@amin.moslemi2020@gmail.com
Department of Mechanical Engineering
Imam Hossein University
Mechanical Engineering in Applied Design (Solid Mechanics).
Ceramics and Composites, Mechanical Engineering, Mechanics of Materials, Industrial and Manufacturing Engineering
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Hossein Rahmani, Mohammadreza Elhami, and Amin Moslemi Petrudi
River Publishers
In this research, while investigating the vibration analysis of rotary axes, we specifically investigate the rotor of a turbofan engine used in the industry. The features of this rotor range are high-performance, lightweight, and low-vibration range. These three factors are in contradiction with each other, resulting in a thorough examination of the total vibration of the complete turbofan rotor. To achieve this, various parameters such as the concentration of properties, rotational inertia, gyroscopic torque, rotational loading, effects of unbalanced mass, crevillous effects, bearing flexibility, etc. have been studied in modeling. The rotor’s natural frequencies, along with the critical velocity, are plotted as well as the shape of its modes. The software is required to perform the computations written by Ansys software and after ensuring its accuracy.
Masoud Rahmani, Alireza Naddaf Oskouei, and Amin Moslemi Petrudi
Elsevier BV
Abstract Among the intrinsic properties of some materials, e.g., foams, porous materials, and granular materials, are their ability to mitigate shock waves. This paper investigated shock wave mitigation by a sandwich panel with a granular core. Numerical simulations and experimental tests were performed using Autodyn hydro-code software and a shock tube, respectively. The smoothed particle hydrodynamics (SPH) method was used to model granular materials. Sawdust and pumice, whose properties were determined by several compression tests, were used as granular materials in the sandwich panel core. These granular materials possess many mechanisms, including compacting (e.g., sawdust) and crushing (e.g., pumice) that mitigate shock/blast wave. The results indicated the ineffectiveness of using a core with low thickness, yet it was demonstrated to be effective with high thickness. Low-thickness pumice yielded better results for wave mitigation. The use of these materials with a core with appropriate core reduces up to 88% of the shock wave. The results of the experiments and numerical simulations were compared, suggesting a good agreement between the two. This indicates the accuracy of simulation and the ability of the SPH method to modeling granular material under shock loading. The effects of grain size and the coefficient of friction between grains have also been investigated using simulation, implying that increasing the grain size and coefficient of friction between grains both reduce overpressure.
Mehdi Babaei, Somayeh Mollaei, Amin Moslemi Petrudi, Maysam Jalilkhani, and Ionut Cristian Scurtu
EDP Sciences
This paper presents two simple and robust technique for response estimating of single-degree-of-freedom (SDOF) structural systems. The impulse method, because it is formulated based on the fundamentals of dynamics; especially, the linear impulse concept, and also the energy method, because the main idea of this method is inspired by energy conservation principles. These methods can strongly cope with linear damped systems for which damping ratio ζ is greater than 0.01. Assessment of SDOF dynamic systems under any arbitrary excitations is easily possible through the proposed methods. There is no error propagation through the solving process. The numerical example reveals the simplicity and robustness of the new technique compared to Duhamel’s integral and similar techniques. Finally, a numerical example is investigated to demonstrate the efficiency of the algorithms. The most famous record of El Centro ground motion is applied to the systems. The obtained results show that the new algorithm works exactly enough to compete with a conventional method such as the Duhamel integration method and the Newmark-β method. A comparison between the results of this method with the solution methods used by other researchers is shown to be a good match.
