List of articles (by subject) optimization and simulation
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Open Access Article
1 - Simulation of Ultrasonic Welding of Al-Cu Dissimilar Metals for Battery Joining
Reza Abdi Behnagh Peyman Esmaeilzadeh Mohsen Agha Mohammad PourUltrasonic welding is gaining popularity for joining of thin and dissimilar materials and foils in the fabrication of automotive Li-ion battery packs because of excellent efficiency, high production rate, high welding quality, etc. Precise control of the parameters of t MoreUltrasonic welding is gaining popularity for joining of thin and dissimilar materials and foils in the fabrication of automotive Li-ion battery packs because of excellent efficiency, high production rate, high welding quality, etc. Precise control of the parameters of the welding process plays an important role in achieving good joint quality. Numerical simulation can greatly help control the main input parameters such as frequency, clamping pressure, friction coefficient, and vibration amplitude. In this present work, a three-dimensional thermo-mechanical Finite Element (FE) model is proposed using ABAQUS/EXPLICIT for the dissimilar Al to Cu weld to predict the deformation and temperature as output parameters during welding process by varying input parameters. The simulation results showed that the clamping pressure, vibration frequency and friction coefficient have a great influence on heat production during the process which was critical to determine the final quality of the welded joint. Studies also showed that increased clamping force and welding frequency led to increased deformation. Manuscript profile -
Open Access Article
2 - Thermal Optimization of an Array of Needle-Shaped using Constructal Theory
Maryam Hoseinzadeh Afshin Ahmadi Nadooshan Morteza BayarehIn the present paper, the constructal theory is employed to determine the optimal configuration of three rows of needle-shaped fins. The heat transfer across the fins is due to laminar forced convection. Second order upwind scheme is used for discretization of the diffu MoreIn the present paper, the constructal theory is employed to determine the optimal configuration of three rows of needle-shaped fins. The heat transfer across the fins is due to laminar forced convection. Second order upwind scheme is used for discretization of the diffusion terms of governing equations. The pressure–velocity coupling is performed using the SIMPLE algorithm. The heat transfer is optimized subject to constant fin volume. The effect of Reynolds number and thermal conductivity on the optimal configuration is investigated. The results obtained from the present simulations are in good agreement with the numerical results. The results show that pin–fins flow structure leads to the best performance when the pin–fin diameters and heights are non-uniform. At Re = 100 and 200, the optimal value of is 1.3. It is revealed that at Re = 50, the optimal value for is approximately 1.1. The results demonstrate that heat transfer rate is an increasing function of the Reynolds number. Manuscript profile -
Open Access Article
3 - Pareto Optimum Design of Heat Exchangers based on the Imperialist Competitive Algorithm: A Case Study
Mohammadjavad Mahmoodabadi Soodeh ZarnegarIn this paper, the multi-objective optimum design of shell and tube heat exchangers is investigated. A thermal modelling of an industrial shell and tube heat exchanger is performed using an -NTU method for estimating the shell side heat transfer coefficient and pressure MoreIn this paper, the multi-objective optimum design of shell and tube heat exchangers is investigated. A thermal modelling of an industrial shell and tube heat exchanger is performed using an -NTU method for estimating the shell side heat transfer coefficient and pressure drop. The efficiency and total cost (includes the capital investment for the equipment and operating cost) are two important parameters in the design of heat exchangers. The fixed parameters and the ranges of the design variables are obtained from a shell and tube recovery heat exchanger in Barez tire production factory located in Kerman city, Iran. The Imperialist Competitive Algorithm (ICA) is used to find the optimal design parameters to achieve the maximum thermal efficiency and minimum consumption cost as the objective functions. The tube inside and outside diameters, tube length and the number of tubes are considered as four design variables. Furthermore, the effects of changing the values of the design variable on the objective functions are independently investigated. At the end, the obtained Pareto front and the related design variables and their corresponding objective functions are presented. Manuscript profile -
