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Investigating the Effects of Welding Processes on Tensile Stress and Strain Properties of Welded Mild Steel Plates Using Statistical Analysis
Oladebeye Dayo Hephzibah,
Adejuyigbe Samuel Babatope,
Olorunnishola Akim Abayomi Gideon
Issue:
Volume 4, Issue 3, September 2020
Pages:
43-47
Received:
26 June 2020
Accepted:
13 July 2020
Published:
28 July 2020
Abstract: As test samples, mild steel plates with thicknesses of 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, and 1.0 mm were made. After welding these test samples underwent Tensile Stress and strain tests with the Built Welding Robot and Manual Electric Arc Welding Machine. Both data collected from tensile stress and tensile stress were analyzed and the data produced from Electric Arc welding operations, the Robot welding operations and un-welded plates (control) were compared with one another. The analyses of the data obtained from the developed welding robot, manual electric arc welding and un-welded (control) mild steel plates of different thicknesses were carried out for tensile stress and strain. The descriptive statistics, ANOVA analysis, test of homogeneity of Variances and Post Hoc test (Least Significant Differences) were the statistical tools deployed using Statistical Package of Social Sciences (SPSS version 2016). The results showed that the robot welding sample produced gave the lowest tensile stress while the un-welded samples (CONTROL) gave the highest. The un-welded (CONTROL) samples gave the highest tensile strain values while the lowest was given by the developed robot welding samples. Finally, it was evident from the analyses results that the welding processes have significant impact on the tensile stress and strain properties of the welded mild steel plates and that good welding quality can be achieved more with the developed welding robot.
Abstract: As test samples, mild steel plates with thicknesses of 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, and 1.0 mm were made. After welding these test samples underwent Tensile Stress and strain tests with the Built Welding Robot and Manual Electric Arc Welding Machine. Both data collected from tensile stress and tensile stress were analyzed and the data pr...
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Effects of Rotating Shaft Misalignment on Bearing Life and Lubricant Failure
Anthony Simons,
Henry Otoo,
Solomon Nunoo,
Ernest Ababio,
Cyrus Addy
Issue:
Volume 4, Issue 3, September 2020
Pages:
48-53
Received:
22 April 2020
Accepted:
30 June 2020
Published:
18 August 2020
Abstract: This study looks at plant and machinery at West African Mills Company Limited (WAMCO), with the view to identify sections within the factories with high cost of maintenance and provide a solution to reduce operating costs. Records of breakdowns at various sections of the plant were analysed and the first stage milling section at WAMCO II was found to have the highest cost of maintenance. On average, the breakdown of each of the three SCS4 grinding mills is about 14 times in a year. Furthermore, 27 bearings and 1.625 buckets of grease are used on the grinding mills alone costing an average of €10,000.00 annually on their maintenance. Some experiments were performed to ascertain how the rotating shaft misalignment occurs and the consequent change in parameters such as temperature, viscosity, power, and vibration. Bearing temperature readings at various misaligned shaft positions gave some indication of the criticality and likelihood of machine breakdowns. It was observed from the correlation analysis that there exist a strong positive relationship between the number of bearings, bucket of grease and man-hours used during breakdown and repairs. It was recommended that modern devices for monitoring be acquired and proper condition monitoring of the plant made to minimize the plant breakdowns and save money. Also, proper selection of bearing type for the mills should be looked at.
Abstract: This study looks at plant and machinery at West African Mills Company Limited (WAMCO), with the view to identify sections within the factories with high cost of maintenance and provide a solution to reduce operating costs. Records of breakdowns at various sections of the plant were analysed and the first stage milling section at WAMCO II was found ...
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Influence of Loading Speed on Acoustic Emission During Destruction of a Composite by Von Mises Criterion
Sergii Filonenko,
Viacheslav Stadychenko
Issue:
Volume 4, Issue 3, September 2020
Pages:
54-59
Received:
12 March 2020
Accepted:
14 April 2020
Published:
31 August 2020
Abstract: In this study of the composite material’s destruction caused by transverse force with the use of von Mises criterion, the simulation outcomes of the composite material’s cells destruction process and generated AE signals with increasing the strain rate is considered. The time dependencies of the change in the number of remaining elements and the generated AE signals with increasing the strain rate are obtained. Simulation outcomes of the process of composite cells destruction by von Mises criterion and generated acoustic emission signals with increasing strain rate are presented. It was determined that with increasing strain rate of the composite, there is an increase of decline rate of the strain curve of the remaining cells in time and a decrease in time of the destruction process. It was found that with increasing strain rate of the composite, the amplitude of the generated acoustic emission signal increases while its duration decreases, along with gradual transformation of the acoustic emission signal into a triangular signal. It was determined that with increasing strain rate of the composite, the pattern of change in the maximum amplitude of the generated acoustic emission signals has a linear character of increase, and their duration – nonlinear character of decline.