Masoud Rahmani, Amin Moslemi Petrudi, and Mohammad Reza Pourdavood
International Information and Engineering Technology Association
In this paper, the free and forced vibration of a functional rectangular plate in contact with a turbulent fluid is investigated. Functional plates have been considered due to their high thermal resistance to residual stresses. The geometry of the problem is that one side of the reservoir in which the fluid is placed is covered with a plate of Functionally Graded Material (FGM). In order to approximate the displacement of the plate, assuming the third-order theory of shear deformation, trigonometric harmonic test functions are used, which determine the boundary conditions of the simple and fixed plate support. In the equations governing fluid oscillating behavior, the potential velocity of the fluid is obtained by determining the boundary conditions of the fluid in the form of February series functions. To achieve the natural frequency of the plate in contact with turbulent fluid and the shape of the vibrating mode, the Rayleigh-Ritz energy method is used based on the minimum potential energy. In order to check the accuracy of the method used, the results of analytical solution after solving the equations by coding in Wolfram Mathematica software have been compared with numerical solution of Abaqus software and then with accurate results in references, which shows the appropriate accuracy of the solution. Finally, the effect of volumetric coefficient parameters, volume ratio, length ratio, plate thickness ratio, fluid height, reservoir width and boundary conditions on the natural frequency of the plate in contact with turbulent fluid has been investigated and analyzed.
Pourya Fathi, Amin Moslemi Petrudi, and Ionut Cristian Scurtu
IOP Publishing
MohammadAli Moslemi Petrudi, Mehdi Saeed Kiasat, Manouchehr Fadavi, and Amin Moslemi Petrudi
The Netherlands Press
Ships are always prone to fatigue through high periodic loads, usually caused by waves and changing load conditions. So, fatigue is an important factor in design. One of the reasons for fatigue in welding parts is variable bending loads. In this paper, a specimen of low-carbon steel T-Bar profiles is used, along with plates of the same type of steel that have been welded by the manual electrode welding process. To determine the distribution of static and dynamic forces created by welding, the specimens were subjected to bending (three-point loading) and tensile tests, and finally fatigue tests. The T-Bar Steel profile has more tolerance for fatigue loads than welded. The load T-Bar profile has not failed until the two million cycles, while the welding specimen has failed in about 3×105 cycles. Finally, strong penetrating welds should be used if a stronger welding joint is required.
Masoud Rahmani and Amin Moslemi Petrudi
Gruppo Italiano Frattura
Sandwich panels with polymer composite and light core composites are widely used in aircraft and spacecraft, vessels, trains, submarines, and cars. Due to their high strength to weight ratio, high stability, and high corrosion resistance, these structures have become particularly important in the industry. Reduction in impact energy, shock waves, and noise in many industries, including the automotive and military industries. Porous materials have always been the focus of attention due to their shock-reducing effects in various protective applications. For this reason, the study of physics governing shock propagation problems in porous media is of particular importance, and the complexity of the governing equations also results in the numerical solution of these equations with many computational problems and costs. In this paper, shock wave damping is investigated numerically and experimentally in aluminum blocks with porous grains scattered inside aluminum. The deformations of the specimens in numerical simulation and experimental testing have been compared. The results show that this material behaves similarly to the aluminum foam in both static loadings (practical pressure testing) and dynamic loading (explosion simulation) results, again similar to aluminum foam.
Amin Moslemi Petrudi, Khodadad Vahedi, Masoud Rahmani, and MohammadAli Moslemi Petrudi
Gruppo Italiano Frattura
Simulation and analysis of the projectile impact and penetration problem and its effects are among the practical topics that can be used to design bulletproof panel and military equipment, construction of impact and penetration resistant structures, design of projectiles with appropriate penetration strength and High performance noted. One of the most important parameters affecting penetration is the impact velocity of the projectile. The mechanism of penetration varies in different speed ranges. In this paper, Ansys Autodyn software is used for intrusion simulation. The simulation carried out in this study is based on the accuracy and physical conditions of the problem and the compatibility of numerical simulation with the governing analytical relationships indicates the validity and accuracy of the assumptions made in the simulation. In this study, we selected materials such as material behavior, grating, contact surfaces, and controls, as well as collision of the blunt projectile with angles of 0º,15º,30º,45º by of high velocity impact 1000 m/s with the same mass and diameter and shape of the projectile nose and properties. Ceramic materials are discussed. The result of the numerical simulation comparison shows relatively good agreement between them.