Open Access Article
4 - Optimum Design and Construction of Hydraulic Sections of Parabolic Water Transmitting Channels using the Harris Hawks Optimization Algorithm
Mehrzad torkzadeh Hamed Reza Zarif Sanayei reza kamgarChannels have various types of cross-sectional shapes, including trapezoidal, rectangular, semi-circular, parabolic, chain-curved, semi-cubic parabolic, egg-shaped, and circular as the most common shapes. A channel designer has many design options in different condition MoreChannels have various types of cross-sectional shapes, including trapezoidal, rectangular, semi-circular, parabolic, chain-curved, semi-cubic parabolic, egg-shaped, and circular as the most common shapes. A channel designer has many design options in different conditions, including hydraulic, economic, and hydrological conditions, leakage, etc. Among the above-mentioned sections, the first two have a horizontal bottom while the other sections are curve-shaped with bottom curvature. The primary goal in the design of hydraulic channels is to achieve the maximum flow capacity considering the minimum channel construction cost. A variety of studies has been conducted on the different types of hydraulic channels so far, each dealing with the subject from a certain perspective. However, most of the studies have focused on circular, rectangular and trapezoidal channels. This study has focused on the parabolic channel. Genetic algorithm (GA) and particle swarm optimization (PSO) or GRG algorithms and their combination are usually used for optimization. However, this research adopts a novel and updated meta-heuristic algorithm, namely the Harris Hawks Optimization (HHO) algorithm, to optimize the parabolic channel with a fixed roughness coefficient and determine the optimal dimensions of the channel with different flow rates. This channel uses different flow rates, namely 50, 100, 150, 200, 250, and 300 m3/s to solve the optimization problem. Finally, it was found that the lowest construction cost and the highest efficiency for water supply is achieved with a roughness coefficient of 0.015 and a flow rate of 100 m3/s. Manuscript profile -
Open Access Article
5 - Modelling of Friction Stir Extrusion using Artificial Neural Network (ANN)
Mohammad Ali Ansari Reza Abdi Behnagh Dong Lin Sarang KazeminiaIn the present study, an artificial neural network (ANN) model is developed to predict the correlation between the friction stir extrusion (FSE) parameters and the recycled wires’ average grain sizes. FSE is a solid–state synthesis technique, in which machin MoreIn the present study, an artificial neural network (ANN) model is developed to predict the correlation between the friction stir extrusion (FSE) parameters and the recycled wires’ average grain sizes. FSE is a solid–state synthesis technique, in which machining chips are firstly loaded into the container, and then a rotating tool with a central hole is plunged into the chips at a selected rotational speed and feed rate to achieve indirect extrusion. Selecting rotational speed (RS), vertical speed (VS), and extrusion hole size (HS) as the input and average grain size as the output of the system, the 3–6–1 ANN is used to show the correlation between the input and output parameters. Checking the accuracy of the neural network, R squared value and Root–Mean–Square–Error (RMSE) of the developed model (0.94438 and 0.75794, respectively) have shown that there is a good agreement between experimental and predicted results. A sensitivity analysis has been conducted on the ANN model to determine the impact of each input parameter on the average grain size. The results showed that the rotational speed has more effect on average grain size during the FSE process in comparison to other input parameters. Manuscript profile -
Open Access Article
6 - Application of Topology Optimization in Design of Stem Profile in Hip Implants Using Finite Element Method
Mohammad Reza Niroomand Farzad BoroomandAppropriate design of stem shape is an important factor in total hip replacement. It affects the attachment of the implant to the bone and the stability of the implant. Using topology optimization, this study has been an attempt to propose an optimized model of the stem MoreAppropriate design of stem shape is an important factor in total hip replacement. It affects the attachment of the implant to the bone and the stability of the implant. Using topology optimization, this study has been an attempt to propose an optimized model of the stem profile of the hip implants. In this regard, a three-dimensional finite element model of the implant has been combined with a stiffness-based topology optimization algorithm to reduce the relative motion between the implant and the bone. The objective function in the optimization problem is the compliance of the structure which should be minimized. Also, a constraint on usable volume is applied to the structure. Then smoothing process has been done on the optimal model to prevent its geometric complexities. Results show that the final model has a smaller weight, less displacement, and more uniform stress distribution. In addition, using conventional production methods, this model can be easily produced. Manuscript profile -
