finite element method

In cement production, rotary kilns are essential, particularly in clinker manufacturing. The spring plates, fabricated from St37-2 steel, connect the girth gear to the kiln shell and play a crucial role in the structural integrity of the kiln. This study numerically analyzes and optimizes the stress distribution across spring plates used in the Kufa cement plant (Najaf, Iraq), under varying operational conditions. Using finite element modeling (ANSYS 2022/R1), stress distributions for the standard spring plate design (S), three existing designs (d1, d2, d3), and three proposed designs (P1, P2, P3) were compared. Sensitivity analysis was conducted across five filling conditions: (1) 100% design load, (2) 100% practical load, (3) 90% practical load, (4) 80% practical load, and (5) 70% practical load. The proposed P3 design demonstrated the best performance, reducing the maximum stress concentration at critical locations by 51.86% compared to the standard design, with maximum stress values of 154.06 MPa (P3) versus 320.08 MPa (S) under 100% design load. The sensitivity analysis confirmed that stress levels decreased with reduced kiln loads, enhancing the service life of the spring plates. This study underscores the importance of design modifications to minimize stress concentration and improve the operational durability of rotary kilns.

Nowadays, with the growing emphasis on clean energy and renewable resources, the use of permanent magnet (PM) electric motors has garnered significant attention. One of the latest types of PM motors is the Vernier permanent magnet motor (VPM). This paper focuses on analyzing and evaluating a spoke-type Vernier permanent magnet motor (SVPM). The main innovation and contribution of this study is the introduction of a dual-stator configuration for the spoke-type Vernier permanent magnet motor. Dual-stator spoke-type Vernier permanent magnet motors (DSSA-PMVM) typically lacking flux barriers on their rotors. In this research, a novel design incorporating magnetic flux barriers into such motors has led to the development of a new motor architecture. The dual-stator spoke-type Vernier permanent magnet motor with flux barriers (DSSA-FBPMVM) effectively addresses some of the challenges inherent to traditional Vernier motors. Vernier motors are generally characterized by high torque output at low speeds; however, a notable drawback is their low power factor. The DSSA-FBPMVM not only enhances the torque output compared to the SVPM within the same volume but also overcomes the low power factor issue of the SVPM, achieving a relatively desirable power factor. The analysis and evaluation method used in this study is based on the two-dimensional finite element method (2D FEM).

Rotating cylindrical shells have a wide range of practical applications; however, they are prone to vibrations. Despite numerous theoretical studies on vibration characteristics of rotating cylindrical shells, experimental validation remains limited.  Using non-contact vibration sensors for an experimental study offers significant advantages, such as eliminating mass effects and avoiding complex wiring associated with attachment to rotating shells. However, achieving an adequate data acquisition frequency by non-contact sensors in modal analysis of rotating cylindrical shells necessitates deploying multiple sensors circumferentially, which makes it costly and complex. This difficulty could be mitigated by correct shell selection to enable experimental validation of theoretical studies. The primary objective of the present study is to determine with which dimensions and rotational velocities, an experimental result of vibration characteristics for a rotating cylindrical shell could be attained by fewer non-contact sensors, which could be interpreted as a first pace toward experimental validation of theoretical methods. To achieve this innovative goal, a parametric study was conducted using an accurate finite element method (FEM) in ANSYS to illustrate how rotational velocity and dimensions affect the required number of sensors. Using the results of the parametric study, optimum values of rotational speed and dimensional parameters have been determined in a way that the experimental vibration analysis could be accomplished with a minimum number of required circumferential non-contact sensors. In the case of the present study, the number of required circumferential sensors is reduced from about 200 for an unsuitable choice to 24 for the choice of the present paper.

Flux-barrier permanent magnet Vernier motors are among the latest magnetic motors developed and optimized in the industry. In these motors, the arrangement of magnets plays a critical role and significantly impacts on the torque density in the rotor-stator gap. This is because the motor's output torque increases with an enhancement of magnetic flux intensity in this gap. The magnetic gearbox effect in the flux-barrier permanent magnet Vernier motors, along with flux modulation, is one of the most critical factors in the design and construction of these motors. Flux modulation in the air-gap generates high torque at low speeds. In this study, inspired by the concept of magnetic gearboxes and by adding a modulation ring to the air-gap of this motor, a novel design for flux-barrier permanent magnet Vernier motors with a gearbox is presented. Using the two-dimensional finite element method (FEM), it has been demonstrated that the designed motor achieves significant improvements in average output torque and power factor compared to previous designs.

