Ali S Yasir | University of Kufa - Iraq (original) (raw)

Papers by Ali S Yasir

Open Engineering, Dec 31, 2022

Journal of Applied Mechanical Engineering, 2020

Open Engineering, 2023

The fatigue life of polymer materials like epoxy can be improved by using stiffeners such as carb... more The fatigue life of polymer materials like epoxy can be improved by using stiffeners such as carbon fiber and/or adding multiwall carbon nanotubes (MWCNTs). This article studies the effect of adding MWCNTs with different ratios (0.5, 1, and 2 wt%) to epoxy and composite (epoxy + 30% carbon fibers). The experimental results of the fatigue test with fully reversed bending stress (with R = −1) showed a maximum increase of 788% in fatigue life when adding 1 wt% MWCNTs to epoxy, while the maximum improvement ratio reaches 2,500% when adding 1 wt % MWCNTs to composite. The best results of fatigue life improvement were observed for samples with MWCNTs of 1 wt%. The material will be transferred from low cycle fatigue (less than 10 5 cycles) to high cycle fatigue (more than 10 5 cycles) by adding 1 wt% of MWCNTs. At the same time, the ratio of MWCNTs of more than 1 wt% (such as 2 wt%) will decrease the fatigue life due to the agglomeration of nanotubes inside the resin and reduce the positive effect of it. These agglomeration points work as a barrier to load transfer and stress concentration points. The numerical model was built to simulate the fatigue test and compare the results with the experimental with a discrepancy value of 7.5%.

Scientific Reports, Nov 15, 2021

IOP Conference Series: Materials Science and Engineering, 2018

1 ATE-80212044©Asian-Transactions September 2012 Study the Effect of Welding Joint Location on th... more 1 ATE-80212044©Asian-Transactions September 2012 Study the Effect of Welding Joint Location on the Fatigue Strength and Fatigue Life for Steel Weldment Dr.Ali Sadiq Yasir Kufa University / Faculty of Engineering Mechanical Engineering Department IRAQ E-mail:ali_sadiq76@yahoo.com / alis.alathari@uokufa.edu.iq Abstract: The welding process is one of the oldest joining processes between the materials, this paper try to find the effect of welding joint location in the steel on the fatigue strength of steel. The welding process done by electrical arc welding to joining steel samples at different locations at (X/L=0.25, X/L=0.5, and X/L=0.75), where (X) the location of welding zone centre and sample subjected to fully reversed bending stress, then comparing the fatigue test results with un-welded sample. The experimental results show that the welding joint decrease the tensile strength of steel and the fatigue failure strength also decreased specially for that with (X/L=0.5 and X/L=0.75) and failure occur at welding zone, but the sample with (X/L=0.25) had less effected by welding joint and the failure occur at the support not at welding zone. The results show fatigue life affected by the welding joint when draw (S-N) diagram for each sample especially for sample with (X/L=0.5 and X/L=0.75).

419 16 -17 / 3 / 2008 ABSTRACT The increase in using the composite materials in engineering appli... more 419 16 -17 / 3 / 2008 ABSTRACT The increase in using the composite materials in engineering applications make it necessary to improve the properties of composite materials to be able doing its work . One of the method to improve the mechanical properties for fibrous composite materials is Pre-stressing the fibers during room temperature curing process . This process give the more stiffness for composite and make it more stronger and able to withstand the loading subjected to it . This paper show that the pre-stressing fiber process on the glass fiber/epoxy composite materials will give the more strength and make the composite able to carry larger load . The pre-stressing fibers level will be (0 , 2 , 4, 6, 8, 10 , 15 , and 20MPa) that applied on the E-glass fibers with epoxy resin during the curing process with fiber volume fraction about (30%) , and after solidification complete the samples tested under tensile loading by using INISTRON machine . The results show the improvement in...

Nature Publishing group, 2021

This work investigated reasons and factors that cause the failure due to mechanical wear (Erosion... more This work investigated reasons and factors that cause the failure due to mechanical wear (Erosion) for the inside surface of elbows and pipes used in cement transportation which manufactures from low carbon steel and finds out a method for reducing this failure. The technique of Nano-coating layers is used to coat the surface of samples with layers of nanoparticles of tungsten carbides of different thicknesses of (30, 40, and 50 μm). The test was done for these samples by placing them inside the elbow under the same operating conditions, pin on disc test. The results of the test under the same operation condition showed a decrease in erosion rate by 71% for the sample coated with 50 μm of layer, while the results of the pin on disc test showed a decrease in erosion rate by 97% for the thickness of 50 μm as this test is done under ideal testing conditions. The decrease in wear rate for elbow and pipes will increase their life work two times at least and that reduces the cost of maintenance by about 75%. The numerical simulation was also implemented to simulate the erosion profile inside the elbow, and the agreement with experimental results was 90%.