Open Access Article
7 - Optimal Process Parameters in ECMAP of Al−3% Mg Alloy Strips
Peyman Mashhadi KeshtibanEqual channel angular pressing (ECAP) is one of the most appealing severe plastic deformation (SPD) methods. The proposed equal channel multi angular pressing (ECMAP) process enhances the efficiency of traditional ECAP technique with decreasing the process time. In this MoreEqual channel angular pressing (ECAP) is one of the most appealing severe plastic deformation (SPD) methods. The proposed equal channel multi angular pressing (ECMAP) process enhances the efficiency of traditional ECAP technique with decreasing the process time. In this study, a complete investigation was done by the design of experiment (DOE) by compound Taguchi-Grey technique. FEM was applied by ABAQUS software in order to achieve responses of proposed Taguchi tests. Die geometrical parameters together with an important process parameter were selected as input factors and strain characteristics and also, required process load were selected as responses. The relationships between responses and input factors were obtained by regression analysis. Then, an analysis of variance (ANOVA) was used to determine the influence of each input factor on responses. ANOVA analysis revealed that FC with contribution percentage of 87.21% has the most influential factor on RPL. Furthermore, it was inferred that among input factors, with contribution percentage of 94.57% has the most effect on the PEEQ. Finally, a multi objective optimization study was done by grey relational analysis. It was concluded that among all input factors, die channel angle, friction coefficient (FC), and die corner angle with contribution percentages of 42.30%, 26.08% and 14.84% are the first, second and third most influential factors on objectives, respectively. Manuscript profile -
Open Access Article
8 - Numerical Study of Non-Gray Radiative Heat Transfer in a T-shaped Furnace
Amin Al Taha MohamadMehdi KeshtkarRadiative heat transfer has an important role in many industrial equipment; i.e. furnaces, boilers and high temperature heat exchangers. In this paper, combination of Weighted Sum of Gray Gas Method (WSSGM) and Discrete Ordinate Method (DOM) are used together in order t MoreRadiative heat transfer has an important role in many industrial equipment; i.e. furnaces, boilers and high temperature heat exchangers. In this paper, combination of Weighted Sum of Gray Gas Method (WSSGM) and Discrete Ordinate Method (DOM) are used together in order to numerically study the radiative heat transfer behavior in a non-gray participating medium. Moreover, the concept of Blocked-off region for irregular geometries is used to simulate the T-shaped furnace. The effect of different radiative parameters, i.e. scattering coefficient and wall emissivity on thermal behavior and wall heat fluxes is investigated and compared for both gray and non-gray media. The results show thatwhen scattering coefficient increases, more radiation is scattered in the medium and therefore less heat flux reaches the walls such that by increasing scattering coefficient from 1.0 to 5.0, the incident radiative heat flux decreases up to 15% in some parts of bottom wall. It is seen that by increasing wall emissivity from 0.5 to 1.0, wall heat flux increases more than 60%. Moreover, results show that, by increasing the temperature, the maximum error strongly increases which indicates that in many engineering problems, the gray medium assumption leads to great error in results. Manuscript profile -
Open Access Article
9 - A New Optimal Method for Calculating the Null Space of a Robot using NOC Algorithm; Application on Parallel 3PRS Robot
