Keywords : Finite element method
Numerical Analysis of Linear Elevator Structure Using Finite Element Method
Engineering and Technology Journal,
2021, Volume 39, Issue 9, Pages 1430-1436
DOI:
10.30684/etj.v39i9.2083
In this work, the structure of the linear elevator prototype had been investigated numerically using finite element method. The linear motor structure parameters analyzed using Maxwell ANSYS. The time-stepping method depending on Maxwell equations be applied for analyzing and optimizing the magnetic and force characteristics. While the elevator structure parameters were analyzed using ANSYS workbench based on the principle of virtual work. The frame considered as clamped- clamped beam, and the base of the car considered as thin plate with small deflection. The analysis done with maximum applied load of 360 N at 1.5 safety factor. The results show the distribution of the magnetic lines, the flux density values plus the leakage flux inside the slots. The maximum Von-Mises stress and the deformations of the frame and plate at maximum load are acceptable and present save design. In which the maximum deflection of the thin plate not exceed (thickness/5) at maximum design load.
Design and Performance Analysis of Permanent Magnet Synchronous Motor for Electric Vehicles Application
Engineering and Technology Journal,
2021, Volume 39, Issue 3A, Pages 394-406
DOI:
10.30684/etj.v39i3A.1765
In electrical vehicle applications, power density plays a significant role in improving machine performance. The main objective of this paper is to design and analyze the performance of in-wheel outer rotor permanent magnet synchronous motor (PMSM) used in electric vehicles based on a previously designed model. The key challenge is to achieve the best machine performance regarding the highest torque density and lowest torque ripple. This work also aims at reducing the machine cost by using permanent magnet (PM) material, which has less energy density than the PM used in the previously designed model. An optimization procedure is carried out to improve the generated torque, keeping the same aspects of size and volume of the selected machine. On the other hand, the other specifications of the machine are taken into consideration and are maintained within the acceptable level. According to their major impact on the machine’s performance, the most important parameters of machine designing is selected during the optimization procedure. This proposed machine is implemented and tested using the finite element software package “MagNet 7.4.1” with Visual Basic 16.0 programming language and MATLAB 9.5 Simulink for post-processing.
Effect of Orientation and Pre-Tension on Stresses Distribution on V-Die Bending Processes by Finite Element Method
Engineering and Technology Journal,
2020, Volume 38, Issue 5, Pages 636-648
DOI:
10.30684/etj.v38i5A.457
Simulation of metal forming processes using the Finite Element Method (FEM) is a well-established procedure, being nowadays possible to develop alternative approaches, such as inverse methodologies, in solving complex problems. This study investigated the effect of orientation and pre-tension on stresses distribution numerically by software ANSYS 19 using the finite element method. The pre-tension is 55% from total strained in each rolling direction. The results show that the orientation has a significant effect on stresses distribution and stress value before and after pre-tension 55%. Although there is a regular distribution of stresses in three direction, but there is significant difference in the values of stresses in each of (0, 45, 90) degrees. The highest value of t rolling direction. The pre-tension has a greater impact on stresses distribution and stress value. Although, there is a regular distribution of stresses in blank before and after pre-tension, but there is significant difference in the values. Where in 0 degree on rolling direction the stresses increased by 31.7% from their values before pre-tension, while in 45 degrees on rolling direction the stresses increased by 35.6% and in 90 degrees on rolling direction the stresses increased by 23.6% from their values before pre-tension.
Investigation of The Effect of Loading Paths in the Tube Hydroforming Process
Engineering and Technology Journal,
2018, Volume 36, Issue 12A, Pages 1236-1243
DOI:
10.30684/etj.36.12A.4
The control accurately of internal pressure, axial feeding and paths of loading which have important influences on the final tube quality. In this research an impact of loading path of the tube hydroforming process and final part requirements ( i.e. thickness specification and shape conformation) were studied numerically. Small bulge shape tube hydroforming parts were utilized in the finite element analyses to get several guidelines on the effect of the relation between the internal pressure and axial compressive feeding programs. Two dimension model of bulge shape tube (50 mm) bulge width has been developed from cylindrical tube with thickness (2mm) of the copper and (60 mm) outer diameter. A commercial available finite element program code (ANSYS 11), is used to perform the numerical simulation of the tube hydroforming operation. The results demonstrate that, the loading path has very important influenced on the thickness distribution over the tube and capability attained the target shape of the required product.
Experimental and Numerical Study of the Earing Defect During Square Deep Drawing Process
Engineering and Technology Journal,
2018, Volume 36, Issue 12A, Pages 1267-1275
DOI:
10.30684/etj.36.12A.8
Deep drawing process is a very complex process which controls a lot of parameters and the associated defects. The aims of this research are to discuss the effect of parameters of the process utilized in square deep drawing process such ; material properties, blank size, blank shape on the height and shape of earing defect appear of the drawn cup. Three dimensions model from low carbon steel (AISI 1008) with thickness 0.7mm of square cup (41.4mm by 41.4mm). The finite element software (ANSYS 11) was utilized to carry out the numerical simulation of the deep drawing process, and the experimental work result of earing was compared with numerical of earing shape result. In this work, three types of the radius of die entry of 3, 5, 7mm, three shapes of the blank (circular, octagonal, and square) with various diameters, four types of radius of the punch profile of 3, 5, 6, and 7mm had been selected to form a cup with square sides. The results show that, The circular blank give the best results according to earing defect and useful height of the drawn cup, when square shape of blanks were utilized, excessive earing will show in the square cup, due to non-uniform distribution of blank material around the perimeter of the die cavity, minimum material in the flat side and too much material found in the die corner, while when using octagonal shape of blanks which have a same surface area to the square blank, the earing will reduce in the corner of the cup due to extract of the too much material from the blank corners. The results showed a high agreement between the experimental work and numerical simulation reached to 85 % in terms of the shapes and lengths of the earing appearing in the square cups.