The article presents the results of research on design of a high-speed turbine, calculation of flow and losses in its flow passage. In the course of the study, optimization algorithms were used to change the geometric parameters of a three-dimensional parameterized flow section in stationary and non-stationary settings in order to improve the required integral characteristics of the turbine. Numerical calculations were performed in Ansys Workbench software package on heterogeneous Polytechnic – RSK Tornado cluster of SPbPU. The developed flow passage of the turbo drill stage exceeds the parameters of the original model. This model, compared with the original version with the same pressure drop, allowed an increase in turbine efficiency with a significant increase in torque (+47%). In order to validate the results of numerical calculations using computational fluid dynamics methods, preparations are being made to perform experimental studies of the designed models on a water experimental unit.

Three commercial stents (Palmaz-Schatz, NIR, and BioMatrix) with either an open-cell (20% open-cell) or a closed-cell (80% closed-cell) design, and one new hybrid stent design were numerically modeled using the ABAQUS/Explicit finite element software (Dassault Systèmes, France) to compare their behaviors during deployment in a stenotic artery. The ABAQUS/Explicit dynamic explicit solver was utilized to efficiently capture the complex interactions between the balloon, stent, artery, and plaque during the stent expansion process. The effect of changing the material from stainless steel (SS 316L) to cobalt-chromium (CoCr) and platinum-chromium (PtCr), as well as the reduced thickness of struts from 0.1 mm to 0.08 mm, were investigated. The new hybrid stent design featured reduced axial strut spacing (from 1.2 mm to 0.8 mm), larger corner radii (from 0.2 mm to 0.3 mm), and smaller amplitudes in the ring (from 1.0 mm to 0.8 mm). For the simulations, a balloon-stent-artery model with plaque and average blood pressure of 80 mmHg was used. The results showed that the new hybrid stent did not perform worse in any of the studied biomechanical parameters compared to the commercial open-cell (20% expansion) and closed-cell (15% expansion) stents, and exhibited better performance in maximum expansion (22%) and recoil responses (5% recoil). Changing the material in the new hybrid stent from SS 316L to CoCr or PtCr improved the biomechanical behavior, such as expansion (25%), recoil (3%), and dogboning (0.9), but increased the maximum von Mises stress on the artery-plaque system by 18%. Reducing the strut thickness from 0.1 mm to 0.08 mm decreased the maximum stress on the artery-plaque system by 12%, but undesirably increased dogboning (1.1) and recoil (7%).

The presents study numerically investigates the fiber-reinforced polymer (FRP) retrofitted short-damaged reinforced concrete (RC) columns subjected to axial compression load. The main parameter considered to evaluate the effectiveness of FRP retrofitting on circular columns with different aspect ratios, concrete grade, and FRP material. To simulate the behaviour of a short RC column under a uniaxial compression load, a finite element model of the column was developed. The model was then modified to simulate the various level of damage to the column and the behaviour of the column under uniaxial load. The effectiveness of FRP retrofit was studied comparing the behaviour of the retrofitted column to the damaged column. For M20 concrete column retrofitted with carbon fiber reinforced polymer (CFRP) showed a higher strength (2 to 3 times) than glass fiber reinforced polymer (GFRP) retrofitted columns. For M30 concrete, the range is quite similar (1.5 – 2.3 times more). The effectiveness of both FRPs retrofitted columns increases with increasing aspect ratio from 2 and 3, but slightly decreases for an aspect ratio of 4 compared to the damaged specimen. The maximum effectiveness achieved for CFRP retrofitted columns is of 19.45% and for GFRP retrofitted column is of 10.71%, and the other grade of concrete (M30) followed a similar trend. The load-bearing capacity of columns has no significant effect by the increase in aspect ratio from 2 to 4.

Metal friction is a critical phenomenon that affects the performance and longevity of metal components. Understanding the factors that contribute to metal friction and finding effective ways to optimize its results are essential in various industries. To investigate metal friction and optimize results, an experimental design approach is employed. This approach involves systematically varying input parameters to assess their impact on frictional forces. By carefully controlling and manipulating these parameters, researchers can gain insights into the underlying mechanisms and identify strategies to minimize friction. In the test design method, by using the response surface method, a series of tests consisting of primary parameters are designed, and their results are checked and optimized on the amount of friction. This study focuses on investigating the effects of weight, length of the path, and the speed of the pin on wear using a wear-testing device. The results of the optimization process indicate that the optimal condition occurs when the weight is at its minimum value of 318.2 kg, the speed is at its minimum value of 0.9546 m/s and the path length is 2356.7 m. The results indicate an increase in wear with an increase in weight and length of the path. Additionally, Finite element simulation was done to check the results. The results of experimental operation and finite element simulation showed a good agreement.