Hami Tourajizadeh oveas gholamiIn this paper, a new optimal method for modelling of a 3PRS robot is proposed according to NOC algorithm. An optimal method of selecting the generalized coordinate is presented and a new algorithm of extracting the null space of over and under constrained robots is prop MoreIn this paper, a new optimal method for modelling of a 3PRS robot is proposed according to NOC algorithm. An optimal method of selecting the generalized coordinate is presented and a new algorithm of extracting the null space of over and under constrained robots is proposed through which a lower amount of mathematical calculations is required. In this method, using the principal of derivatives of implicit functions, the null space of constraint matrix will be extracted. Afterwards the null space matrix is calculated with orthogonal columns. The proposed method is implemented on a 3PRS robot which is an under constrained robot. This robot is a kind of parallel spatial robot with 6 DOFs which can be controlled using 3 active prismatic joints and 3 passive rotary ones. This robot similar to other parallel robots has heavy, complicated and nonlinear model which needs heavy and time consuming mathematical calculations. The proposed strategy of extracting the null space of the robot, extremely and heavily decreases the volume of required mathematical calculations for modelling the robot and consequently decreases the inevitable consumed time of processing and numerical errors and increases the accuracy of simulations. Manuscript profile -
Open Access Article
10 - The Numerical Modeling to Study the Multi-Pass Friction Stir Processing on Magnesium Casting Alloy AZ91
hoda agha amini fashami Mohammad Hoseinpour Gollo Nasrollah Bani Mostafa Arab Bahram NamiIn this research, the multi-pass friction stir processing on AZ91 alloy has been simulated with the three-dimensional numerical modeling based on the ABAQUS/ Explicit. This simulation involves the Johnson-Cook models for defining the material behavior during this intens MoreIn this research, the multi-pass friction stir processing on AZ91 alloy has been simulated with the three-dimensional numerical modeling based on the ABAQUS/ Explicit. This simulation involves the Johnson-Cook models for defining the material behavior during this intense plastic deformation and investing the fracture criterion. Friction stir processing is a complex process that includes several issues such as high strain rate deformation, microstructure evolution, the asymmetric flow of material, and heat. Therefore, the modeling of this process is challenging. This model simulates the tool plunging and stirring phases in the two-pass process. In this paper, to prevent too much damage in the elements during processing, the Arbitrary Lagrangian-Eulerian technique for automatically remeshing of distorted elements has been used. This work shows that the numerical modeling can be an efficient method to study the effect of process parameters on the thermal evolution and the stress distribution. The thermal model was calibrated using the experimental results from the previous works. This model can predict the transient temperature distribution and residual stress field during FSP on AZ91. The results show that the maximum temperature in the advancing side is more than that in the retreating side. In addition, numerical results show that at the end-position of the process, the tool during the lift-up leaves the keyhole region in a compressive stress state. Manuscript profile -
Open Access Article
11 - Multi-objective Optimization of Volute Springs using an Improved NSGA II
navid moshtaghi yazdaniDue to the variable stiffness through their length, their resistance against buckling, damping characteristics due to the friction between their chains, and their small solid length, volute springs are widely used in applications where other mechanisms cannot be employe MoreDue to the variable stiffness through their length, their resistance against buckling, damping characteristics due to the friction between their chains, and their small solid length, volute springs are widely used in applications where other mechanisms cannot be employed to provide variable spring stiffness. Meanwhile, the complexities of equations, governing their dramatic non-linear behavior caused the designers to use experimental equations, as well as some simplifications. Therefore, no research has been reported yet that aims to simultaneously optimize the evaluation criteria of these springs (i.e. their weight and energy conservation capacity) considering their strength, stiffness and natural frequency. In this article providing the governing equations for mechanical behaviors of volute springs, the problem of optimized design for this type of springs are addressed as an optimization problem with its constraints, taking into account the aforementioned goals and considerations. To find a set of Pareto front, an improved version of a multi-objective genetic algorithm is employed, performance of which has been improved, adding a migration operator to a classical NSGA II algorithm. To indicate the proposed method efficiency, a volute spring used in a suspension system of a military motorcar was modeled, and its design was optimized. The results show that the functional performance of the designed volute spring, such as minimizing the spring mass and maximizing the stored energy while maintaining design limitations such as dimensions, strength and critical frequency, has been significantly improved. Manuscript profile -