Modeling of Continues Laser Welding for Ti-6Al-4V Alloys Using COMSOL Multiphysics Software
Engineering and Technology Journal,
2018, Volume 36, Issue 8A, Pages 914-918
DOI:
10.30684/etj.36.8A.11
A model for laser welding process using finite element method, the model was used for this work using the COMSOL Multiphysics software to predict the distribution of the temperature in the joint and to show the four welding zones (the melting zone, partial melting zone, zone affected by heat, and the material base). CO2 continues (CW) Laser used in the model welding thin sheets of titanium alloy Ti-6Al-4V. The results of this simulation work have been compared with the experimental works to show good agreement.
Metal Flow Control in Producing the Non Symmetrical Parts in Deep Drawing Process
Engineering and Technology Journal,
2018, Volume 36, Issue 6A, Pages 603-611
DOI:
10.30684/etj.36.6A.2
the quality of the cups drawn in the deep drawing process are secured by the rate of metal flow into the die cavity, efficiently control on the metal flow can reduce and eliminate a lot of defects such as wrinkling, tearing and earing especially in the square deep drawing due to the non-uniform stresses induced along die cavity. This control is obtained using a restraining force supplied by blank holder tool or draw beads or both. Therefore this research focuses on the study these parameters numerically and experimentally. Ansys software based on finite element method was used to model and analyze the influence of blank holder gap and draw bead parameters in the forming process. Appropriate number of the experiments were done to compare and verify the results obtained in the numerical simulation.
Experimental and Numerical Analysis of Piled Raft Foundation Embedded within Partially Saturated Soil
Engineering and Technology Journal,
2017, Volume 35, Issue 2A, Pages 97-105
DOI:
10.30684/etj.35.2A.1
This paper presents an experimental and numerical study to investigate the load carrying capacity of piled raft foundation embedded within partially saturated sandy soil. The effect of matric suction on the bearing capacity of the foundation system was investigated. The experimental work consists of two models of foundation, circular raft foundation and circular piled raft foundation. The circular raft foundation has dimensions of 10cm in diameter, and 2.5cm thickness, while the piled raft foundation has the same dimensions of the circular raft model but with a single pile of 2.0cm in diameter and 40.0cm in length fixed at the center of the raft. Both models are loaded and tested under both fully saturated condition and unsaturated conditions, which are achieved by, predetermined lowering of water table. The lowering of water table below the soil surface was achieved in to two different depths to get different values of matric suction and the relationship between matric suction and depth of ground water table was measured in suction profile set by using three Tensiometers (IRROMETER). The soil water characteristic curve (SWCC) estimated by applying fitting methods through the software (SoilVision). A validation process then was carried out for the case of circular piled raft foundation with lowering the water table 45cm bellow soil surface in the aid of a sufficient finite element computer program ABAQUS 6.12. An eight-node axisymmetric quadrilateral element CAX8RP and CAX8R were used to simulate the soil continuum and piled raft respectively. The interaction method used to simulate the intersect surfaces of the system (pile-raft-soil) is a surface-to-surface discretization method under the concept of master and slave theory. The behavior of piled raft material is simulated by using a linear elastic model while the behavior of soil is simulated by an elasto-plastic model by the use of the Mohr-Coulomb failure criterion. The results of the experimental work demonstrate that the matric suction has a significant role on the bearing capacity of all tested models. It shows that the ultimate bearing capacity of circular raft foundation under a partially saturated condition is increases by about (7.0-8.0) times than the ultimate bearing capacity of fully saturated condition when lowering the water table 45 cm below the soil surface. While the ultimate bearing of circular piled raft foundation under partially saturated condition increases by about (8.0-9.0) times than the ultimate bearing capacity of fully saturated condition when lowering the water table 45 cm below the soil surface. The results of the ultimate bearing capacity of piled raft foundation that obtained from the experimental model and from the numerical modelling for the same soil condition and same matric suction indicate that a successful validation is achieved for the simulation process.
Thermal Lensing Reduction in Conventional and Composite Nd:YAG Laser Rod
Engineering and Technology Journal,
2016, Volume 34, Issue 11, Pages 2031-2035
DOI:
10.30684/etj.34.11A.9
A finite-element method (FEM) wasused to simulate numerically the effect of thermal lensing in YAG rods doped with Nd ion using LASCAD software. The temperature distribution and thermal lensing focal length of the composite laser rod (YAG/Nd:YAG) with one undoped end cap was considered and compared with conventional laser rod (Nd:YAG) by applying software. Results show that thermal lensing effects were reduced by a factor of 2 using (YAG/Nd:YAG) composite rod at pump power of 20W.
Numerical Analysis of The Multi-Stage Reverse Deep Drawing Process
Engineering and Technology Journal,
2016, Volume 34, Issue 3, Pages 613-622
DOI:
10.30684/etj.34.3A.15
The paper presents an analysis of the multistage deep drawing process considering the three deformation stages namely drawing reverse and reverse redrawingrespectively. This work aim to study the mechanism of deformation during the redrawing process where the second and the third stages were done in reverse redrawing and study the effect of this mechanism on produced cup wall thickness, strain distribution across the wall of the drawn part. 2-D model of cylindrical cup (46.75mm) diameter has been developed in the first stage from sheet with thickness (0.5mm) of the low carbon steel (AISI 1008) and (85mm) diameter, while for second and third stages of drawing a punch diameter (32.725mm, 27.489mm) respectively, and inside diameter of dies equal to (33.825mm, 28.589mm) respectively, the clearance is chosen for three stage equal to 0.55mm. A commercial available finite element program code (ANSYS 11), is used to perform the numerical simulation of the multistage deep drawing. The results show that, when considering multi-stage drawing, the task is even more difficult because the strain and thickness distribution resulting from the first stage will influence the subsequent results,increase in thinning in the wall cup will appear in the second and third stages. Finally this work introduces new method (multi reverse redrawing) to produce circular cup throw three stages of drawing reduction in one stroke without the need to the loading and unloading the tools among the stages as in direct redrawing which means reducing the cost, time, efforts and enhancing cup production.
