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Finite element analysis and computer-aided engineering methods have an essential role in modern research and development projects. Although proper element selection for the modeling type is critical for the accuracy of simulations, the selection process might be difficult for researchers in some cases where geometric conditions are challenging. The main objective of this paper is to present the differences in simulation results when three-dimensional cubic and two-dimensional quadrilateral elements are used for the modeling of spot-welded components. Following the modeling of shear specimens having two spot welds with different element types, static analysis, and high cycle fatigue simulations at three different dynamic load cases have been run within the context of this study. Displacement, stress values and tensors, as well as high cycle fatigue life have been evaluated as the output of analysis, and deviations due to different element types have been reported. Accuracy levels of different element types have been determined by comparing the life obtained by simulations with high cycle fatigue tests. The studies conducted within the content of this paper indicate that the rigid spot weld modeling with two dimensional quadrilateral elements give better consistency with the fatigue tests in comparison with the modeling with three dimensional cubical elements. The modeling procedures of correlated high cycle fatigue simulations have been detailed for spot welding, which is one of the most applied methods in aviation, automotive and marine industry. [ABSTRACT FROM AUTHOR]

In this paper, in order to determine the laying conditions of power cables used in air vehicles, the thermal behavior, which is one of the dominant factors affecting the current carrying capacity, was investigated by the finite element method. For this purpose, electrical-thermal multiple physical analysis model was created in COMSOL programme to observe the relationship between the temperature of the cable and the environment in which it is laid and the current carrying capacity. In the analysis, 2 AWG (39.19 mm2) cross-section cables in accordance with SAE AS22759/1 standard were taken into consideration. Within the scope of the study, the effect of both the ambient temperature and the distance between the cables on the current carrying capacity of the cable was examined. Considering the maximum temperature value (200℃) that the selected cables can withstand, while there is a distance of 75 mm between the cables it has been observed 198A for a cable. When the distance between the cables is 30 mm and the cables are adjacent, current values are as 184A and 181A, respectively. When the cables are in adjacent, analysis was performed for ambient temperature values of 70℃, 50℃ and 20℃. According to these ambient temperature values, current carrying capacity is calculated as 179A, 191,5A and 205A respectively. As a result of the analysis, the decrease in the distance between the cables causes the current carrying capacity of the cable to decrease and it has been observed that the decrease in the ambient temperature also causes the current carrying capacity of the cable to increase. [ABSTRACT FROM AUTHOR]

This paper investigates the effect of own weight on the dynamic analysis of a pre-stretched composite platestrip containing a circular hole subjected to bending load. The combined effect of body forces (weight) and surface forces (pre-stretching load) on the plate-strip with a hole is considered as the initial stresses determined within the linear theory of elasticity. The effects of these initial stresses on the natural and forced vibrations around the hole within a plate-strip under additional bending load are investigated in the framework of the Three-Dimensional Linearized Theory of Elasticity (TDLTE) under the plane strain state, and the solutions of the considered boundary value problems are solved numerically by using the finite elements method. This paper shows that the influence of the plate's own weight has an important role on the dynamic analysis around the circular hole within a plate-strip. [ABSTRACT FROM AUTHOR]

The paper demonstrates the determination of the fracture parameters of concretes included recycled aggregate (RA) and silica fume (SF) and the crack pattern of a reinforced concrete beam. Double-K fracture model (DKFM) is considered in this paper and the required parameters for DKFM are obtained from the model simulated using finite element method (FEM) in Abaqus. In the simulation parts geometric nonlinearity and material nonlinearity is considered and the parameters of materials for modelling applications depends on the experiments. The fracture parameters are calculated after obtaining the FEM model analyses. The implemented study of fracture behavior of the conventional and recycled aggregate concretes with and without SF and RA reveals that the conventional concrete fracture models (double-K fracture model) could be used to determine the fracture parameters and fracture behavior of RAC and both SF and RA use in concrete has an effect on fracture properties is found. Moreover, crack pattern of a reinforced concrete beam with and without RA and SF is investigated. According to the results, number of cracks decrease but the depth of cracks increase and initial cracking toughness increases if both RA and SF are used at various ratios in the concretes. Although RA inclusion in concretes decreases the rigidity of the beam, approximately equal elastic bearing capacity of the beam is found. [ABSTRACT FROM AUTHOR]