Open Access Article
12 - Joint Optimization of Spare Parts Strategy and Maintenance Policies for Manufacturing Systems
mohammadali farsi Enrico ZioCost is the most important factor in engineering systems, thus cost reduction and producing components with a reasonable cost are mandatory for manufacturing engineers. Effective maintenance influences the total cost of manufacturing systems, and its efficiency depends MoreCost is the most important factor in engineering systems, thus cost reduction and producing components with a reasonable cost are mandatory for manufacturing engineers. Effective maintenance influences the total cost of manufacturing systems, and its efficiency depends on spare parts management. Therefore, maintenance and spare parts should be jointly managed and significant characters such as ordering, repair and replacement times, shortage, cost, quality, and storage condition of spare parts have to be considered. In this paper, intelligent manufacturing systems with the multi-component structure are considered, that three types of maintenance policies (condition-based maintenance, corrective maintenance, and preventive maintenance) simultaneously support these systems. A joint optimization method based on GA-PS and Monte Carlo simulation is proposed to achieve minimum cost and maximum availability. Also, the influence of spare parts degradation in storage to evaluate system performance is considered. A framework is proposed for this; it can successfully consider the manufacturing machines, maintenance policies and spare parts inventory to obtain the optimal system with the maximum availability and the minimum cost. Also, the results demonstrate that different factors impress the system, and these parameters must be jointly considered. The ordering and replacement times, storing conditions and suppliers' situation are the main factors considered to obtain an optimal system. Manuscript profile -
Open Access Article
13 - Geometric Optimization of APCs anti Explosion Blades using LS-DYNA Finite Element Software
Jalil Jamali alireza rezaieIn this research, several different types of geometries have been compared to prevent the influence of an explosion wave on the glasses of the APCs. This was done using validation and then using LS-DYNA software. Pre and post-processing was done in LS-PrePost software. MoreIn this research, several different types of geometries have been compared to prevent the influence of an explosion wave on the glasses of the APCs. This was done using validation and then using LS-DYNA software. Pre and post-processing was done in LS-PrePost software. So, a mathematical function in this software was used to generate the pressure of the wave on the structure. In order to compare, the displacement parameter was used and the minimum total displacement of the structure as a criterion for optimal performance was considered. Also, two types of cosine curves, two types of polynomial curves (third and fourth order) and a flat blade are investigated. The results showed that for the use of a 150*100 mm2 square flat blade (which is half simulated according to the model's symmetry), the explosion of a wave coming from a distance of 75 mm on the adjacent sheet requires a sheet with a thickness of 11 mm. Using a curved blade, this thickness is reduced to 3 mm. According to the recent issue, the use of curved blades will lead to a sharp decrease in the weight of armored equipment. Manuscript profile -
Open Access Article
14 - The Effect of Process Parameters and Tool Geometrical Parameters on the Tool Peak Temperature in Machining Process
Maziar Mahdipour Jalilian Amir Ghiasvand Hasan KheradmandanIn the present study, the effects of process and geometrical parameters on the maximum temperature of tool have been investigated. Simulation of mild steel machining process in different cutting depths, speed of rotation (SOR), feeding rates, and different rake angles w MoreIn the present study, the effects of process and geometrical parameters on the maximum temperature of tool have been investigated. Simulation of mild steel machining process in different cutting depths, speed of rotation (SOR), feeding rates, and different rake angles was performed. To verify the simulation, numerical results were compared with experimental results. Based on the results, it was found that by increasing the speed of rotation at a constant cutting depth and a constant feed rate, the maximum temperature of the process experiences a significant increase. By increasing the depth of the cut, the geometric location of the workpiece maximum temperature was transmitted to the edge of the tool and surface changes occurred, which it was accompanied with increment in the depth of the cut. The tool with the rake angle of -10° and the depth of cutting of 2 mm had the highest recorded temperature due to the lack of sufficient space for removing chips from the work surface. Manuscript profile -