Study of the Influence of the Elastic Rubber Cushion on Product Quality Formed by a Multi - Point Forming (MPF) Process
Engineering and Technology Journal,
2016, Volume 34, Issue 3, Pages 452-463
DOI:
10.30684/etj.34.3A.3
The Multi-Point Forming (MPF) is an advanced flexible manufacturing technology for three – dimensional sheet metal forming. This is replacing the conventional solid dies by a set of discrete punches called (punch group).
This work presents the design and manufacturing of (MPF) dies. It covers also, the effect of using an elastic cushion on the quality of products. This technique eliminates the formation of dimples which, otherwise reduces the quality of product. The work falls into two parts. Part one includes the use of ANSYS, which employs a finite element method (FEM) for the simulation of MPF components, namely: upper jaw, lower die and cushion. In the other part (experimental), a complete MPF die was designed and manufactured in the local market.
The copper sheet metal was selected to study the influence of the elastic cushion on the quality of product which formed by MPF process. This rubber was used to avoid the dimples occurring on the metal surface. Experimental and numerical results showedthatthis technique produces a better quality free from dimples. The cushion proved to be effective in elimination of the thickness change. The thickness change was found to be in the range (0-0.05) for a blank of 2 mm.
Hence, it is recommended that the (MPF) method is effective in product quality. However, two layers of cushion are necessary to separate between the workpiece and pins to reduce the work piece deformation. Also, the numerical simulation was used by (ANSYS) software which was compared with the experimental result. A good agreement for numerical and experimental results was found.
Effect of Web Opening on the Ultimate Capacity of Steel Plate Girders under Two Points Load
Engineering and Technology Journal,
2016, Volume 34, Issue 1, Pages 165-177
DOI:
10.30684/etj.34.1A.14
The structural behavior of steel plate girders with web opening is investigated in this study. An experimental and theoretical investigation of plate girders with circle and square openings in the web was conducted. The experimental work included testing of seven plate girder specimens under two point loads. Three specimens were tested to observe the influence of the circular web opening. The influence of the presence of square web openings was studied by testing other three specimens. The last one was tested without opening as a reference (control) specimen. These specimens had the same dimensions. The experimental results showed that the ultimate load capacity of the girders decreases with increasing the opening size, and the position of plastic hinge depends on the size of hole.
Three-dimensional nonlinear finite element analysis has been used to conduct the numerical investigation of the structural behavior of plate girders with web opening. ANSYS (version 12.0) computer program was used in this study. Four- nodes shell element (SHELL 181) was used to represent the steel plate. The proposed finite element model has been used to carry out a parametric study to investigate the effects of two parameters; web slenderness and flange stiffness ratios, on the ultimate load capacity of plate girders with circular web openings.
Experimental and Finite Element Analysis on Rounded Corners Square Shape Tube Hydroforming Process
Engineering and Technology Journal,
2014, Volume 32, Issue 9, Pages 2148-2164
DOI:
10.30684/etj.32.9A4
Tube hydroforming is a forming process where an inner pressure combined with axial feeding deforms the tube to the shape of a die cavity, i.e. the process state where the hardening of the material is unable to resist the increase in inner pressure and wall thickness reduction. In the current work the tube with circular cross section is deformed to square cross section using hydraulic pressure. The die of the square edges is designed and manufacturing to change the tube with circular cross section to square cross section. The die and tools were designed and manufactured in order to satisfy the experimental work.The hydraulic system manufactured is capable to give several values of internal pressure. Initially circular tubes are inflated against a square die while simultaneously they are axially compressed in order to delay wall thinning and burst and achieve an accept tube wall thickness distribution. The dimension of tube used in the experimental work of copper is (L=110 mm, do=9.4 mm , to=1.5mm) to obtain forming limit diagram and mechanical properties of tube and value of the bursting pressure and final thickness for copper tube (170MPa ) and 1.18 mm. A squared grid has been printed by screen method with dimensions (5x5mm) the strain measurement accomplished by measuring the dimensions of the grid printed before and after deformation. The finite element method was applied via ANSYS11software package in order to determine the tube thickness, stress and strain behavior and the internal pressure required to form the square shape tube and the radius of curvature of the tube.It was found that the generated strain during the tube hydroforming process in the square cross – sectional die was less than that in ANSYS software within 20%. The results showed good agreement.
Effect of Stress Level of Surrounding Soil on Bored Pile Capacity in Sand
Engineering and Technology Journal,
2013, Volume 31, Issue 15, Pages 2839-2859
DOI:
10.30684/etj.31.15A.5
This study deals with assessing the effect of stress level on bearing capacity
factor , distribution of shear stresses at soil-pile interface along pile shaft, and
presence of critical depth concept for bored piles axially loaded in compression and
embedded in dense sand. These investigations are made using finite element method
with the employment of a wide range of stresses by using piles with dimensions
starting from laboratory dimensions and goes towards field dimensions with
embedment ratio range from (15-40). The soil and the interface behavior is
modeled using Duncan-Chang hyperbolic soil model with empirical equations
account for reduction of angle of internal friction ø with increasing in stress level.
Bored pile is modeled as a linear elastic material. The results showed a dramatic
decrease in bearing capacity factor as length of pile increase. It was also found
that the embedment ratio has a significant effect in increasing bearing capacity
factor , and the distribution of shear stresses at soil-pile interface is not linear and
does not tend to take a constant value beyond a certain depth of pile nor decreases
after a certain depth along pile shaft. The fallacy of critical depth also noticed and
discussed in this paper.
