Journal of Simulation and Analysis of Novel Technologies in Mechanical Engineering
Volume:13 Issue: 2, May 2021

In this research, the failure of a stud bolt was studied. This bolt is under periodic loading, in a multi-stage compressor. The undesired vibration of the system causes vibration load on the bolt.  The bolt was modeled in Abaqus software and the generated stress was calculated. To determine the dynamic load on the bolt, the vibration of the system was measured by a digital vibration sensor and this load was simulated in Abaqus software. The boundary condition and loading were considered similar to the real working condition. The failure and fatigue of the bolt was investigated in the periodic loading. The factors such as the shank diameter, chamfer radius and material were changed and the corresponding response of sample and change in stress was studied. The most probable points of the bolt for failure were found and the effected of the reduced shank diameter on its life was considered. In the initial design, the shank diameter was considered 12 mm. The results shown that by decreasing the shank diameter, the stress first decreases and then increases and the minimum of stress occur at the shank with a diameter of 11.47 mm. Also, by increasing the chamfer radius, the stress first increases and then decreases and the minimum of stress occurs at the chamfer radius of 33 mm.

In the present research, an artificial neural network was designed and conducted to thermodynamically analyze performance variables of two-shaft radial flow gas turbine model GT185. To do this, firstly the needed tests were conducted at different operating conditions and the essential variables like temperature, pressure, rotational speed, mass flow rate which totaled 17 inputs were recorded. Then, using the relations regarding radial flow turbines and the laboratory results, performance variables including compressor, gas turbine and free turbine power and efficiency and finally the cycle heat efficiency were calculated. After calculation of these variables for all laboratory data, a neural network was designed and tested using Matlab software toolbox in order to facilitate the obtaining of performance variables in different operating conditions. In this network, highest errors absolute values of training, verification and testing data were 0.32, 0.86 and 1.39 respectively. Error value of the produced function of sample laboratory results and manual calculations was less than 0.1%

This study investigates the dynamic stability of the Euler-Bernoulli functionally graded (FGM) nanobeam based on the nonlocal elasticity theory while considering surface effects. Nanoparticles pass over nanobeam sequentially with a constant velocity, and the nanoparticle inertia is also considered. A thermal gradient with constant temperature changes is applied to this nanobeam. The functionally graded nanobeam properties, including Young’s modulus, density, surface residual stress, and surface modulus are taken by the power law. The classical equations of motion are obtained by applying the Hamilton’s principle according to the energy method. The governing equations are extracted using nonlocal elasticity theory, and the surface effects are taken by Gurtin-Murdoch theory. The dynamic stability graphs will be presented on nanoparticle mass-velocity coordinates. This article investigated the small scale effect parameter, temperature changes, Pasternak environment shearing and elastic constants, and the volume fraction parameter in power law. The results show that increasing Pasternak foundation constants increase the functionally graded nanobeam stability, and increasing small scale parameter reduces its stability. Increasing nanobeam temperature shifts the functionally graded stability region of nanobeam towards faster nanoparticle velocity, which indicates a higher dynamic stability for the nanobeam.

The purpose of this study is to investigate the vulnerability of Shiekh Bahaei’s bath under the blast wave. This study was performed as a numerical study using software analysis. The method of three-dimensional nonlinear finite element analysis was selected by Abaqus software. Nonlinear dynamic analysis method was selected to determine the moment-to-moment response of the structure to the explosive load. The Drucker Prager criterion is also used to model building materials in Abaqus software. The accuracy of finite element modeling results was ensured by comparing the modeling results with the laboratory sample. The finite element model of Shiekh Bahaei’s bath was modeled in Abaqus software and nonlinear dynamic analyses under the blast wave were performed. Then, the results were compared in the form of tensile damage meters and displacement-time diagrams. Based on the results of this study, the location of the breakdown and the amount of displacements in different parts of the bath under the blast wave were determined.

Titanium (Ti) used for various application due to its light, durable and polished silver-white element. Titanium has two forms of allotropy called rutile and anatase, due to white color, slow-melting point in uniform distribution and diffusion in other compounds. It is known for making paper, plastics, rubber and various other materials. Therefore, regarding its use and high application in this paper we reviewed the conventional and advance application of Ti sheet. The presence of small amounts of impurities such as nitrogen, carbon and hydrogen in which are soluble in the metal, causes the mineral fragility of the metal and prevents its commercial exploitation. The purpose of this study is to introduce and application of titanium in various industries. The main use of titanium in the industry is in the form of metal and titanium dioxide nanoparticles, the use of metal is not used much due to problems in its preparation and purification, but instead, the use of oxide in the form of TiO2 is widely used in industry. Therefore, 90% of the primary industries are consuming titanium oxide. The human body easily accepts titanium because it has been proven to be more biocompatible than stainless steel or cobalt chromium (CoCr). In addition, titanium has a higher fatigue strength than many other metals which helps to transform it as a desired material in orthopedic and dentistry applications.

In recent years, research centers and researchers have focused their efforts on producing vehicles with clean, compact, easy-to-transport, and low-emission vehicles. In this regard, many designs and ideas in the field of unicycle robots have been presented. Single-wheeled robots take up little space and are able to move in narrow spaces. The main purpose of this article is to significantly reduce the dimensions of the unicycle robot and to reduce its internal components, based on which the robot body is designed in the minimum possible dimensions. The mechanism design of this robot, unlike other robots, has its own difficulties and complexities. Using a wheel to move the entire assembly, including controllers, drivers, motors, and many other parts, requires a very precise design for the robot chassis. This design, in addition to including all the components of the robot, must organize the internal components in such a way that the center of gravity of the robot has as much inherent balance as possible. On the other hand, the design of the reversal mechanism in this structure is unique and is completely different from other reversal mechanisms in other unicycle robots. These changes caused a significant reduction in the dimensions and construction costs of this robot compared to similar robots. Using the CC3D controller and the LibrePiolet-GCS software, based on the maneuvers made for the robot, the necessary coefficients for the proportional-integrator-derivative controller were tested so that under them The robot is controlled and selected correctly and in balance. With the adjustment for the controller coefficients, the next maneuvers of the unicycle robot with a rate of over 85% were performed successfully.