Open Access Article
15 - FA-ABC: A Novel Combination of Firefly Optimization Algorithm and Artificial Bee Colony for Mathematical Test Functions and Real-World Problems
Ali reza Shafiee sarvestany Mohammadjavad MahmoodabadiIn this research study, an attempt is made to present a new optimization scheme by combination of the firefly algorithm and artificial bee colony (FA-ABC) to solve mathematical test functions and real-world problems as best as possible. In this regard, the main operator MoreIn this research study, an attempt is made to present a new optimization scheme by combination of the firefly algorithm and artificial bee colony (FA-ABC) to solve mathematical test functions and real-world problems as best as possible. In this regard, the main operators of the two meta-heuristic algorithms are employed and combined to utilize both advantages. The results are compared with those of five prominent well-known approaches on sixteen benchmark functions. Moreover, thermodynamic, economic and environmental modeling of a thermal power plant known as the CGAM problem is represented. The proposed FA-ABC algorithm is used to reduce the total cost and increase the efficiency of the system as shown in the Pareto front diagrams. Manuscript profile -
Open Access Article
16 - An Online Trajectory Tracking Control of a Double Flexible Joint Manipulator Robot by Considering the Parametric and Non-Parametric Uncertainty
Alireza Pezhman Javad Rezapour Mohammadjavad MahmoodabadiAccurate trajectory tracking and control of the Double Flexible Joint Manipulator lead to design a controller with complex features. In this paper, we study two significant strategies based on improving the structure of the hybrid controller and training the controller MoreAccurate trajectory tracking and control of the Double Flexible Joint Manipulator lead to design a controller with complex features. In this paper, we study two significant strategies based on improving the structure of the hybrid controller and training the controller parameters for an online estimation of time-varying parametric uncertainities. For this purpose, combination of feedback linearization with an adaptive sliding mode control by considering update mechanism is utilized to stabilize the DFJM system. The update mechanism is obtained based on gradient descend method and chain rule of the derivation. Following, in order to eliminate the tedious trial-and-error process of determining the control coefficients, an evolutionary algorithm (NSGA-II) is used to extract the optimal parameters by minimizing the tracking error and control input. In the second step, an online estimation of the designed parameters were proposed based on three intelligent methods; weighting function, Adaptive Neural Network Function Fitting (ANNF), and adaptive Neuro-fuzzy inference system (ANFIS-PSO). The proposed controller reliability finally was examined in condition of the mass and the length of the robot arm was changed and sudden disturbances were imposed at the moment of equilibrium position, simultanously. The results of the tracking error and control input of the trained proposed controller demonstrated minimal energy consumption and shorter stability time in condition that the control parameters are constant and training are not considered. Manuscript profile -
Open Access Article
17 - Design and Optimization of Gasketed-Plate Heat Exchanger using Bees Algorithm
Navid Bozorgan Ashkan Ghafouri Ehsanolah Assareh Seyed Mohammad Safieddin ArdebiliIn the present study, the hydraulic-thermal design and optimization of a gasketed-plate heat exchanger (GPHE) with an objective function of heat exchanger performance index (the amount of transferred heat exchange to pumping power ratio) is carried out. This process is MoreIn the present study, the hydraulic-thermal design and optimization of a gasketed-plate heat exchanger (GPHE) with an objective function of heat exchanger performance index (the amount of transferred heat exchange to pumping power ratio) is carried out. This process is made by considering 6 design parameters (the port diameter, plate thickness, the enlargement factor, the compressed plate pack length, the horizontal port distance, and the vertical port distance) and through the Bees Algorithm (BA). The present study achieved three solution sets for the design parameters by investigating the sensitivity of the design parameters heeded in the optimization of the GPHE. The design parameters in these three optimal solution sets were opted for in such a way that heat transfer increased by 41.6%, 34.55%, and 20.7%, and pressure drop decreased by 11.89%, 27%, and 83%, respectively. Manuscript profile -