Method for Shielding the Magnetic Field Generated in a 132/33/11(6.6)KV Baghdad Indoor Distribution Substation
Engineering and Technology Journal,
2012, Volume 30, Issue 15, Pages 2562-2576
DOI:
10.30684/etj.30.15.2
This research introduces the study carried out on one of Baghdad East 132/33/11(6.6) kV distribution substations to mitigate 50Hz magnetic field of indoor distribution substation under normal operation. Shielding was performed at the power sources such as busbars rather than at the affected areas. Three-dimensional finite element method (FEM) is used to calculate the magnetic field density in the space nearby the busbars so as to analyze the shielding effectiveness of an eddy current shield applied to a 132/33/11(6.6)kV substation. It also deals with the influence of shield distance from busbar, thickness and material of shield on the eddy current losses and shielding efficiency applied to 3D finite element model of a particular busbar configuration.
Studying a Buckling Behavior for Edge Cracked Plates Under Compression
Engineering and Technology Journal,
2012, Volume 30, Issue 1, Pages 24-42
DOI:
10.30684/etj.30.1.3
In this work, the buckling behavior for edge cracked plates under
compression loading is studied considering the influence of the crack parameters
(i.e. size, location and orientation), plate aspect ratio and plate boundary
conditions. The problem was solved numerically using finite element method
utilizing ANSYS software version11 .The obtained results show that the crack
parameters as well as plate aspect ratio and plate boundary conditions are
efficient factors on the buckling coefficient and corresponding nodal patterns of
such plates. The useful numerical results for buckling coefficients and
corresponding nodal patterns are displayed in figures. According to the author's
knowledge about the published literature on the buckling field, there is no
specific report on the nodal patterns results of such edge cracked plates.
Influence of the Butt Joint Design of TIG Welding on the Thermal Stresses
Engineering and Technology Journal,
2011, Volume 29, Issue 14, Pages 2841-2858
DOI:
10.30684/etj.29.14.2
The aim of this paper is to demonstrate the influence of the single butt joint design of TIG welding on the thermal stresses for carbon steel type St-37. The butt welding was performed by V angles 30°,45°,60° and 90° and the thermal stresses analysis is based on the local moving heat flux. The numerical model developed by ANSYS12
software based on solving the three dimensional energy equation, considering moving heat source and temperature dependent material properties. Temperature and stresses distributions were obtained function of time. From the results, it is evident that the
joint design has an important role in the welding process, when the edge angle of the welding region gets bigger, the faults get less due to increase of heat flux in the welding region. It can be concluded that the specimen with less than 6mm thickness can be welded without edge angle preparation, due to increase the thermal stresses
when edge angle is evident and higher thermal stresses distribution was at edge angle 60° and lowest thermal stresses distribution was at 90°.
Influence of Metal Type on the Deep Drawing Force by Experimental and Finite Element Method
Engineering and Technology Journal,
2011, Volume 29, Issue 13, Pages 2601-2608
DOI:
10.30684/etj.29.13.2
This paper is aimed to study the effect of material type on the drawing force. Three metals are used (low carbon steel 1008 AISI, Austenitic stainless steel 304 AISI, and pure aluminum 1100), as a sheet with thickness of 0.5mm for each one, and they were cutting as a blank with 80 mm diameter, then drawn in a die with 44mm diameter to produce cup. To predict the deep drawing force by finite element method, Hill's yield criteria is used, which examines the effect of anisotropy. Two dimension axisymmetry model of deep drawing were built and analyzed by ANSYS FEM code. The results show that the drawing force for stainless steel is higher than the other two metals due to the difference in metallurgical structure. The numerical results were compared with the experimental; good agreement was found between finite element and experimental results.
Experimental and Theoretical Study of Square Deep Drawing
Engineering and Technology Journal,
2011, Volume 29, Issue 12, Pages 2456-2467
DOI:
10.30684/ etj.29.12.8
This work aim to study the effect of process parameters used in square deep
drawing operation such as ; die and punch profile radius, blank size, blank shape, on
produced cup wall thickness, strain distribution across the wall of the drawn part,
punch force, earing shape and height of the drawn cup. 3-D model of square cup
(41.4mm by 41.4mm), and 0.7 mm thickness from Low carbon steel (AISI 1008), has
been developed. Because of the symmetry in the specimen geometry, only one fourth
portion of the model was needed to be analyzed using finite element method, a
commercial available finite element program code (ANSYS 11), is used to perform
the numerical simulation of the deep drawing operation, and the numerical results of
earing shape were compared with the experimental work. In this work, three types of
blank shape (circular, square, and octagonal), with different sizes, four types of punch
profile radii of 3, 5, 6, and 7mm and three types of die profile radii of 3, 5, 7mm have
been chosen to form a square cup. The results show that, excessive earing will appear
in the square cup when square blank was used, due to excessive material in the corner
and minimum material in the flat side, and when using octagonal blank which have an
equivalent surface area to the square blank, the earing in the cup corner is reduced
because of extraction of the excessive material from the corner of the blank. The best
results were obtained from the circular blank, according to useful drawing height and
earing.
Numerical and Experimental Investigation of Mechanical and Thermal Buckling Loads of Composite Laminated Plates
Engineering and Technology Journal,
2011, Volume 29, Issue 9, Pages 1830-1844
DOI:
10.30684/etj.29.9.17
In this study, the effect of temperature, aspect ratio, number of layer and
boundary conditions on critical buckling load of composite laminated plate is
investigated experimentally and numerically. Simply-Simply-Free-Free and
Clamp-Clamp-Free-Free boundary conditions, three temperatures (40°C, 60°C and
80°C) and four aspect ratio (1, 1.3, 1.5 and 2) will consider for the experimental
work. The thickness of the plate was changed by increasing the number of layer.
It can be seen that when the temperature changes from 40°C to 80°C the
maximum value of Pcr is about (225 N/mm) at (T = 40°C, a/b = 2 and NL = 4), the
minimum value of Pcr is about (11.70 N/mm) at (T = 80°C, a/b = 1 and NL = 2).
