scholarly journals Development of Methods to Improve the Mechanical Performance of Coated Grid-Like Non-Crimp Fabrics for Construction Applications

2019 ◽  
Vol 27 (1(133)) ◽  
pp. 51-58 ◽  
Author(s):  
Lars Hahn ◽  
Steffen Rittner ◽  
Dominik Nuss ◽  
Moniruddoza Ashir ◽  
Chokri Cherif
Keyword(s):  
Tensile Strength ◽  
Mechanical Performance ◽  
Coating Process ◽  
Ultrasonic Vibrations ◽  
Coating Agent ◽  
Industry Standard ◽  
Machine Setting ◽  
The Impact ◽  
The Relationship ◽  
Setting Parameters

This paper presents investigations aiming to improve the impregnation of a coating agent and thus increase the mechanical performance of geogrids, especially grid-like non-crimp fabrics (NCF) consisting of carbon fiber heavy tows (CFHT). The squeezing process is industry standard, but the relationship between the machine setting parameters (squeezing pressure and hardness of squeeze roll surface) and the impact on the tensile strength of grid-like NCF is still unexplored. The setting parameters evaluated lead to an increase in tensile strength of up to 10% compared to grid-like NCF coated without the squeezing process. Additionally the first insights into the coating process supported by ultrasonic vibrations based on CFHT single yarns are provided. It is shown that the tensile strength of treated CFHT can be increased by up to 12%, in comparison to CFHT coated without ultrasonic vibrations.

scholarly journals Review of the relationship between aggregates geology and Los Angeles and micro-Deval tests

2021 ◽  
Vol 80 (3) ◽  
pp. 1963-1980
Author(s):  
Solomon Adomako ◽  
Christian John Engelsen ◽  
Rein Terje Thorstensen ◽  
Diego Maria Barbieri
Keyword(s):  
Los Angeles ◽  
Crystal Size ◽  
Grain Shape ◽  
Mechanical Performance ◽  
Pore Space ◽  
Construction Material ◽  
Engineering Properties ◽  
Coarse Grained ◽  
The Impact ◽  
The Relationship

AbstractRock aggregates constitute the enormous volume of inert construction material used around the globe. The petrologic description as igneous, sedimentary, and metamorphic types establishes the intrinsic formation pattern of the parent rock. The engineering properties of these rocks vary due to the differences in the transformation process (e.g. hydrothermal deposits) and weathering effect. The two most common mechanical tests used to investigate the performance of aggregates are the Los Angeles (LA) and micro-Deval (MD) tests. This study reviewed the geological parameters (including mineralogy, grain and crystal size, grain shape, and porosity) and the relationship to Los Angeles and micro-Deval tests. It was found that high content of primary minerals in rocks (e.g. quartz and feldspar) is a significant parameter for performance evaluation. Traces of secondary and accessory minerals also affect the performance of rocks, although in many cases it is based on the percentage. Furthermore, some studies showed that the effect of mineralogic composition on mechanical strength is not sufficient to draw final conclusions of mechanical performance; therefore, the impact of other textural characteristics should be considered. The disposition of grain size and crystal size (e.g. as result of lithification) showed that rocks composed of fine-grain textural composition of ≤ 1 mm enhanced fragmentation and wear resistance than medium and coarse grained (≥ 1 mm). The effect of grain shape was based on convex and concave shapes and flat and elongated apexes of tested samples. The equidimensional form descriptor of rocks somehow improved resistance to impact from LA than highly flat and elongated particles. Lastly, the distribution of pore space investigated by means of the saturation method mostly showed moderate (R = 0.50) to strong (R = 0.90) and positive correlations to LA and MD tests.

scholarly journals Synchronously Strengthen and Toughen Polypropylene Using Tartaric Acid-Modified Nano-CaCO3

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2493
Author(s):  
Junlong Yao ◽  
Hanchao Hu ◽  
Zhengguang Sun ◽  
Yucong Wang ◽  
Huabo Huang ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Impact Toughness ◽  
Tartaric Acid ◽  
High Performance ◽  
Mechanical Performance ◽  
Low Cost ◽  
Complexing Agent ◽  
Environmental Technology ◽  
The Impact ◽  
First Time

In order to overcome the challenge of synchronously strengthening and toughening polypropylene (PP) with a low-cost and environmental technology, CaCO3 (CC) nanoparticles are modified by tartaric acid (TA), a kind of food-grade complexing agent, and used as nanofillers for the first time. The evaluation of mechanical performance showed that, with 20 wt.% TA-modified CC (TAMCC), the impact toughness and tensile strength of TAMCC/PP were 120% and 14% more than those of neat PP, respectively. Even with 50 wt.% TAMCC, the impact toughness and tensile strength of TAMCC/PP were still superior to those of neat PP, which is attributable to the improved compatibility and dispersion of TAMCC in a PP matrix, and the better fluidity of TAMCC/PP nanocomposite. The strengthening and toughening mechanism of TAMCC for PP involves interfacial debonding between nanofillers and PP, and the decreased crystallinity of PP, but without the formation of β-PP. This article presents a new applicable method to modify CC inorganic fillers with a green modifier and promote their dispersion in PP. The obtained PP nanocomposite simultaneously achieved enhanced mechanical strength and impact toughness even with high content of nanofillers, highlighting bright perspective in high-performance, economical, and eco-friendly polymer-inorganic nanocomposites.