Open Access Article
18 - Simulation and Dynamic-Thermal Analysis of Ceramic Disc and Brake Pad for Optimization by Finite Element Method
Navvab Gholami Ahmad Afsari Seyed Mohammad Reza Nazemosadat Mohammad Javad AfsariThe braking system in cars is directly deals with the issue of safety, and as a result, it is essential to pay attention to this matter. One of the materials used to make disc and brake pads in disc brakes is a ceramic material. This research aims to simulate and analyz MoreThe braking system in cars is directly deals with the issue of safety, and as a result, it is essential to pay attention to this matter. One of the materials used to make disc and brake pads in disc brakes is a ceramic material. This research aims to simulate and analyze the dynamic-thermal ceramic brake disc during the braking operation using the finite element method. Currently, the conventional brake disc is used in the Peugeot 206 car (domestic production), which has low efficiency in terms of life, wear, etc. Therefore, in this research, considering the significant production of Peugeot 206 car in the country, the disc and brake pads of this car have been selected, which were first modeled by Catia software, and after transferring the model to Abacus software and defining the types of ceramics and Cast iron was analyzed by finite element method. Compared the results of the Peugeot 206 ceramic brake disc and pad analysis were with the results of the standard (cast iron) discs in this car. The results showed that the maximum von Mises stress in the ceramic disc was 260.7 MPa, while the maximum von Mises stress in the cast iron disc was 293.3 MPa. The amount of heat produced in the ceramic disc during the braking action in 4 seconds was almost 84% less than the cast iron disc in the same period. Also, the results showed that the ceramic disc has a higher safety factor (1.98) than the cast iron disc (1.45). Manuscript profile -
Open Access Article
19 - Redesign and Accuracy Improvement of Disposable Infusion Pumps
sajjad pakzad ahad shah hoseini Hossein Rashid Myab Amirhossein VazirpanahNowadays, disposable injection pumps are widely used in hospitals and home care settings to provide various therapies such as chemotherapy, antimicrobial, analgesic, and anesthetic treatments, as well as for postoperative pain control and chronic pain control. Since the MoreNowadays, disposable injection pumps are widely used in hospitals and home care settings to provide various therapies such as chemotherapy, antimicrobial, analgesic, and anesthetic treatments, as well as for postoperative pain control and chronic pain control. Since the accuracy of the injection is very important in infusion pumps based on the flow rate, it is therefore important to reduce the error in this device. In this study, the basic design principles of these pumps and the design problems of the sample appearance available in the market were investigated. Since one of the vital problems of this type of pump is their inaccuracy, because they are unable to inject a certain amount of drug for a certain period of time, so one of the main objectives of this study is to improve the accuracy of the injection. Also, as this device is available to the patient for a long time at the time of injection, ease of use is one of the design goals. Finally, this paper ends with a design and prototype which is better in the shape of the device and a big improvement in the accuracy. Manuscript profile -
Open Access Article
20 - Improving High Cycle Fatigue Life in A Gasoline Engine Piston using Oil Gallery with Considering Stress Gradient