Australian journal of mechanical engineering, 2020

The application of nanotechnology in the welding process has great importance in developing the m... more The application of nanotechnology in the welding process has great importance in developing the mechanical properties of welding joints. The aim of this paper was to investigated the effect of addi...

IOP Conference Series: Materials Science and Engineering, 2021

Nanotechnology is one of the great techniques that helping to considerably improve many technolog... more Nanotechnology is one of the great techniques that helping to considerably improve many technologies and industry sectors such as information technology, homeland security, medicine, transportation, energy, food safety, and environmental science. Low carbon steel is widely used in many applications because it is cheap and it has high workability. However, low surface hardness and impact toughness are its main disadvantages. In this work, the nanocoating of tungsten carbide (WC) has been added to the low carbon steel surface with a thickness of 30, 40, and 50μm by using the thermal spray process with the HVOF technique. The present work aims to investigate the coating layer influence on the hardness and impact toughness. The results showed a significant improvement in the hardness, reaching 94.7%, while the impact toughness improved by 36% for a sample coated with a 50μm comparing with uncoated samples. The improvement in the hardness and impact toughness is due to the good adhesion ...

The problem of failure for elbows and pipes due to the effects of solid particles flow with a hig... more The problem of failure for elbows and pipes due to the effects of solid particles flow with a high velocity, facing a lot of industrial foundations now days. This work investigated factors that cause failure by mechanical wear inside elbows and pipes of cement transportation which manufacturing from low carbon steel (St-52-3) and find out a method for reducing this mechanical wear. Coating with layers of nanoparticles of tungsten carbides (WC) using a thermal spray process with a high-velocity oxy-fuel technique (HVOF) is one of those methods. The coating process was done for samples from the same material of elbow and pipe material. Some tests were done for these samples with different coating thicknesses (30, 40, and 50 µm) by placing them inside the elbow as well as standard wear tests (pin on disc). The results showed a decrease in the mechanical wear for the sample coated with 50 µm of WC layer by 71% compared with that without coating, while the results of the pin on disc test...

Mechanical Engineering Research, 2013

International Journal of Engineering & Technology, 2014

The fatigue failure is the reason of most mechanical failure for engineering materials. This work... more The fatigue failure is the reason of most mechanical failure for engineering materials. This work tried using the nano-coating technique to coat the steel bars and study the effect of this coating layers on fatigue life of steel. The Zinc Oxide (ZnO) used as it cheap and available in most labs of nanotechnology. The coating process done at different time of coating to get different thickness of coating layers. The result of fatigue tests for coated samples show increased in fatigue life for samples that coated for long time (thick layer of coat), and the increasing if fatigue life may reach to 4-times of its fatigue life for un-coated samples. Keywords: Fatigue, Fatigue Life, Steel Bars, Nano-Coating Technology, ZnO Coat.

Kufa journal of Engineering, 2018

Tires are considered important components of the vehicle by which the vehicle can move on the roa... more Tires are considered important components of the vehicle by which the vehicle can move on the road. The continuous development in the transportation requires improving tires to suit the modern requirements of the transportation. This work includes studying the effect of using the pre tension technique to improve the flexural and adhesion properties of bead ply in rubber tires. Pre-tension levels ranging between (01250 MPa) were applied on each single reinforcing wire at room temperature before the vulcanization process. The results showed that the increasing in maximum bending strength, bending stiffness, and maximum shear strength by (26 %) due to pre-tension. The single fiber pull-out test results show that the debond shear strength was increased by (27 %) pre-tension on steel wires.

This paper tries to investigate the effects of adding titanium dioxide nanoparticles (TiO2 NPs) t... more This paper tries to investigate the effects of adding titanium dioxide nanoparticles (TiO2 NPs) to the welding joints in order to improve the mechanical properties of such welding joints of (St-37) low carbon steel base plate by means of electric arc welding. The cold spray coating method of the TiO2 NPs is used for the welding joints during the welding process. Three weight fractions of TiO2 NPs are used (0.75, 1.5, and 2) % respectively. The selected samples from the tensile strength, hardness, and microstructure tests are examined by Scanning Electron Microscope (SEM). The SEM images reveal that there are homogenous regions in the welded joints cross-section in comparison with specimens that contains no TiO2 NPs addition. Improvements in tensile strength and hardness values of the welded joints with an increase in TiO2 NPs concentrations are observed. It is found the average value of ultimate tensile strength of the welded sample without TiO2 NPs is (435.457) MPa, while the avera...

… and its Applications (IDC), 2010 6th …, 2010

This paper is concerned with the Improving Space Time Diversity In a Fixed Point-to-Point link Us... more This paper is concerned with the Improving Space Time Diversity In a Fixed Point-to-Point link Using LMS Based Interference Cancellers, carrying SDH signals with 30 MHz channel spacing. A system model is presented based on a proposal to achieve higher ...