Effect of Cooling Medium on Fracture Toughness of Rotomoulded Product

2016 ◽  
Vol 852 ◽  
pp. 85-90
Author(s):  
P.L. Ramkumar ◽  
D.M. Kulkarni ◽  
Vikas V. Chaudhari
Keyword(s):  
Fracture Toughness ◽  
Testing Machine ◽  
Compact Tension ◽  
Vital Role ◽  
Point Of View ◽  
Body Parts ◽  
Rotational Moulding ◽  
Agricultural Industry ◽  
Moulding Process ◽  
Cooling Medium

In day-to-day life, usage of plastics is numerous. It offers variety of benefits compared to other materials in various sectors like house hold applications, agricultural industry, and packaging, etc. There are numerous methods for processing plastics. These include: blow moulding, injection moulding, rotational moulding, transfer moulding and thermoforming. Rotational moulding is a competitive alternative to other plastic manufacturing process, since it offers designers an opportunity to achieve an economic production of stress free products. Many products made by rotational moulding process using linear low density polyethylene (LLDPE) are widely used in outdoor applications such as boats, over head tanks, and car body parts etc. In such applications, fracture properties are considered to be critical from the quality characterization point of view. Selection of appropriate cooling medium plays vital role to enhance the quality of rotomolded products. In this paper, an attempt has been made to investigate the effect of cooling medium on fracture toughness of the rotationally moulded products. Fracture tests are carried out on a compact tension (CT) test specimens prepared as per the ASTM D 6068 (2012). The tests are performed on a universal testing machine. R-curve method is used to determine the fracture toughness (JIC) of rotomoulded products. From the experimental results it is found that rapid cooling method favours better fracture toughness of rotomoulded products. Therefore, it is recommended to use faster cooling aids like water cooling in rotational moulding process to achieve highest fracture toughness.

scholarly journals Void Content and its Influence on the Fracture Behaviour of Long Fibre Reinforced Injection Molded Polypropylene

2004 ◽  
Vol 13 (6) ◽  
pp. 096369350401300
Author(s):  
Victor Iliev Rizov
Keyword(s):  
Fracture Toughness ◽  
Testing Machine ◽  
Compact Tension ◽  
Void Content ◽  
Linear Elastic ◽  
Static Testing ◽  
Glass Fibre Reinforced ◽  
Injection Molded ◽  
Elastic Fracture ◽  
Static Testing Machine

The influence of void content on the fracture performance of discontinuous long glass fibre reinforced injection molded polypropylene was studied. Compact tension specimens were machined from simple plate-tools and were loaded in a static testing machine in a laboratory environment. From the resulting load-displacement curves the fracture toughness was determined on the basis of the linear elastic fracture mechanics. It was found that higher void content causes a decrease in the fracture toughness.

scholarly journals A Review; Application of Mechanical Monster in Era of Agricultural Industry

2020 ◽  
pp. 86-93
Author(s):  
Akshay Anjikar ◽  
Dr. Vinay Chandra Jha
Keyword(s):  
Real Life ◽  
Vital Role ◽  
Point Of View ◽  
Small Scale ◽  
Good Growth ◽  
Economic Point ◽  
Agricultural Industry ◽  
Indian Agriculture ◽  
New Ideas ◽  
Small Scale Farmers

In the Indian economy, agriculture plays a vital role. Over the last few decades, Indian agriculture has recorded good growth. Implementing new ideas in this field is very important, although a lot of work has been done in this area. The multipurpose farming robot is a fundamental and major agricultural machine for full yield. The traditional method of weeding, sowing seeds and spraying pesticides is a laborious procedure. In India, many farmers still use bullocks, horses, and buffalo for agricultural operations. In contrast to other countries around the world, this will not fulfil the need for agricultural energy requirements. We assume that human and animal efforts can be replaced from an economic point of view by some advanced mechanism that will be ideal for small-scale farmers. We are therefore designing this prototype and assume that it will fulfil all requirements and problems in real life. India is a country focused on agriculture in which 70% of individuals rely on the results of farming. But if we observe that with population growth the farm is spread among the family and because of this, farmers in India kept only two acres of farm on average. Economically, farmers are still very poor because they are unable to afford tractors and other expensive machinery, so they use conventional farming methods. So, we are designing this machinery that will fulfil all this need and solve the problem of labor.

scholarly journals Sustaining Rice Production through Biofertilization with N2-Fixing Cyanobacteria

2021 ◽  
Vol 11 (10) ◽  
pp. 4628
Author(s):  
Macarena Iniesta-Pallarés ◽  
Consolación Álvarez ◽  
Francisco M. Gordillo-Cantón ◽  
Carmen Ramírez-Moncayo ◽  
Pilar Alves-Martínez ◽  
...  
Keyword(s):  
Agricultural Practices ◽  
Vital Role ◽  
Rice Production ◽  
Point Of View ◽  
Paddy Fields ◽  
Nitrogen Fertilizers ◽  
Trophic Chain ◽  
Agricultural Practice ◽  
Biotechnological Potential

