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Go to Editorial ManagerThe research aims to make a comparison between two highly used aluminum alloy though studding the effects left by the microwave furnace wavelengths by (middle dry and amid aqueous solutions) on the mechanical properties and estimated fatigue life of highly resistant widely use aluminum alloy AA 7075-T6 and AA 2024-T3. Since the microwave effect differ from other heating methods through its effects (Heat Transfer) r heating methods effects on the surface of the alloy, which might change some of its properties as well as resistance to fatigue, also to see how this effect changes from alloy to another through this study. The results show some great effects on both mechanical properties and estimated fatigue life for both alloys but with different levels. This new technique is differing from other traditional heat treating ones that is simple, cheap and fast accurate method than the other techniques.There is a common misconception about the use of minerals in microwave ovens and the concept is unscientific and based on false grounds and simplest proof of that is that most of these ovens are built from the inside metal fully, how dangerous this is consistent? This research aims to focus on and remove those problematic and misconceptions.
Improving fatigue life is one of the most important issues in mechanical design; an investigation has been conducted on Al 2017-T4. Group of samples have been machined and prepared, some of specimens have been treated using the ultrasonic impact treatment (UIT) with one line peening. The fatigue tests were carried out under constant and variable amplitude (R=-1) at ambient temperature, in order to find out the fatigue life S-N curve and strength after treatment. It has been found significant increasing in strength after it was treated by (UIT). The fatigue strength is improved after treatment up to 4.16% at 107 cycles, enhancement are present with 24% and 18.78% for the cumulative fatigue lives low-high and high–low respectively. These results also show a strong tendency of increasing of fatigue strength after application of (UIT) with increase in mechanical properties of material used.
Recently, considering polymer composite in manufacturing of mechanical parts can be caused a fatigue failure due to the very long time of exposure to cyclic loading and may at environmental temperatures higher than their glass transition temperature; therefore, in this paper, a comprehensive investigation for bending fatigue behavior at room and elevated temperatures equal to 60 °C, 70°C, and 80 °C will be done. Rotating bending test machine was manufactured for this purpose supplied with a connected furnace to perform fatigue tests at elevated temperatures. The obtained results appeared that the increase in applied stress and temperature caused a clear reduction in fatigue life; also the addition of carbon nanotubes enhanced the fatigue life at different temperatures by 183%, 205%, 218%, and 240%, respectively while the addition of short carbon fibers improved fatigue life by 324%, 351%, 387%, and 415%, respectively. As well as, Polyamide 6,6/carbon fiber composite appeared fatigue limit at temperatures equal to 20°C and 60°C and stresses approximately equal to 55 MPa and 38 MPa respectively.
Pressure vessels are the heart of plants and oil refineries stations. In many engineering applications such vessels can be subjected to periodic loading either internally due to the charging and discharging process or externally due to the excitation from other nearby components such as pumps, compressors or from seismic. So that in spite of a good design according static assumption it may be critical in dynamics. In this work a horizontal pressure vessel with accessories subjected to liquefied petroleum gas pressure LPG is considered. Three models of different head types are investigated herein namely; Deep torispherical, Elliptical 2:1 and Hemispherical. The design and material selections are chosen as per ASME. For practical service many accessories are attached to the vessel such as manhole, supports, inlet and outlet opining. Finite Element method via ANSYS R18.2 is introduced for the numerical analysis. The fatigue life in case of fully reversed cyclic loading are estimated and located. Vibration characteristics such as mode shapes and natural frequencies for the lowest five modes are evaluated and compared. It is found that the fatigue life can be increased as higher as 180% for hemi- spherical head as compared with deep torispherical head pressure vessel and the lowest four natural frequencies are nearly identical for all models, however significant change observed in the fifth natural frequency.
Due to their very good mechanical properties of composite materials which led to a huge increase in its application in a lot of fields.Epoxy/ PS(polysulfide) composite materials behavior in fatigue was reported. different weight fraction of PS (2%,4% and6%) were studied .Surface roughness properties of the blended composites were found for all weight fraction of PS and their fatigue properties are studied .Fatigue test was carried with rotating bending method. The loading in the test was sinusoidal wave type. The loading wave ratio is R = -1 and the frequency of loading is applied to avoid temperature rise with a frequency equal to 5Hz. Fatigue strength ,fatigue life and fatigue limit of the tested composites from standard curves are calculated. The addition of PS resulted in an enhancement in the fatigue values and cause the surface roughness to decrease at a considerable rate, the blend hardness is reduced considering shore A test.
thetic socket, is due to its fiber strength and hardness, and low cost, but there are other more important things which must be considered than these specifications which are1the health1and safety. In this research fiberglass is replaced with monofilament fiber in order to be safe to on makers and users of this socket. In this paper two models of lamination manufacturing have been made and compared in terms of mechanical properties and fatigue life. The first is available and consists of: (4 perlon, 2 fiberglass and 4 perlon), The second is proposed lamination which consists of: (4 perlon, 1 cotton, 1 monofilament and 4 perlon). Simulations were conducted on the made socket made of two types of lamination by using ANSYS 14.5 to show the distribution of stresses, the amount of deformation and less safety factor for both cases. The results show an increase of 42% in the Young's modulus and a decrease in tensile stress and yield stress by 10.8% and 46% respectivel, As for the stress endurance it witnessed an increase of 140%.The simulation results show a decrease in the deformation by 40.7% and an increase in the minimum value of the safety factor of 0.323 to 1.05.
The effects of the ultrasonic peening treatment (UPT) on the rotating bending fatigue behavior and the behavior of the vibrations of alloy steel DIN 41Cr4 were studied. Hardness test, Tensile test, Constant amplitude fatigue tests, and the vibrations measurements have been carried out on the specimens. Also, the fracture surface was examined and analyzed by a Scanning Electron Microscope (SEM). The results of the investigations, e.g. stress to number of cycles to failure (S-N) curves, fatigue strength improvement factor was 7%. The decreasing percentage of maximum Fast Fourier Transform (FFT) acceleration of the ultrasonic peened condition compared to the untreated conditions was 45%.