Also, it can be shown that in the case of symmetric cross ply laminate (0o/90o/0o)
when the thermal load increased by about 100 % the buckling load decrease by
about 50 % at aspect ratio equal to 1. Finally, It is shown that the critical buckling
load increases with increasing the aspect ratio at constant temperature, number of
layers and boundary conditions.
Application of GIS for the Evaluation of Electromagnetic Field Effects for Iraqi 132KV Electrical Transmission System
Engineering and Technology Journal,
2011, Volume 29, Issue 9, Pages 1751-1764
DOI:
10.30684/etj.29.9.10
This research endeavors to create the 50Hz electromagnetic field atlas for
populated urban areas in the city of Baghdad (Iraq). For this purpose, the 3-
dimensions numerical model based on finite element method (FEM) with time
harmonic system is used for simulated and modeling electric and magnetic fields
surrounding the 132kV transmission system. The calculated magnetic and electric
field levels are compared to exposure guidelines given by International Commission
on Non-Ionizing Radiation Protection (ICNIRP). To assign the dangers regions in the
city, the properties of the Geographical Information System (GIS) were used. The
GIS map highlighted visually the unsafe zones and facilitate the extraction of the
electric and magnetic field levels of exposure.
Influence of Corrosion Rate on the Double Butt Welding Shapes Design for Low Carbon Steel
Engineering and Technology Journal,
2011, Volume 29, Issue 6, Pages 1094-1106
DOI:
10.30684/ etj.29.6.5
The aim of this paper is to demonstrate the influence of butt welding shapes
on the corrosion rate, microstructure and temperature of carbon steel type
St37.The double butt welding was performed by V angles 15°,30° and 45°. The
finite element analysis via ANSYS software is performed, this analysis includes a
finite element model for the thermal welding simulation. The temperature
distribution was obtained. From the results of the microscopic structure it is
evident that the geometric shape has an important role in the welding process,
when the geometric value of the welding region gets bigger, the faults get less due
to increase of heat quantity in the welding region and the corrosion rate for the
rain water is less than of sea water. The work presents the finite element model for
numerical simulation of welding in carbon steel St37 double butt welding.
Optimum Design of Composite Laminated Plate Using Genetic Algorithm and RSM
Engineering and Technology Journal,
2011, Volume 29, Issue 5, Pages 1002-1020
DOI:
10.30684/ etj.29.5.15
The paper is focused on the application of the response surface method (RSM)
in structural optimization. Applications of the response surface method in the
design of composite laminated plate have been discussed. The response surface
method consists of two stages. In the first stage, the random variables is selected in
order to perform a deterministic computer simulation (finite element solution) in
the sample points. In the second stage, the approximation of the function (which
represent the buckling load) is performed in order to obtain response surfaces
using PDS module included in the ANSYS Program. This response surface is
incorporated into a genetic algorithm (GAs) for optimization of random input
variables to obtain maximum buckling load for composite laminated plate
subjected to both mechanical and thermal loading. GAs are stochastic optimization
algorithms based on natural selection and genetics. In contrast to traditional
gradient-based methods, GAs work on populations of solutions which evolve
typically over hundreds of generations. Four and five different variable
formulations are examined. It was found that for SSSS boundary condition and two
layer laminate the optimum values of buckling load for all thermal loading occur at
q1=33o, q2=59o, t1=1.23 mm and t2= 1.25 mm, also it can observe that the
significant random variable are t1 and t3 (in the case of five independent variables)
since the value of buckling load effected with t1 and t3 more than for t2.
The Estimation of Random Response of a Coupled Cylindrical-Conical Shell System Using Statistical Energy Analysis
Engineering and Technology Journal,
2011, Volume 29, Issue 2, Pages 212-225
DOI:
10.30684/etj.29.2.3
A composite, coupled, thin cylindrical-conical shell system made of polyester
resin reinforced by uniformly distributed, chopped, E-glass is analyzed using
Statistical Energy Analysis. Response displacement estimate of the two
subsystems are obtained due the excitation of the cylinder by a broadband white
noise of constant spectral density function. The paper is an attempt to study the
validity of the SEA hypothesis as applied to coupled built-up structures. This is
carried out by the comparison of response estimates of the coupled system in
different 1/3rd octave frequency bands with those obtained from Finite Element
method. The outcome of this work shows that SEA is a powerful tool for the
vibration analysis of coupled systems at high frequencies when the number of
interacting coupled resonant modes is high. Percentage error obtained from the
comparison of results drops sharply as one goes further in frequency. This paper
recommends that the user of SEA must always be aware of the uncertainty of the
results obtained. The uncertainty may arise from the improper selection of
subsystems, coupling loss factors, and the number of interacting resonant modes
of the coupled system.
Electromagnetic Interference Caused by Iraqi 400kV Transmission Lines on Buried Oil Pipelines
Engineering and Technology Journal,
2010, Volume 28, Issue 24, Pages 6937-6953
DOI:
10.30684/etj.28.24.9
The electromagnetic interference caused by power transmission lines to oil and gas buried pipelines is under investigation for many years. Especially during fault conditions, large currents and voltages are induced on the pipelines that may pose danger to working personnel or may accelerate the corrosion of the pipelin’es metal. In this research, the Joule effect of eddy currents induced in the oil buried
pipelines due to the magnetic fields produced by nearby 400kV transmission lines in the South of Iraq have been computed. A computational model based on 2D finite element approach to calculate the heat generation rate. The influence of different earth resistivities for homogeneous earth model during steady state and
fault conditions is analyzed. A mitigation system using mitigation wires has been simulated to reduce induced eddy current heating effects to the safety limit.