Hojjat AshouriFatigue due to thermo-mechanical stresses plays an effective role in causing damage and reducing piston fatigue life. The effect of oil gallery on the thermal stress and High Cycle Fatigue (HCF) life in a gasoline engine piston using oil gallery with considering stress MoreFatigue due to thermo-mechanical stresses plays an effective role in causing damage and reducing piston fatigue life. The effect of oil gallery on the thermal stress and High Cycle Fatigue (HCF) life in a gasoline engine piston using oil gallery with considering stress gradient was investigated. For this purpose, coupled thermo-mechanical analysis of a gasoline engine piston was carried out. Then HCF life of the component was predicted using a standard stress-life analysis and results were compared to the original piston. The results of Finite Element Analysis (FEA) indicated that the stress and number of cycles to failure have the most critical values at the upper portion of piston pin. The obtained thermo-mechanical analysis results proved that the oil gallery reduces the stress distribution in the piston about 7MPa and 12MPa at engine speed 1000rpm and 5000rpm, respectively. The results of high cycle fatigue life showed that the number of cycles of failure for modified piston is approximately 33% and 37% higher than original piston at 1000rpm and 5000rpm, respectively. To evaluate properly of results, stress analysis and high cycle fatigue results is compared with real sample of damaged piston and it has been shown that critical identified areas, match well with areas of failure in the real sample. Manuscript profile -
Open Access Article
21 - Improving High Cycle Fatigue Life in An Exhaust Manifold Using Perimeter Fins with Considering Stress Gradient
Hojjat AshouriThe effect of perimeter fins on the thermal stress and High Cycle Fatigue (HCF) life in an exhaust manifold with considering stress gradient was investigated. For this purpose, coupled thermo-mechanical analysis of an exhaust manifold was carried out. Then HCF life of t MoreThe effect of perimeter fins on the thermal stress and High Cycle Fatigue (HCF) life in an exhaust manifold with considering stress gradient was investigated. For this purpose, coupled thermo-mechanical analysis of an exhaust manifold was carried out. Then HCF life of the component was predicted using a standard stress-life analysis and results were compared to the original exhaust manifold. Mechanical properties of exhaust manifold material were obtained by tensile tests at different temperature. The results of the thermo-mechanical analysis proved that the maximum temperature and stress are visible in the confluence region. The obtained Finite Element Analysis (FEA) proved the fact that perimeter fins reduce the temperature distribution in the exhaust manifolds about 31°C. As a result, the exhaust manifolds tolerate lower temperature and fatigue life will increase. The results of FEA indicated that the stress in the modified exhaust manifolds decreased approximately 19MPa for the sake of depletion of temperature gradient, which can lead to higher fatigue lifetime. The results of HCF showed that the number of cycles of failure for modified exhaust manifold is approximately 63% higher than the results obtained from the original exhaust manifolds. The results of the FEA analysis are compared with the real sample of the cracked exhaust manifold to properly evaluate the results, and it has been shown that critical identified areas correspond to the failure areas of the real sample. Manuscript profile -
Open Access Article
22 - Simulation of a Freight Train and The Effect of Wheel Flat Defect on The Wheel/Rail Dynamic Forces
Sajjad Sattari Mohammad Saadat Sayed Hasan Mirtalaie Mehdi Salehi Ali SoleimaniWheel/rail interaction is one of the most important research topics in railway engineering and generally includes impact response, vibrations, and track safety. Track structure failures caused by wheel/rail impact dynamic forces can lead to significant economic loss thr MoreWheel/rail interaction is one of the most important research topics in railway engineering and generally includes impact response, vibrations, and track safety. Track structure failures caused by wheel/rail impact dynamic forces can lead to significant economic loss through damage to rails, ballast, fastening system, etc. Wheel/rail impact forces occur due to defects in wheels and/or rails such as wheel flats, irregular wheel profiles, rail corrugation, etc. A wheel flat can cause a large dynamic impact force as well as high frequency forced vibrations, which will eventually lead to damage to the train and track structure. In the present work, a freight train (3D model) was used to analyze the dynamic impact caused by the wheel flat using UM software. The effects of wheel flat depth and length (0, 0.2, 0.5, 1, 1.5, 2, and 3 mm) at two speeds of 50 and 80 km/h on wheel/rail dynamic forces have been investigated. The results showed that the presence of a wheel flat defect significantly increases the wheel/rail dynamic impact. For example, by increasing the wheel flat depth to 3 mm, the values of maximum force at speeds of 50 and 80 km/h have changed by about 235% and 400%, respectively. Manuscript profile