Conventional energy sources like fossil fuels are no longer viable due to their limitations and environmental impact. The demand for cleaner, more efficient energy solutions has led to the development of electric machines with smaller volumes and higher output. The family of permanent magnet Vernier motors have high torque output at very low speeds while being very small in volume. In conventional SVPM, the core losses are high, which leads to heating and reducing the efficiency of the motor, and the power factor of the motor is also low, and the torque can increase in relation to the motor volume. The reluctance torque theory, along with the normal output torque of the motor, increases the final torque of the motor. In addition, the toothing of the rotor reduces the cross-sectional area and weight of the rotor. With the reduction of the cross-sectional area, the eddy currents in the core are reduced, the power factor increases and the efficiency of the motor improves. Therefore, in this paper, a spoke-type permanent magnet Vernier motor with a rotor similar to the reluctance rotor has been designed, which has higher torque, lower losses, and higher power factor compared to conventional spoke-type permanent magnet Vernier motors.

In this article, the equations governing the constant ferromagnetic current are investigated. The Lorentz force restrains this ferrofluid flow in a semi-porous valve. Analyzes were performed on three sub-particle fluids: kerosene and blood, water and magnetite. Modeling in the Cartesian coordinate system using the relevant equations was investigated. A slight thinning should be considered in the lower part of this channel. This research has used two Akbari-Ganji methods (AGM) and finite element method (FEM) to solve the equations. Nonlinear differential equations are solved using the above two methods. In the finite element model, the effect of changing the Hartmann number and the Reynolds number on the flow velocity and the derivatives of the velocity and shear stress of the fluid were investigated. As the Hartmann number increases, the velocity decreases in both directions. The Reynolds number changes in different slip parameters, which shows the opposite behavior for the two directions. Also, the insignificant effect of volume fraction of nanoparticles on velocity and its derivatives and shear stress was investigated. The results of solving the equations with the above two methods were compared with HAM. The results obtained using AGM and FEM and their comparison with previous researches have led to complete agreement, which shows the efficiency of the techniques used in this research.

This study presents novel research on the seismic behavior of self-centering reduced beam section (RBS) connections in steel structures. Unlike traditional moment steel frames that concentrate non-elastic deformations in energy dissipation devices, the innovative self-centering RBS connections utilize post-tensioning techniques to restore the structure to its pre-earthquake condition. By significantly reducing residual deformations, these connections offer a promising alternative for improving seismic resilience. To validate the effectiveness of the post-tensioned (PT) and RBS connections, advanced nonlinear numerical modeling using the Finite Element Method (FEM) in ABAQUS software is employed. This approach allows for a comprehensive investigation, comparing the numerical results with laboratory data. Furthermore, the study goes beyond existing research by incorporating additional high-strength cables into the RBS connections. This novel configuration aims to assess the impact of post-tensioned cables on seismic behavior, adding a new dimension to the understanding of these connections. Through a rigorous parametric study, the research uncovers crucial insights into the seismic performance of the self-centering RBS connections. Notably, the study reveals the significant influence of the initial post-tensioning force on various aspects, including stiffness, maximum moment capacity, and gap-opening behavior of PT connections. The findings demonstrate the potential of increasing the initial post-tensioning force to enhance the energy dissipation capacity and overall performance of the PT connections. Overall, this study presents pioneering research that advances the understanding of self-centering RBS connections and their potential application in steel structures. By emphasizing the novel aspects of the research, it contributes to the body of knowledge in the field and provides valuable insights for improving the seismic resilience of structures.