Behavior of High-Rise Steel Building With The Inclusion of Warping
Engineering and Technology Journal,
2010, Volume 28, Issue 22, Pages 6580-6601
DOI:
10.30684/etj.28.22.10
The mathematical procedure in this study covers the calculation of sectorial
properties of the equivalent cross-sectional storey for high-rise building frames. The
formulation is efficiently used to obtain the free vibration analysis of high-rise
buildings which are constructed from several columns, beams, shear walls and
bracing etc. the analysis is based on transformation the complex system to a simple
tall column to represent a cantilevered tall building structure. This is partitioned to
nodes one of which indicates a storey with equivalent cross-sectional properties for
all storeys' elements after calculation of these properties with respect to the shear
center of high-rise building. A thin walled bar finite element with seven degrees of
freedom at each node is assumed. A new formulation of the stiffness and consistent
mass matrices of the thin- walled element is presented in this study. The effect of
cross sectional warping and its properties on the flexural, torsional and axial
properties was investigated, using discrete element approach in idealizing the
structure in high rise building. For the purpose of the present study, it is assumed
that the cross-sectional types under condition are only of thin-walled sections.
Algorithm method was developed which covers the calculation of sectorial
properties of the cross section for floor plan in high-rise building, to study the share
of columns for lateral shear force resistance, and investigate the behavior of different
types of high-rise building with inclusion of warping restraint. The effect of natural
frequency with height of tall buildings, and the mode shape for different crosssectional
plans of high-rise building was studied. To check the efficiency and
accuracy, the mathematical procedure is demonstrated for static and dynamic
examples by comparing the results with those obtained by using software ANSYS
program. A difference of 15% is shown. An eigen value problem is analyzed and
numerical examples are discussed.
Determination of the Stresses Concentration Factor and Cracks Growth in the Buildings by Finite Element Method
Engineering and Technology Journal,
2010, Volume 28, Issue 21, Pages 6347-6365
DOI:
10.30684/etj.28.21.12
The novel analysis of two buildings A and B, by finite element method via ANSYS software and experimentally are presented. The investigation is carried out to show the stresses distribution and the deflections and the cracks propagation in the walls and concrete slabs and beams for the two buildings. In both buildings the investigation included load-deflection curves, stresses and cracks patterns. The stress concentration factor is calculated for two buildings. Results are shown that the factor of concentrated for building A is between (8.4-11.4) for walls contain four windows and (6.1-7.4) for walls contain two doors, while in building B the factor of concentrated is between (13.4-14.1) for walls contain one door, and (13.9-14.6) for walls contain three windows. Also the results indicated that the cracks growth in the sites of high concentrated stresses and the load-deflection curve are approximately linear even with different loads.
2D-Flow Analysis Through Zoned Earth Dam Using Finite Element Approach
Engineering and Technology Journal,
2010, Volume 28, Issue 21, Pages 6315-6324
DOI:
10.30684/etj.28.21.9
This paper presents an application of finite element analysis using
CivilFEM/ANSYS(11) software to predict two dimensional steady state water seepage through an earth dam of two soil zones resting on impervious base. Seepage characteristics (quantity and length of seepage surface) produced at downstream are investigated against permeability coefficient ratio changing of the two soil zones, and based on results of the solution it was found that seepage quantity and velocity downstream are very sensitive to any change of permeability
ratio of the two soil zones forming the dam.
Effect of the Number of Horizontal Construction Joints In Reinforced Concrete Beams
Engineering and Technology Journal,
2010, Volume 28, Issue 19, Pages 5803-5821
DOI:
10.30684/etj.28.19.1
In this paper some results from previous experimental test are adopted
and analyzed using a nonlinear three-dimensional finite element ANSYS
computer program (v.11) to investigate the effect of the presence of
horizontal construction joints (H.C.J.) on the behavior of reinforced
concrete (RC) beams.
Three beams having one, two and three (H.C.J.) that divide the beam into equal
parts, as well as one reference beam without a joint were analyzed. The results
obtained from the finite element analysis show very good agreement with the
results obtained from the previous experimental test. The maximum differences in
ultimate loads were about (8.2-10.4)% for all types of tested beams. The presence
of one, two and three (H.C.J.) in RC beams under flexure gave a decrease in the
value of the cracking load such that Pcr was (97%), (85%) and (80%) of (Bref).
The respective ultimate load capacity Pu was (96%), (89%) and (84%) compared
to (Bref).
Active Magnetic Bearing Design Optimization and Transient-State Analysis Using ANSYS
Engineering and Technology Journal,
2010, Volume 28, Issue 16, Pages 5171-5187
DOI:
10.30684/etj.28.16.4
This paper presents design optimization, and transient-state analysis of
active magnetic bearings (AMB) using the powerful ANSYS software package.
ANSYS software provides the required environment for numerical modeling and
analysis based on the finite element method (FEM). In this paper two programs
are developed in ANSYS, the first for modeling and optimizing the analytically
designed active magnetic bearing, and the second for transient-state analysis of the
FE model to investigate the effects of eddy currents on the considered active
magnetic bearing.
Finite Element Analysis of Single Sided Linear Induction Motor
Engineering and Technology Journal,
2010, Volume 28, Issue 15, Pages 5113-5123
DOI:
10.30684/etj.28.15.19
This paper presents analysis and operation of linear induction motor (LIM) using finite element method (FEM). The solution of magnetic field problem is performed for both two and three dimensional approaches. Magnetic vector potential, flux density, field intensity, induced rotor current, and propulsion force are computed for LIM model studied. The effect of velocity is taken into consideration. The primary winding self and mutual inductances are computed for three dimensional analysis.
