiTi alloy with shape memory was constructed based on the basic principles of structural bionics. The protective structure utilizes NiTi alloy as the matrix, a material with many advantages including excellent compression energy absorption, reusability after unloading, and long life. The mechanical properties of the single-layer model were obtained by static crushing experiments and numerical simulations. Building upon the idea of the monolayer bionic structure design, a two-layer structure is also conceived. Both single-layer and double-layer structures have excellent compression energy absorption and self-recovery capabilities. Compared with the single-layer structure, the double-layer structure showed larger compression deformation and exhibited better energy absorption capacity. These results have important academic and practical significance for improving the impact resistance of protective armor. Our study makes it possible to repair automatic rebounds under the action of pressure load and improves the endurance and material utilization rate of other protective structures.

The Applications of Direct Fluorinated HDPE in Oil & Gas Storage and Transportation

2011 ◽  
Vol 328-330 ◽  
pp. 2436-2439 ◽  
Author(s):  
Hong Wei Yang ◽  
Shi Liang Yang ◽  
Chao Wu ◽  
Yi Wei Fei ◽  
Xian Yong Wei
Keyword(s):  
Oil And Gas ◽  
Layer Structure ◽  
Impact Resistance ◽  
Single Layer ◽  
Gas Storage ◽  
Elemental Fluorine ◽  
Direct Fluorination ◽  
Fuel Tanks ◽  
The Impact ◽  
Oil Gas

Characteristics of elemental fluorine and carbon-fluorine bonds were analyzed. The barrier and oil-resistance properties of direct fluorination of HDOE were unveiled from molecule structure. The HDPE surface fluorination results in the increase of surface energy, cross link to some extent and shrinkage of polymer free volume.The application of direct fluorination of HDPE in oil in oil ＆ gas storage and transportation fields were reviewed, including oil and gas pipe,plastic petrol-tanks and HDPE impermeable membrane applied in oil tank foundation. After direct fluorination processing, the anti-corrosion and the permeability to hydrocarbons of HDPE pipes are strengthened. With the development of technology, it will be the trend that the multi-layer fuel tanks replace the single layer fuel tanks. The HDPE is applied as the outermost layer of multi-layer structure to ensure the processing property and the impact resistance in low temperature.

scholarly journals HYDROPHOBIZATION OF BASALT FIBER AND ITS INFLUENCE ON THE MECHANICAL CHARACTERISTICS OF SAND CONCRETE

2020 ◽  
pp. 114-120
Author(s):  
I.V. Barabash ◽  
◽  
A.I. Vorokhaiev ◽  
L.M. Ksonshkevуch ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Building Materials ◽  
Mechanical Characteristics ◽  
Impact Resistance ◽  
Basalt Fiber ◽  
Concrete Mixture ◽  
Test Machine ◽  
Sand Mixture ◽  
Polycarboxylate Superplasticizer ◽  
The Impact

Abstract. The materials of the proposed article are devoted to the study of mechanical properties of sand concrete with the addition of hydrophobized basalt fiber and polycarboxylate superplasticizer Relaxol-Super PC. Adding hydrophobic properties to the basalt fiber causes a decrease of water consumption of fine-grained concrete mixture, which leads to improved mechanical properties of concrete. The aim of the work was to increase the mechanical characteristics of sand concrete by introducing hydrophobized basalt fiber into its composition. The objective of the research is to study the effect of hydrophobized basalt fiber on the mechanical characteristics of sand concrete. The polycarboxylate superplasticizer Relaxol-Super PC (Budindustriya, Zaporozhye) was used to increase the mobility of the concrete mixture. Basalt fiber Bauson-basalt 12 mm long and 18 ± 2μm in diameter was used as a fibrous filler. Sand concrete mixture was prepared in a laboratory forced-action mixer. Dosing of Portland cement, quartz sand and basalt fiber was carried out by weight, water and water-reducing additive ‒ by volume, taking into account the density of the additive. The fiber was introduced into a dry cement-sand mixture. After mixing for 120 ... 150 seconds, water with a dosed amount of additive was introduced into the mixture. The hardening of samples concrete took place under normal conditions in a chamber with a temperature of 20 ± 20C and a relative humidity of at least 95%. The compressive strength of concrete was determined by testing the halves of the samples – beams 4×4×16 cm in size at 28 days of age. The abrasion of the investigated concrete was determined by testing cube specimens with an edge of 7.07 cm on an LKI-3 device in accordance with the procedure set forth in DSTU B.V.2.7-212: 2009 “Building materials. Concrete. Methods for determining abrasion “. The impact resistance of concrete was determined from the results of testing cubic specimens with an edge of 7.07 cm on a vertical dynamic laboratory test machine. Especially effective is manifested positive role hydrophobization basalt fiber in combination with the water-reducing additive Relaxol-Super PC. The introduction of hydrophobic fiber (2 kg/m3) and Relaxol – Super PC (1.2% by weight of cement) into the sand concrete mix provides an increase in the strength of sand concrete by 45 ... 48%, impact resistance by 45 ... 50%. The abrasion of concrete is reduced by 36 ... 48% compared to the control.