Abstract: In this study of the composite material’s destruction caused by transverse force with the use of von Mises criterion, the simulation outcomes of the composite material’s cells destruction process and generated AE signals with increasing the strain rate is considered. The time dependencies of the change in the number of remaining elements and the ge...
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Thermo-Structural Analysis of Carbon Fibre-Ni Based Super Alloy Composite Employed in Gas Turbines
Issue:
Volume 4, Issue 3, September 2020
Pages:
60-65
Received:
2 August 2020
Accepted:
27 August 2020
Published:
7 September 2020
Abstract: A computational analysis was carried out on two different materials of turbine blades, namely Inconel MA754 and Nimonic 80A, in order to determine their structural and thermal properties at elevated temperatures. Long carbon fibers of uniform length were used and deposited at varying thicknesses ranging from 1 mm to 4 mm, on the top surface of turbine blades and then analyzed for its performance. It is seen that the carbon fibers (IM10) embedded in the super alloys drastically improve the load bearing parameters of the configurations being analyzed. The improvement in structural load carrying ability is a result of higher Young's modulus primarily. Subsequent analysis with higher volume fraction of the fibers indicated saturation of performance at about 70% volume fraction for 4 mm fibers and significant improvement beyond it for the 1 mm fibers. With improvement in the load bearing characteristics the blade with fibers embedded into a tube like structure at 3 sections were configured and A thermal analysis of the same underscores the effectiveness of the 4 mm fibers in undergoing much reduced principal strains than other configurations. This is seen to be a result of insulation of the top surface from increase in temperature, which significantly reduces the thermal expansion, especially at the free end. This is in contrast to other configurations, where the low volume fraction of fibers resulted in high principal strain.
Abstract: A computational analysis was carried out on two different materials of turbine blades, namely Inconel MA754 and Nimonic 80A, in order to determine their structural and thermal properties at elevated temperatures. Long carbon fibers of uniform length were used and deposited at varying thicknesses ranging from 1 mm to 4 mm, on the top surface of turb...
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Effect of Inhibitor Concentration and Immersion Time on the Corrosion Rate and Inhibition Efficiency of AISI 1019 Steel in Inhibited Seawater Environment
Emmanuel Iyeni,
Cornelius Oghenetega Obemure
Issue:
Volume 4, Issue 3, September 2020
Pages:
66-80
Received:
19 January 2020
Accepted:
17 September 2020
Published:
25 September 2020
Abstract: The effect of inhibitor concentration and immersion time on the corrosion rate and inhibition efficiency of AISI 1019 steel in seawater environment were investigated by means of weight loss measurement (WLM) at an interval of 6days for a period of 60 days. AISI 1019 steel were immersed in seawater solution in the absence and presence of varying inhibitor concentrations of potassium chromate (PC), Sodium Nitrite (SN), Methyl Orange (MO), Methyl Red (MR), Terminalia Catappa Leaves (TCL) Extract, Carica papaya Leaves (CPL) Extract. The results showed that there is an increase in inhibition efficiency with increase in inhibitor concentration and decrease in inhibition efficiency with increase in immersion time. The inorganic inhibitor (potassium chromate), inorganic inhibitor (Sodium Nitrite), the organic Inhibitor (Methyl Orange), the organic inhibitor (Methyl Red), the green inhibitor (Terminalia Catappa Leaves) and green inhibitor (Carica Papaya Leaves) produced their best inhibition efficiency of 71.94%, 634%, 68.94%, 68.32%, 62.7%, 59.79% respectively at a concentration of 10g/L. From the result obtained, the potassium chromate inhibitor has better inhibitory property than other inhibitors, which revealed that it is best suited for inhibition of corrosion of mild steel in seawater environment.
Abstract: The effect of inhibitor concentration and immersion time on the corrosion rate and inhibition efficiency of AISI 1019 steel in seawater environment were investigated by means of weight loss measurement (WLM) at an interval of 6days for a period of 60 days. AISI 1019 steel were immersed in seawater solution in the absence and presence of varying inh...
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