Microstructure and Properties of Aluminium Processed by Constrained Groove Pressing

2008 ◽  
Vol 584-586 ◽  
pp. 535-540 ◽  
Author(s):  
Jozef Zrník ◽  
Tomas Kovarik ◽  
Miroslav Cieslar
Keyword(s):  
Tensile Strength ◽  
Electron Back Scatter Diffraction ◽  
Substantial Impact ◽  
Transmission Electron ◽  
Purity Aluminium ◽  
Commercial Purity Aluminium ◽  
The Impact ◽  
The Relationship ◽  
Strength And Ductility ◽  
Strain Increase

In this study, the relationship between the structure and properties of commercial purity aluminium (AW-1199) was investigated by applying constrained groove pressing (CGP) method. The refinement of the coarse grain aluminium microstructure to submicrocrystalline size by large plastic strain at room temperature defined. The impact of various strains upon microstructure changes is investigated using transmission electron microscopy (TEM) and electron back scatter diffraction (EBSD). A mixture of subgrains produced by grains subdivision and polygonized subgrains formed locally due to dynamic recovery was found in the deformed aluminium. The tensile properties and resulting hardness are related to microstructural evolution induced by CGP. A substantial impact of straining upon the increasing in tensile strength was observed after the first pass. Further strain increase had an insignificant effect on tensile strength but was accompanied by ductility loss. The post deformation annealing effect was then explored with aim to increase the ductility. The results indicate that changes in strength and ductility may be related to formation of a bimodal structure.

scholarly journals Impact of PVC mixtures of the Electrical Conduit on the Physical Properties: تأثير خلطات البي في سي لصناعة القنوات الكهربائية على الخواص الفيزيائية

2020 ◽  
Vol 4 (2) ◽  
Author(s):  
AbdelHamid M.S. Esmail
Keyword(s):  
Tensile Strength ◽  
Physical Properties ◽  
Correlation Coefficients ◽  
Strong Relationship ◽  
Chemical Components ◽  
Random Samples ◽  
Long Time ◽  
The Impact ◽  
The Relationship ◽  
Soft Point

The use of PVC mixtures in the manufacturing of electrical conduit has been employed for a long time along with other materials. In this study, the impact of changing the ratio of the components of the PVC mixtures on the physical properties of the electrical conduit was investigated. The emphasis was placed on three properties: Density, Tensile Strength and Soft Point. The application of the electrical conduit controls the types of materials and their percentages. Physical properties of the PVC products are the most important factors that help to choose compared with other materials. These properties change with the change of the chemical components of the PVC mixture. The study discussed how to enhance and improve these properties by controlling the proportions of some substances in the PVC mixtures. This article aims to demonstrate the strong relationship between PVC polymer, calcium and stabilizers and the physical properties of the electrical conduit. The focus concentrated on three components in the mixture and three physical properties. Random samples were taken to calculate the average percentages of the components in the mixtures. Various tools and several statistical methods were used such as correlation coefficients and scatter charts to prove the relationship between the ratios of the materials and the respective properties. The correlation coefficients between the PVC polymer, stabilizers, calcium, and the density, tensile strength, vicat soft points were (0.92, 0.83, 0.82) respectively. Decreasing the PVC polymer by (17.1%) has caused an increase in the density of the conduit by (2%). Finally, the physical properties of PVC mixtures could be improved by changing component ratios to reach the optimized mixture for the specific application, taking into account other competitive issues such as the final price of the product, environmental impact, and other issues.