Cleaning the huge oil storage tanks is very costly, hazardous, and time-consuming. However, this issue is one of the main concerns of the petroleum products storage industry that is performed in different ways. In this paper, an innovative oil storage tank cleaning procedure in which vertical cylindrical tanks are cleaned without entering any labor into the tank and damaging it is introduced. In this method, before filling the tank with petroleum products (i.e., oil), a sack of PVC fabric is located at the bottom of the tank, and as time passes, the heavier particles (sludge) settle on this sack. Finally, when the sack is filled with sludge, through a mechanism, it is, firstly, shifted towards the center of the tank and, secondly, lifted and taken out through the gate that exists on the roof of the tank. Thus, the above-mentioned approach not only reduces the cost of the cleaning operation but also accelerates the speed of the performed operation. To analyze the stress which is imposed on the sack’s fabric by the weight of the sludge, the finite element method has been applied. The highest stress undertaken by the sack was obtained as 7.630 MPa, which, according to the mechanical properties of the investigated fabric, shows an acceptable safety factor of 1.5. In addition, the strength of the tank’s walls against buckling due to the weight of the sack and sludge was investigated.

The subject of this study is to investigate the effects of surface welding on welding residual stress, analyzing temperature fields, and distortion in low carbon steel. This work aims to simulate residual stresses that appeared during the surface welding of the carbon steel plates via finite element analysis using the ABAQUS software. This analysis includes a finite element model for the thermal and mechanical welding simulation. It also includes a material deposit, temperature-dependent material properties, metal plasticity, and elasticity. The welding simulation was considered as a coupled temperature-displacement analysis. The element birth and death technique was employed for the simulation of filler metal deposition. The residual stress distribution, distortion magnitude, and temperature changes in the center weld metal were obtained. The results showed that applying boundary conditions of mechanical led to a decrease in the plastic strain. In addition, the residual stresses and the temperature fields are dependent on several factors, which include the different boundary conditions and the pre-heating temperature.

In this paper, the temperature and concentration of species around a vessel using the reaction and diffusion relations were investigated. The reactions between 3 chemical species, and the relationship between temperature changes and the rate of chemical reactions were studied. The novelty of this paper is the use of different coefficients of material with diffusion constants and also considering the concentration and temperature of materials involved in the reaction with non-heat sources and with heat source modes. So that showed the concentration and heat transfer rate of substances involved in the chemical reactions in the form of two-dimensional and three-dimensional diagrams about their distance from the borders of the vessel. The finite element method is utilized for calculated differential equations. According to the results obtained, when the temperature of the reactants increased more heat is released; the concentration also changed a lot, and its amount increased. However, in products such as substance (c), it has an inverse relationship with reactants (a) and (b) in such a way that as the concentration and temperature of the reactants increased, these values decreased in the product. On average, concentration changes in the distance from the center to the surroundings the maximum heat source mode was about 76% less than the average heat source mode and about 14% less than the non-heat source mode.

This paper presents the design of an Magnetorheological (MR) damper that includes an arrangement of a piston and cylinder. This study developed a 3-D  model based on the finite element method (FEM) concept on the COMSOL  Multiphysics to analyze and investigate the MR damper characteristics. A  prototype of the MR damper is being fabricated based on the FEM model and is put through a series of experiments using the Servo-Hydraulic material testing machine (MTS). Maximum and minimum forces, 171.5235N and 249.2749N, were measured at 0.1Hz and 1Hz, respectively, for the FEM model. The fabricated model obtained similar results at 0.1Hz and 1Hz, with maximum and minimum forces of 175.9103N and 252.7765N, respectively. Comparing these two model analyses reveals that the FEM-based model accurately depicts the experimental behaviour of the MR damper in terms of its damping force, although there is minor variation. The findings of this paper will be helpful for designers in creating MR dampers that are more efficient and reliable, as well as in predicting the characteristics of their damping force.

In recent years, composites have been used to reduce the overall weight of the structure and reduce the consumption of fossil fuels in aircraft due to their light weight property. The purpose of this study is to investigate the interlayer stresses created in composite layers due to the effect of free edges. In fact, in this study, the distribution of stresses affected by free edges (interlayer stresses) that create force and torque in the direction of thickness is investigated. For this purpose, the changes of the mentioned stresses with the help of numerical modeling for multilayer composite by finite element method are investigated by Abacus software and the environmental effects of composite materials are also discussed. Finally, the effect of different layers on this phenomenon in terms of thickness and width of several composite layers under axial tensile load will be investigated. As a result, on one hand the extended usage of green materials like composites can potentially reduce the previous heavy metallic structures which use more fuel and have much more environmental side effects, and on another hand some stress analytical results such as symmetrically distribution of , asymmetrically distribution of  across the width of multilayer and other discoveries for angle-ply and quasi-isotropic multilayers due to the effect of free edge are gained.