Current agricultural productivity depends on an exogenous nutrient supply to crops. This is of special relevance in cereal production, a fundamental part of the trophic chain that plays a vital role in the human diet. However, our agricultural practices entail highly detrimental side-effects from an environmental point of view. Long-term nitrogen fertilization in croplands results in degradation of soil, water, and air quality, producing eutrophication and subsequently contributing to global warming. In accordance with this, there is a biotechnological interest in using nitrogen-fixing microorganisms to enhance crop growth without adding chemically synthesized nitrogen fertilizers. This is particularly beneficial in paddy fields, where about 60% of the synthetic fertilizer that has been applied is dissolved in the water and washed away. In these agricultural systems, N2-fixing cyanobacteria show a promising biotechnological potential as biofertilizers, improving soil fertility while reducing the environmental impact of the agricultural practice. In the current study, Andalusian paddy fields have been explored to isolate N2-fixing cyanobacteria. These endogenous microorganisms have been subsequently re-introduced in a field trial in order to enhance rice production. Our results provide valuable insights regarding the use of an alternative natural source of nitrogen for rice production.

scholarly journals Interfacial Fracture Toughness Comparison of Three Indirect Resin Composites to Dentin and Polyether Ether Ketone Polymer

2020 ◽  
Vol 14 (03) ◽  
pp. 456-461
Author(s):  
Rayhaneh Khalesi ◽  
Mahdi Abbasi ◽  
Zahra Shahidi ◽  
Masoumeh Hasani Tabatabaei ◽  
Zohreh Moradi
Keyword(s):  
Fracture Toughness ◽  
Bond Strength ◽  
Testing Machine ◽  
Composite Resins ◽  
High Wear Resistance ◽  
Luting Cements ◽  
Anterior Teeth ◽  
Polyether Ether Ketone ◽  
Ether Ketone

Abstract Objectives Advances in laboratory composites and their high wear resistance and fracture toughness have resulted in their growing popularity and increasing use for dental restorations. This study sought to assess the fracture toughness of three indirect composites bonded to dental substrate and polyether ether ketone (PEEK) polymer. Materials and Methods This in vitro study was conducted on two groups of dental and polymer substrates. Each substrate was bonded to three indirect composite resins. Sixty blocks (3 × 3 × 12 mm) were made of sound bovine anterior teeth and PEEK polymer. Sixty blocks (3 × 3 × 12 mm) were fabricated of CRIOS (Coltene, Germany), high impact polymer composite (HIPC; Bredent, Germany), and GRADIA (Indirect; GC, Japan) composite resins. Composites were bonded to dentin using Panavia F 2.0 (Kuraray, Japan). For bonding to PEEK, Combo.lign (Bredent) and Visio.Link (Bredent) luting cements were used. In all samples, a single-edge notch was created by a no. 11 surgical blade at the interface. The samples were subjected to 3,500 thermal cycles, and their fracture toughness was measured in a universal testing machine (Zwick/Roell, Germany) by application of four-point flexural load. Statistical Analysis Data were analyzed using one-way analysis of variance, Kruskal–Wallis. Results The fracture toughness of CRIOS–PEEK interface was significantly higher than HIPC–PEEK. The fracture toughness of GRADIA–PEEK was not significantly different from that of HIPC and CRIOS. The fracture toughness of GRADIA–dentin was significantly higher than HIPC–dentin. Conclusion Considering the limitations of this study, GRADIA has the highest bond strength to dentin, while CRIOS shows the highest bond strength to PEEK.

The Fracture Toughness of Hardened Tool Steels

1987 ◽  
Vol 109 (4) ◽  
pp. 314-318 ◽  
Author(s):  
D. F. Watt ◽  
Pamela Nadin ◽  
S. B. Biner
Keyword(s):  
Fracture Toughness ◽  
Crack Growth ◽  
Slow Crack Growth ◽  
Crack Opening ◽  
Compact Tension ◽  
Testing Procedure ◽  
Tool Steels ◽  
Opening Displacement ◽  
Tempering Temperature ◽  
Toughness Testing

This report details the development of a three-stage fracture toughness testing procedure used to study the effect of tempering temperature on toughness in 01 tool steel. Modified compact tension specimens were used in which the fatigue precracking stage in the ASTM E-399 Procedure was replaced by stable precracking, followed by a slow crack growth. The specimen geometry has been designed to provide a region where slow crack growth can be achieved in brittle materials. Three parameters, load, crack opening displacement, and time have been monitored during the testing procedure and a combination of heat tinting and a compliance equation have been used to identify the position of the crack front. Significant KIC results have been obtained using a modified ASTM fracture toughness equation. An inverse relationship between KIC and hardness has been measured.

scholarly journals An experimental method to determine the intralaminar fracture toughness of high-strength carbon-fibre reinforced composite aerostructures

2018 ◽  
Vol 122 (1255) ◽  
pp. 1352-1370 ◽  
Author(s):  
H. Liu ◽  
B.G. Falzon ◽  
G. Catalanotti ◽  
W. Tan
Keyword(s):  
Fracture Toughness ◽  
Tensile Strength ◽  
Crack Tip ◽  
Damage Mechanism ◽  
Calibration Method ◽  
Compact Tension ◽  
Tensile Fracture ◽  
High Tensile Strength ◽  
Physical Test ◽  
Area Method