The Preparation and Property of Organic Solvent Lignin and PVC Composite Materials

2011 ◽  
Vol 236-238 ◽  
pp. 1195-1198 ◽  
Author(s):  
Qing Wei Ping ◽  
Jing Xiao ◽  
Jian Zhao
Keyword(s):  
Tensile Strength ◽  
Composite Material ◽  
Organic Solvent ◽  
Mechanical Performance ◽  
Fracture Morphology ◽  
Impact Fracture ◽  
Dispersed Phase ◽  
Bend Strength ◽  
The Impact ◽  
Scanning Electron

The organic solvent lignin in this paper was extracted from the scrap liquid of the reed ethanol pulping. The attained lignin was characterized by Scanning Electron Microscope（SEM）.On this basis，the lignin is blended with PVC and other auxiliaries, PVC/lignin composite material is prepared by pressure molding. The mechanical performance index of PVC/lignin composite material is detected and the impact fracture morphology of the PVC/lignin composite material is observed by SEM photograph. According to the research, it is indicted that the lignin and PVC has a certain degree of compatibility. The less dosage of lignin, the better compatibility lignin and PVC performances. With the increasing of dosage of lignin, the impact strength, tensile strength and bend strength of PVC/lignin composite material decrease. Compared with 5 phr PVC/lignin composite material, the dispersed phase diameter of the impact fracture morphology of 20 phr PVC/lignin composite material becomes bigger, and the uniformity of distribution becomes worse.

scholarly journals UTILIZATION OF DIFFERENT TYPES OF FIBRES CEMENTOUS MATERIALS AND SBR LATEX IN THE CONCRETE - A REVIEW

2021 ◽  
pp. 98-102
Author(s):  
B. Kanna Babu ◽  
Bimalendu Dash
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Building Materials ◽  
Mechanical Performance ◽  
Current Trend ◽  
Split Tensile Strength ◽  
Nylon Fibre ◽  
The Impact ◽  
Strength And Ductility

Concrete’s tensile strength is low compared to its compressive strength when subjected to normal stresses and impact loads, making it brittle. Continuous reinforcing improves the strength and ductility of concrete, but it requires careful placement and the availability of labour. In this work, the impact of several types of concrete fibre characteristics was studied. The concept of using fibres to alter the characteristics of building materials isn’t new. When concrete cracks and randomly oriented fibres start to operate together, they prevent crack development and extension while also increasing strength and ductility. The current trend is to develop more effective crack-resistant concrete, such as reinforced fibre concrete. The geometric size and modulus of fibres are the key factors of the mechanical performance of fibre reinforced concrete. According to the findings, adding fibres to concrete enhances compressive strength, flexural strength, split tensile strength, ductility, and impact strength. KEY WORDS: Nylon Fibre; Latex; Compressive Strength; Split Tensile Strength; Flexural Strength, Durability.

scholarly journals Mechanical and thermal performance of additively manufactured copper, silver and copper–silver alloys

2021 ◽  
pp. 146442072110409
Author(s):  
John Robinson ◽  
Arun Arjunan ◽  
Ahmad Baroutaji ◽  
Mark Stanford
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Thermal Performance ◽  
Mechanical Performance ◽  
Three Dimensional ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Powder Bed ◽  
Three Dimensional Printing ◽  
Industry Standard

On-demand additive manufacturing (three-dimensional printing) offers great potential for the development of functional materials for the next generation of energy-efficient devices. In particular, novel materials suitable for efficient dissipation of localised heat fluxes and non-uniform thermal loads with superior mechanical performance are critical for the accelerated development of future automotive, aerospace and renewable energy technologies. In this regard, this study reports the laser powder bed fusion processing of high purity (>99%) copper (Cu), silver (Ag) and novel copper–silver (CuAg) alloys ready for on-demand additive manufacturing. The processed materials were experimentally analysed for their relative density, mechanical and thermal performance using X-ray computed tomography, destructive tensile testing and laser flash apparatus, respectively. It was found that while Ag featured higher failure strains, Cu in comparison showed a 109%, 17% and 59% improvement in yield strength ([Formula: see text]), Young’s modulus ( E) and ultimate tensile strength, respectively. As such the [Formula: see text], E and ultimate tensile strength for laser powder bed fusion Cu is comparable to commercially available laser powder bed fusion Cu materials. CuAg alloys, however, significantly outperformed Ag, Cu and all commercial Cu materials when it came to mechanical performance offering significantly superior performance. The [Formula: see text], E and ultimate tensile strength for the novel CuAg composition were 105%, 33% and 94% higher in comparison to Cu. Although slightly different, the trend continued with a 106% and 91% rise for [Formula: see text] and ultimate tensile strength, respectively, for CuAg in comparison to industry-standard Cu. Unfortunately, E values for industry-standard Cu alloys were not available. When it came to thermal performance, laser powder bed fusion Ag was found to offer a 70% higher thermal diffusivity in comparison to Cu despite the variation in density and porosity. CuAg alloys however only showed a 0.8% variation in thermal performance despite a 10–30% increase in Ag. Overall, the study presents a new understanding regarding the three-dimensional printing and performance of Cu, Ag and CuAg alloys.

scholarly journals Impact of PVC mixtures of the Electrical Conduit on the Physical Properties

