Dynamic Buckling of Cylindrical Composite Panels Under Axial Compressions and Lateral External Pressures

Nimonic 75 and Inconel 600 alloys are the Nickel-based superalloys which are used in manufacturing gas turbine components. In the current research, a superalloy Ni-based Nimonic sheet and Inconel 600 were used, joint by resistant spot welded (RSW) machine at currents of 2, 4, and 6 kA, pressure of 5 and 7 bar, and times of 0.6, 0.9 and 1.2. Non- destructive inception methods and light and scanning electron method (SEM) and light optic microscope (LOM) were used to evaluate joints' quality. Shear and micro-hardness test was used to check the mechanical properties of the joint. The findings indicate that the most appropriate welding connection of inhomogeneous points at the current of 4 kA was the holding time 0.9 second and electrode force 7bar. The analysis of microstructure consisted of 3 welding zones which are affected by heat and the base metal. The warm corrosion scanning microscope test results at 600 °C and 800 hours confirmed that the existence of a chromium oxide layer on the surface of the superalloy, which has the main role in protecting the piece in the output temperature.

Section: Resultsmentioning

confidence: 99%

“…Nowadays, industrial designers need lots of more robust and more corrosion-resistant materials [1,2]. Among all engineering materials, aluminum alloys and composites are mostly used for anti-erosion and lightweight structures [3][4].…”

Section: Introductionmentioning

confidence: 99%

Microstructure Investigation, Hot Tensile and Hot Corrosion of IN600 to Nimonic 75 heterogeneous Connection in Spot Welding

Kaleybar

Safari

Raoofi

et al. 2021

“…The Ilijma's invention of carbon nanotubes [1] opened a new way to conduct research of nanotechnology's science. Lots of applications and the outstanding physical, mechanical, and electrical properties of carbon nanotubes and graphene [2][3][4][5][6][7][8][9][10][11][12], make them the subject of intensive studies. Increasing research efforts of graphene has been enticing since its discovery [13].…”

Section: Introductionmentioning

confidence: 99%

Fracture Analysis of Vacancy Defected Nitrogen Doped Graphene Sheets Via MD Simulations

Jahromi

Mehdipour²,

Firoozi

2021

The novel hexagonal monolayer sheet of carbon atoms, graphene, has attracted great attention due to their exceptional electrical and mechanical properties. Their phenomenally high strength and elastic strain, nevertheless, can be altered by structural defects due to stress concentration. In this paper, the fracture behaviour of graphene sheets and nitrogen doped graphene sheets with vacancies were investigated using molecular dynamics (MD) simulations at the different temperatures of 300K, 500K, and 900K. The results reveal a significant strength loss caused by both the defects and vacancies and doped nitrogen in graphene. The deformation process of graphene at various strain rate levels, with regard to the failure behaviour, is discussed. The validity of the proposed MD simulations is verified by comparing the simulation results with the available predictions from the quantized fracture mechanics.

“…Due to some advantageous features of composites such as high strength-to-weight ratio, being resistant to fatigue and so on, they are widely used in different engineering fields. The thermal buckling and post-buckling of geometrically perfect and imperfect hybrid laminated composite plates reinforced with shape memory alloys (SMA) subjected to a uniform thermal loading are investigated by a semi-analytical finite strip method by Rostamijavanani et al in 2021 [13,14].…”

Section: Introductionmentioning

confidence: 99%

Numerical Study of the Effect of Different Variables on the Cooling of a Flat Plate Using a Synthetic Jet

Nabavi

Jafari

2021

A synthetic jet is caused by the periodic motion of a diaphragm within a cavity. There is one or more orifices or outlets in this cavity. The main advantage of this type of jet compared to a continuous jet is that the synthetic jet is composed of transverse flow, and therefore, it does not need a continuous source of fluid, unlike the continuous jet. In recent years, synthetic jets have received a great deal of attention so that they have been used in a wide range of applications such as controlling separation and turbulence, besides, the cooling of electronic equipment and propulsion. In the present study, the jet is placed perpendicular to the flat plane with constant heat flux, thereafter, the effect of some geometric parameters were evaluated numerically such as the ratio of the distance between the jet and the impinging plate to the nozzle width, the ratio of the impinging plate length to the jet nozzle width, the ratio of cavity width of the synthetic jet to the nozzle width, the ratio of the cavity height to the nozzle width, the angle of the impinging plate, besides, the diaphragm specifications including amplitude and frequency of the jet diaphragm in heat transfer using OpenFOAM open-source software. The results show that the frequency and the length of the impinging plate are the most effective parameters, respectively, in terms of the diaphragm and geometry.