Influence of Butt Welding Shapes Design on the Microstructure and Stresses of Low Carbon Steel
Engineering and Technology Journal,
2010, Volume 28, Issue 15, Pages 5036-5047
DOI:
10.30684/etj.28.15.12
The aim of this paper is to demonstrate the influence of butt welding shapes on the microstructure, temperature and equivalent stresses of carbon steel type St- 37.The single butt welding was performed by V angles 15°,30°,45° and U shape. The finite element analysis via ANSYS software is performed , this analysis includes a finite element model for the thermal and mechanical welding simulation. The equivalent stresses and temperature distribution were obtained. From the results of the microscopic structure it is evident that the geometric shape
has an important role in the welding process, when the geometric value of the welding region gets bigger, the faults get less due to increase of heat quantity in the welding region. The work presents the finite element model for numerical simulation of welding stresses in carbon steel St-37 butt welding. The welding simulation was considered as a direct coupled thermo- mechanical analysi.s
Evaluation of Transverse Construction Joints of Reinforced Concrete Beams
Engineering and Technology Journal,
2010, Volume 28, Issue 14, Pages 4750-4773
DOI:
10.30684/etj.28.14.6
Construction joints are stopping places in the process of placing concrete, and they are required because in many structures it is impractical to place concrete in one continuous operation. The amount of concrete that can be placed at one time is governed by batching and mixing capacity and by the strength of the formwork. A good construction joint should provide adequate flexural and shear continuity through the interface. In this study, available experimental tests were analyzed by using a nonlinear three-dimensional finite element ANSYS computer program (v. 9). In addition an interface model was proposed for the transverse construction joints.
Six beams with different transverse construction joints at mid-span as well as to one reference beam without joint are analyzed. The reliability of the model is demonstrated by comparison with the experiment and alternative numerical analysis which shows 5-7% difference.
Effect of Shaft Misalignment on The Stresses Distribution of Spur Gears
Engineering and Technology Journal,
2010, Volume 28, Issue 7, Pages 1321-1339
DOI:
10.30684/etj.28.7.5
Shaft misalignment is considered as one of the common repeated
problems in most rotating machineries , which leads to generate vibrations and
extra dynamic loads on transmitting gears teeth, also leads to non- uniformity in
distribution of applied load along the meshing tooth face by being concentrated on
one side of tooth face. The present work concentrated on the analysis of stresses
generated on transmitting gear tooth, also studied the effect of misalignment angle
on stress distribution and its concentration. This is important for the gear design
and those who works in gear maintenance , because fracture is expected to initiate
and propagate at locations of stress concentration . ANSYS program using finite
element technique had been used, as this program is efficient and accurate tool in
stress analysis, especially for complicated shapes. Gear tooth model had been
analyzed using finite element method in three dimensions. After calculating
transmitted load and dynamic load, misalignment angle had been changed from
(0°,0.2°,0.3°,0.4°,0.5°) then its effect on distribution of applied load had been
calculated. The finite element program (ANSYS) had been executed for cases of
misalignment angle (0°,0.2°,0.3°,0.4°,0.5°). The results showed clearly, that the
stresses distribution and its concentration on tooth changed with misalignment
angle and the equivalent stress is direct proportional with the misalignment angle.
According to the values of generated stresses, the tooth fracture can be predicted
Effect of Dual Reinforcement on Wear Resistance by Aluminum Compacts Reinforce by SiC, Al2O3
Engineering and Technology Journal,
2009, Volume 27, Issue 13, Pages 423-429
DOI:
10.30684/etj.27.13.19
The producing composite materials of dual reinforcement in which the matrix material is aluminum reinforced with two types of ceramic particles : which are Alumina (50μm
Keywords
composite materials; wear test ; Al2O3; SiC: Al
Contact Stresses for Different Gear Design Parameter
Engineering and Technology Journal,
2009, Volume 27, Issue 13, Pages 2274-2300
DOI:
10.30684/etj.27.13.3
Gearing is one of the most critical components in mechanical power transmission
systems. This work investigates the characteristics of an Involute gear system
including contact stresses. Current methods of calculating spur gear (Non-linear
Analysis), contact stress using Hertz’s equation, which were originally derived for
contact between two cylinders. To enable the investigation of contact problems with
Finite Element Method (FEM), the stiffness relationship between the two contacts
areas is usually established through a spring placed between the two contacting areas.
This can be achieved by inserting a contact element placed in between the two areas
where contact occurs. A computer program was built up using (MATLAB 6.5). The
results of the two dimensional FEM analyses from ANSYS are presented. These
stresses are compared with the theoretical values (Hertz’s equations). Both results
agree very well. This indicates that the Finite Element Method(FEM) model is
accurate. The results of contact stress analysis indicates that increasing the geometrical
parameters (Pressure angle, number of teeth and module) lead to improve the tooth
contact stress, with the contact position, because the increasing of the geometrical
parameters will results in an increase of the tooth stiffness which leads to decrease the
tooth contact stress.
FEM-Simulation of Single and Multi Layered Induction Heating Systems
Engineering and Technology Journal,
2009, Volume 27, Issue 13, Pages 2245-2262
DOI:
10.30684/etj.27.13.1
Induction heating system has a number of inherent benefits compared to
traditional heating systems. Many analytical and numerical approaches have been applied to solve the problem of induction heating; efforts are made to introduce new development in computational approaches and utilization of newly developed specialized software packages to improve the methods of analysis and design of induction heating systems. This paper includes the description of the steps used for developing a general and comprehensive program, which works under ANSYS 11.0SP1 package environment. This program can be applied to analyze a wide
range of induction heating applications according to finite element method. Analysis approach is extended to deal with induction heating systems with magnetic material workpieces by introducing the multiregion method. Results of analysis the induction heating systems, by using ANSYS package, include all the electromagnetic and thermal quantities related to the induction heating process. To approve the simulation, used in this work, the results were compared with
published practical measurements, a good agreement was achieved.