2021 ◽  
Vol 10 (1) ◽  
pp. 20-27
Author(s):  
Abdelhamid Esmail
Keyword(s):  
Tensile Strength ◽  
Physical Properties ◽  
Correlation Coefficients ◽  
Strong Relationship ◽  
Chemical Components ◽  
Random Samples ◽  
Long Time ◽  
The Impact ◽  
The Relationship ◽  
Soft Point

The use of PVC mixtures in the manufacturing of electrical conduit has been employed for a long time along with other materials. In this study, the impact of changing the ratio of the components of the PVC mixtures on the physical properties of the electrical conduit was investigated. The emphasis was placed on three properties: Density, Tensile Strength and Soft Point. The application of the electrical conduit controls the types of materials and their percentages. Physical properties of the PVC products are the most important factors that help to choose compared with other materials. These properties change with the change of the chemical components of the PVC mixture. The study discussed how to enhance and improve these properties by controlling the proportions of some substances in the PVC mixtures. This article aims to demonstrate the strong relationship between PVC polymer, calcium and stabilizers and the physical properties of the electrical conduit. The focus concentrated on three components in the mixture and three physical properties. Random samples were taken to calculate the average percentages of the components in the mixtures. Various tools and several statistical methods were used such as correlation coefficients and scatter charts to prove the relationship between the ratios of the materials and the respective properties. The correlation coefficients between the PVC polymer, stabilizers, calcium, and the density, tensile strength, vicat soft points were (0.92, 0.83, 0.82) respectively. Decreasing the PVC polymer by (17.1%) has caused an increase in the density of the conduit by (2%). Finally, the physical properties of PVC mixtures could be improved by changing component ratios to reach the optimized mixture for the specific application, taking into account other competitive issues such as the final price of the product, environmental impact, and other issues.

Buckling behavior of cold-formed C/Z-section purlins incorporating the effects of diaphragm and the screw location

2019 ◽  
Vol 23 (6) ◽  
pp. 1114-1128
Author(s):  
Na Yang ◽  
Fan Bai
Keyword(s):  
Mechanical Performance ◽  
Buckling Load ◽  
Biaxial Bending ◽  
Distortional Buckling ◽  
Limit States ◽  
Buckling Behavior ◽  
Proposed Model ◽  
Flexural Torsional Buckling ◽  
The Impact ◽  
The Relationship

This article presents a study on the impact of the screw location and the diaphragm effects on the buckling behavior of the simply supported C/Z-section purlins under wind uplift loadings. The diaphragm effects provided by the sheeting and the warping-torsional effect induced by load eccentricity are taken into account in the differential equations of the nonlinear twisting flexural-torsional model. The biaxial bending moments, bi-moments, as well as the flexural-torsional buckling load of the purlin can be numerically obtained with the proposed model. The global, local, and distortional buckling interaction behavior and the limit states capacities are formulated based on the modified Direct Strength Method. The effects of both the restraints provided by the sheeting and impact of the screw location on the mechanical performance of the purlins are evaluated with the proposed method. The relationship between the buckling load and rotational restraint stiffness is also provided. The proposed methodology will contribute to the assessment of buckling capacity of purlin-sheeting systems.

Effect of Processing Conditions on the Microstructure Development during Constrained Groove Pressing of Aluminium

2014 ◽  
Vol 783-786 ◽  
pp. 331-337 ◽  
Author(s):  
Jozef Zrník ◽  
Libor Kraus ◽  
Miroslav Cieslar ◽  
Peter Sláma
Keyword(s):  
Tensile Strength ◽  
Room Temperature ◽  
Dynamic Recovery ◽  
Processing Conditions ◽  
Structure And Properties ◽  
Transmission Electron ◽  
The Impact ◽  
The Relationship ◽  
Strength And Ductility ◽  
Strain Increase

In this study, the relationship between the structure and properties of commercial purityaluminium (AW-1199) was investigated by applying constrained groove pressing (CGP) method.The refinement of the coarse grain aluminium microstructure to submicrocrystalline size by largeplastic strain at room temperature defined. The impact of various strains upon microstructurechanges is investigated using transmission electron microscopy (TEM) and electron back scatterdiffraction (EBSD). A mixture of subgrains produced by grains subdivision and polygonizedsubgrains formed locally due to dynamic recovery was found in the deformed aluminium. Thetensile properties and resulting hardness are related to microstructural evolution induced by CGP. Asubstantial impact of straining upon the increasing in tensile strength was observed after the firstpass. Further strain increase had an insignificant effect on tensile strength but was accompanied byductility loss. The post deformation annealing effect was then explored with aim to increase theductility. The results indicate that changes in strength and ductility may be related to formation of abimodal structure.

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