Effect of combined drink cans and steel fibers on the impact resistance and mechanical properties of concrete

2020 ◽  
Vol 14 (2) ◽  
pp. 6734-6742
Author(s):  
A. Syamsir ◽  
S. M. Mubin ◽  
N. M. Nor ◽  
V. Anggraini ◽  
S. Nagappan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Impact Resistance ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Indirect Tensile ◽  
The Impact

This study investigated the combine effect of 0.2 % drink cans and steel fibers with volume fractions of 0%, 0.5%, 1%, 1.5%, 2%, 2.5% and 3% to the mechanical properties and impact resistance of concrete. Hooked-end steel fiber with 30 mm and 0.75 mm length and diameter, respectively was selected for this study.  The drinks cans fiber were twisted manually in order to increase friction between fiber and concrete. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the strength performance of concrete, especially the compressive strength, flexural strength and indirect tensile strength. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the compressive strength, flexural strength and indirect tensile strength by 2.3, 7, and 2 times as compare to batch 1, respectively. Moreover, the impact resistance of fiber reinforced concrete has increase by 7 times as compared to non-fiber concretes. Moreover, the impact resistance of fiber reinforced concrete consistently gave better results as compared to non-fiber concretes. The fiber reinforced concrete turned more ductile as the dosage of fibers was increased and ductility started to decrease slightly after optimum fiber dosage was reached. It was found that concrete with combination of 2% steel and 0.2% drink cans fibers showed the highest compressive, split tensile, flexural as well as impact strength.    

scholarly journals Effect of SWCNT-Tuball Paper on the Lightning Strike Protection of CFRPs and Their Selected Mechanical Properties

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3140
Author(s):  
Kamil Dydek ◽  
Anna Boczkowska ◽  
Rafał Kozera ◽  
Paweł Durałek ◽  
Łukasz Sarniak ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Copper Foil ◽  
Impact Resistance ◽  
Mechanical Analysis ◽  
Lightning Strike ◽  
Single Wall Carbon Nanotubes ◽  
Carbon Fibre Reinforced Polymer ◽  
The Impact

The main aim of this work was the investigation of the possibility of replacing the heavy metallic meshes applied onto the composite structure in airplanes for lightning strike protection with a thin film of Tuball single-wall carbon nanotubes in the form of ultra-light, conductive paper. The Tuball paper studied contained 75 wt% or 90 wt% of carbon nanotubes and was applied on the top of carbon fibre reinforced polymer before fabrication of flat panels. First, the electrical conductivity, impact resistance and thermo-mechanical properties of modified laminates were measured and compared with the reference values. Then, flat panels with selected Tuball paper, expanded copper foil and reference panels were fabricated for lightning strike tests. The effectiveness of lightning strike protection was evaluated by using the ultrasonic phased-array technique. It was found that the introduction of Tuball paper on the laminates surface improved both the surface and the volume electrical conductivity by 8800% and 300%, respectively. The impact resistance was tested in two directions, perpendicular and parallel to the carbon fibres, and the values increased by 9.8% and 44%, respectively. The dynamic thermo-mechanical analysis showed higher stiffness and a slight increase in glass transition temperature of the modified laminates. Ultrasonic investigation after lightning strike tests showed that the effectiveness of Tuball paper is comparable to expanded copper foil.

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.

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