Pourya Fathi, Alireza Naddaf Oskouei, Khodadad Vahedi, and Amin Moslemi Petrudi
Gruppo Italiano Frattura
Composite structures in the field of advanced and modern structures in engineering design and according to high specification of composite materials such as high strength to weight ratio use in various industries such as aerospace, marine. One of the most important fields that Researchers have paid less attention to that is to investigate the effect of stacking sequence on the strength of mechanical joints under impact loading. In view of changing the mechanical properties of composite materials by changing the arrangement of layers, in this study, the effect of different orientation of layers on the strength of pin joints in glass-epoxy composites under low-velocity tensile impact has been investigated. Using the Abaqus software and the finite element method, the impact simulation and the force applied to the mechanical joint were analyzed. To evaluate the simulations, the results of the finite element method have been compared with the experimental results. By observing the results, the introduced finite element model is well-considered and is well-matched with the result of the experimental dataset, which made it a valuable tool for predicting the strength of multi-layer composite materials under impact loadings. Using the results of the model, one can analyze the distribution and type of stress and strain in each layer of composite.
Masoud Rahmani and Amin Moslemi Petrudi
Periodica Polytechnica Budapest University of Technology and Economics
Some materials, due to their inherent properties, can be used as shock and wave absorbers. These materials include foam and porous materials, in this study, specimens were made by casting aluminum on porous mineral pumice. Which can replace aluminum foam in some applications with lesser cost, at first, the material is compared with aluminum foam using compression test and quasi-static loading diagram. Which compares the diagrams of these two materials showing the similarity of their behavior in quasi-static loading. Initially, the elastic bending of the walls causes an elastic region in the stress-strain curve of the material. Then, the plastic collapsing of the cells forms a large and relatively smooth region along the elastic and after the plastic collapse of the cells, the area known as foam densification begins where the density of the foam closer to the density of its constituent material causes a sudden increase in the stress level in the specimen. These steps have also been seen in the quasi-static loading of aluminum foam. Then, by using numerical simulations with ANSYS AUTODYN and the shock tube test the ability of these specimens were investigated to reduce the shock wave. The behavior of the material in this case is also very similar to the results of previous studies on aluminum foam.
Amin Petrudi and Masoud Rahmani
International Information and Engineering Technology Association
Received: 10 December 2019 Accepted: 21 February 2020 Composite laminates are widely used in civil engineering, aerospace, shipbuilding and the military industry because of their high strength and rigidity to their high weight ratio, good fatigue resistance and high energy absorption fineness. The mechanism of degradation in composites is very complex and one or more degradation modes may occur in the composites at the same time. In this paper, multi-layer composite degradation with stress concentration due to internal hole is investigated numerically and analytically. The miso-scale model is used to investigate the problem. Fortran and Ansys software have been used to analyze the problem. The usermat code is embedded in Fortran software and linked to Ansys software. The present paper solves the stress induced multilayers in the present study, and compares the results of this method with those of other researchers. Stress and damage contours have been reported. it is shown Change of the diameter of the central open-hole not only the effect on possible damage, damaging rate, progressive damage but also effect on the strength of the composite laminates is also indicated.
Amin Moslemi Petrudi and Masoud Rahmani
River Publishers
In this research, the discrete element method has been used to analyze wave propagation and to investigate the factors affecting wave reduction in granular soils. The method of discrete elements is important because of the possibility of preparing completely similar specimens and examining the effect of changes in a certain parameter on the Behavior of the specimens. This method also provides an understanding of the changes that have occurred at the micro-scale of granular materials that are not achievable with other laboratory and numerical methods. To model the specimens, a set of disks with specific granulation has been used for two-dimensional studies. PFC 2D software has been used to perform simulations and related analyzes such as interparticle force. The DEM code in MATLAB is used to check the wave depreciation. In this research, the optimization process was performed using experimental data and the Taguchi method using the DEM method. The results of this study show that there is a direct relationship between the number of particle set contacts and the wave propagation speed. Also, material properties such as particle density are the most important parameters affecting wave velocity. The results of the method (DEM) are done with PFC 2D software and a comparison between the results of this method with the solution methods used by other researchers is shown to be a good match.