Theoretical Analyses of the Dynamic Behaviour of Composite Cantilever Beam Manufactured From E-glass Polyester
Engineering and Technology Journal,
2009, Volume 27, Issue 9, Pages 1833-1846
DOI:
10.30684/etj.27.9.14
In order to have the right combination of manufactured E-glass polyester
composite properties and in service performance, the dynamic behaviour is one of the important properties to evaluate. The dynamic behaviour of E-glass Polyester composite was considered in this study where three laminate types was modelled [0o, ± 45o, 0o/90o ], also the influences of fibre orientations as well as the stacking sequences of the laminate layers on the natural frequencies and resonance under harmonic conditions were investigated. Commercial Finite Element ANSYS® Release 10.0 package analyses were used to simulate the Modaland Harmonic behaviours of composite cantilever beams in the frequency range of 0 to 1000 Hz. The first six modes in this frequency range were extracted and compared in the three laminates. A harmonic simulation was investigated to study its structure response to resonance. The results proved that
the [+45]s laminate had higher torsional modal frequencies due to its higher shear modulus and is more stable under loading than [0/90] laminate due to the arrangement of the layers.
Thermal Effects on Diesel Engine Piston and Piston Compression Rings
Engineering and Technology Journal,
2009, Volume 27, Issue 8, Pages 1444-1454
DOI:
10.30684/etj.27.8.1
This paper introduces an analytical study on the thermal effects on the diesel
engine piston and its compresion rings during the contact between the piston and its
compression rings .A three dimensional finite element model is built for the piston
and its compression rings using the ANSYS v. 8 Finite Element Analysis Code
that serves all engineering problems . The thermal analysis is made using contact
case between the piston and its compression rings .The work in this paper did not
include a convergence study.
The study includes the effects on the piston and piston compression rings
of the thermal conductivity of piston material , and the contact area .The conclusions
of this study are that the material type of high thermal conductivity is considered better
than the material type of low thermal conductivity. This means that the aluminum
alloy is considered better than the cast-iron alloy, and tapering the compression rings
from the inner side by 1 mm , leads to a reduction in the temperature values by
1.6% , 0.84% and 0.37% compared to rectangle compression rings.
Buckling Analysis of Composite Laminated Plate with Cutouts
Engineering and Technology Journal,
2009, Volume 27, Issue 8, Pages 1611-1621
DOI:
10.30684/etj.27.8.15
The determination of critical buckling load of composite plate is an
important factor in determining the structural stability, which was done by ANSYS
program and experimental investigation was carried out on many specimens of
composite material of E-glass fiber reinforced polyester plastic materials with
different no. of layers. Five cases are studied to show the effect of cutout’s
parameter on the structural stability in which the shape ( circle, square, rectangle),
size (20, 30, 50 ) mm, rounding corner (5, 7.5, 10)mm and orientation of cutouts
(0°,30°,45°,60°) are presented . Also the effect of plate thickness (no. of layer) is
studied .
In general , the results of the square clamped laminated plates with circle
cutout come out in a good agreement. Which is decrease of buckling load of the
plates with change the shape from circle, square and rectangle and in case of cutout
size. The critical load is still constant with the radii rounding corner and increased
with increasing the cutout orientation and the thickness of the plate. The effect of
cutout will determine the increase or decrease of the buckling
Nonlinear Finite Element Analysis of Reinforced Concrete Beams with a Small Amount of Web Reinforcement under Shear
Engineering and Technology Journal,
2009, Volume 27, Issue 8, Pages 1485-1496
DOI:
10.30684/etj.27.8.5
This research work presents a nonlinear finite element investigation on the
behavior of reinforced concrete beams with a small amount of web reinforcement under
shear. This investigation is carried out in order to get a better understanding of their
behavior throughout the entire loading history.
The three- dimensional 20-node brick elements are used to model the concrete, while
the reinforcing bars are modeled as axial members embedded within the concrete brick
elements. The compressive behavior of concrete is simulated by an elastic-plastic
work-hardening model followed by a perfectly plastic response, which terminated at
the onset of crushing. In tension, a fixed smeared crack model has been used.
The Effect of Thermal Loadings on the Dynamic Behavior of Cylindrical – Conical Intersection shell
Engineering and Technology Journal,
2009, Volume 27, Issue 4, Pages 831-851
DOI:
10.30684/etj.27.4.19
This paper presented a numerical methods based on FEM were used to study
the effect of temperature on the dynamic characteristic of composite cylindrical
conical shell with different cone angle and wall thickness. The study taken into
account the effect of temperature on the material properties of the selected
material and the effect of pre stressing on the natural frequency of the shell. A
general conclusions could be obtained from the static analysis ,i.e. for higher
circumferential wave number, the effect of increasing the thickness is to produce
higher natural frequencies. The natural frequency of the system may drops by
about (12 %) as a result of the degeneration of the material properties due to
temperature elevation. The higher circumferential wave number, the more
pronounced is the influence of ply orientation on the resulting natural frequency
changing the ply orientation for 0/90/0 to 75/-75/75 may increase the natural
frequency by about (100 %). Finally the transient dynamic stresses may exceeds
the design stress by a bout (50 %).
Behavior of Composite Steel-Concrete Beam Subjected To Negative Bending
Engineering and Technology Journal,
2009, Volume 27, Issue 1, Pages 53-71
DOI:
10.30684/etj.27.1.5
This work deals with the behavior of structural continuous composite steelconcrete
beams, which are widely used in building and bridge constructions. Therefore
the structural behavior of composite beams under negative moment is a significant
subject. However experimental tests in this field are very rare and information about the
efficiency of shear connection when the slab is under tension are really few.
In the present research, available experimental tests on composite steel-concrete
beams under negative bending are theoretically analyzed using the finite element
software ANSYS. ANSYS computer program is a large-scale multipurpose finite
element program which may be used for solving several cases of engineering analyses.
The proposed three dimensional model is able to simulate the overall flexural
behavior of composite beams. This covers; load-deflection behavior, longitudinal slip at
the steel-concrete interface, and distribution of shear studs. The reliability of the model
is demonstrated by comparison with available experiment and alternative numerical
analysis which shows 9-10% difference.