ABSTRACTCarbon fibres with high tensile strength are being increasingly utilised in the manufacture of advanced composite aerostructures. A Modified Compact Tension (MCT) specimen is often deployed to measure the longitudinal intralaminar fracture toughness but a high tensile strength often leads to premature damage away from the crack tip. We present an approach whereby the MCT specimen is supported by external fixtures to prevent premature damage. In addition, we have developed a novel measurement technique, based on the fibre failure strain and C-scanning, to determine the crack length in the presence of surface sublaminate delamination which masks the crack tip location. A set of cross-ply specimens, with a ((90/0)s)4 layup, were manufactured from an IMS60/epoxy composite system Two different data reduction schemes, compliance calibration and the area method, are used to determine the fibre-dominated initiation and propagation intralaminar fracture toughness values. Propagation values of fracture toughness were measured at 774.9 ± 5.2% kJ/m2 and 768.5 ± 4.1% kJ/m2, when using the compliance calibration method and the area method, respectively. Scanning Electron Microscopy (SEM) is carried out on the fracture surface to obtain insight into the damage mechanism of high-tensile-strength fibre-reinforced unidirectional composites. The measured tensile fracture toughness value is used in a fully validated computational model to simulate the physical test.

Experimental Determining of Mechanical and Elastic Characteristics for the Material Used in the Manufacturing of Cardan Crosses

2014 ◽  
Vol 657 ◽  
pp. 427-431
Author(s):  
Eugen Avrigean ◽  
Valentin Stefan Oleksik ◽  
Adrian Marius Pascu
Keyword(s):  
Testing Machine ◽  
Point Of View ◽  
Elastic Characteristics

The paper presents in its first part the need for analysing the functioning of the cardan cross within the cardan transmission, both from the point of view of shape and from the point of view of the material. In the second part there are described the main elements for analysing the test samples, the employed testing machine, as well as the manner of processing the obtained information. The last part contains the conclusions resulted from this analysis..

Contriving and Assessment of Magnesium Alloy Composites Augmented with Boron Carbide VIA Liquid Metallurgy Route

2022 ◽  
Vol 1048 ◽  
pp. 3-8
Author(s):  
J. Allen Jeffrey ◽  
S. Suresh Kumar ◽  
V. Anusha Roseline ◽  
A. Lazar Mary ◽  
D. Santhosh
Keyword(s):  
Boron Carbide ◽  
Testing Machine ◽  
High Strength ◽  
Stir Casting ◽  
Vital Role ◽  
Magnesium Metal ◽  
Hardness Tester ◽  
Universal Testing ◽  
Modern Engineering

In modern engineering low-density composites plays a vital role of which magnesium alloys are very effective due to its high strength with better corrosion resistance and neat cast ability. In this work a micron sized Boron carbide ceramic (B4C) of about 100 microns is diffused as a reinforcement with AZ91 for preparing a magnesium metal matrix composite (MMMC) through stir casting route. A modified pit furnace setup is used for doing stir casting with varying volume fractions of 0％ and 3% of boron carbide for doing the composites. Furthermore mechanical and metallurgical properties like Tensile test is made through universal testing machine, Micro-hardness through Vickers hardness tester and Micro structure through Optical Microscopy is done for investigation.

scholarly journals Fracture Toughness of Hybrid Components with Selective Laser Melting 18Ni300 Steel Parts

2018 ◽  
Vol 8 (10) ◽  
pp. 1879 ◽  
Author(s):  
Luis Santos ◽  
Joel de Jesus ◽  
José Ferreira ◽  
José Costa ◽  
Carlos Capela
Keyword(s):  
Fracture Toughness ◽  
Selective Laser Melting ◽  
Compact Tension ◽  
Powder Materials ◽  
Layer By Layer ◽  
Laser Melting ◽  
Conventional Steel ◽  
Scan Rate ◽  
Aisi H13 ◽  
3D Printed

Selective Laser Melting (SLM) is currently one of the more advanced manufacturing and prototyping processes, allowing the 3D-printing of complex parts through the layer-by-layer deposition of powder materials melted by laser. This work concerns the study of the fracture toughness of maraging AISI 18Ni300 steel implants by SLM built over two different conventional steels, AISI H13 and AISI 420, ranging the scan rate between 200 mm/s and 400 mm/s. The SLM process creates an interface zone between the conventional steel and the laser melted implant in the final form of compact tension (CT) samples, where the hardness is higher than the 3D-printed material but lower than the conventional steel. Both fully 3D-printed series and 3D-printed implants series produced at 200 mm/s of scan rate showed higher fracture toughness than the other series built at 400 mm/s of scan rate due to a lower level of internal defects. An inexpressive variation of fracture toughness was observed between the implanted series with the same parameters. The crack growth path for all samples occurred in the limit of interface/3D-printed material zone and occurred between laser melted layers.

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