This paper investigates the effect of own weight on the dynamic analysis of a pre-stretched composite plate-strip containing a circular hole subjected to bending load. The combined effect of body forces (weight) and surface forces (pre-stretching load) on the plate-strip with a hole is considered as the initial stresses determined within the linear theory of elasticity. The effects of these initial stresses on the natural and forced vibrations around the hole within a plate-strip under additional bending load are investigated in the framework of the Three-Dimensional Linearized Theory of Elasticity (TDLTE) under the plane strain state, and the solutions of the considered boundary value problems are solved numerically by using the finite elements method. This paper shows that the influence of the plate's own weight has an important role on the dynamic analysis around the circular hole within a plate-strip. [ABSTRACT FROM AUTHOR]

Masonry historical monuments that connecting the past and the present are of major importance in terms of reflecting the knowledge and property of different cultures. This explains that why the protection of historic monuments is so important. The preservation of the historical monuments that constitute our historical and cultural heritage is only possible if they are examined in detail, their problems are solved and their solution methods and techniques are improved. One historical masonry mosque was selected to study in this paper. The mosque is modeled and analyzed by using SAP2000 finite element software in accordance with the dimensions of an architectural building survey. Seismic assessment of the monument was carried out via three-dimensional time-history dynamic analyses of the structure. Minimum and maximum values of displacements, base shear, and stress were interpreted, and the results were displayed graphically and discussed the earthquake motion was applied in two different directions which is X and Y. The seismic capacity of this building has been determined for varied earthquake grade. As a result of the analysis, displacements, stresses (tensile and compressive), base shear force were calculated under the effect of earthquakes. The Structural safety of the mosque was evaluated, and three-dimensional finite element analysis gave a general idea about the structural performance of the mosque. [ABSTRACT FROM AUTHOR]

Most studies on permanent magnet synchronous motors (PMSMs) focus on either interior type or surface mounted magnet configurations and their design changes. This paper deals with the improvements on PMSMs' efficiency and performance after Halbach Array implementation by using meta-heuristic optimization algorithms. Analytical and numerical modeling of the motor are achieved and finite element method (FEM) is used for the numerical models. Particle swarm optimization & genetic algorithm were performed for the optimal design of the geometrical parameters of the permanent magnet (PM). The analytical and numerical results of the proposed design are compared to the analytical and/or numerical results of the reference motor. The improvements in efficiency, power/weight ratio, and cost are achieved with the optimized motor structure for the same motor requirements. [ABSTRACT FROM AUTHOR]

Bird strike is a significant threat to aviation safety. Of all foreign object damages to aircraft, 90 % can be attributed to the bird strikes. Most bird strikes are occurred when an aircraft is at a low altitude during take-off and landing phases of a flight. To ensure flight safety, aviation regulations require a certain level of bird strike resistance for critical components (windward components such as nose, windshield, motor engine inlet, wing or tail leading edges). To meet these regulations, both bird strike tests are conducted experimentally and also analyses based on numerical simulation are made in computer environment due to expensiveness of these tests. Choosing the proper parameters in the tests and the analyses is very important in order to be able to pre-determine the damage following a real bird strike event and to design related components in accordance with these parameters. This paper reviews theoretical background, the finite element analyses (based on substitute bird materials, bird modelling methods, bird geometry) and related tests about bird strike problem. [ABSTRACT FROM AUTHOR]

This paper presents kinematic, static and fatigue analyses of straight cup hinge with brake which is widely used in the furniture industry. The solid model of the hinge is created by using packaged programme. The kinetic and kinematic anayses of hinge are performed by use of multiple body analysis programme. The quasistatic analysis of the structure is made due to the support and joint forces which are obtained as a result of the kinetic and kinematic analyses. The analyses are carried out by considering the standard TS EN 15570. Related to the evaluation of fatigue analysis, modifications are proposed for the structure. The results of kinetic and kinematic analyses adopted to static and fatigue analyses due to finite element method is shown as an alternative to the transient response of the finite element method. [ABSTRACT FROM AUTHOR]

It is possible to increase the machined workpiece accuracy and productivity during turn-milling operation by modeling the cutting forces and thermally induced deformations on cutting tool. In order to achieve this task, the main objective of this study is to determine the thermally induced deformations on tool during turnmilling operation and reduce them by applying pressurized cooled air. In this study cutting forces, tool temperatures and deformations modelled by FEM coupled with analytical and mechanistic expressions are compared to those obtained by some series of experiments. It was shown in the study that those deformations could be upto 40% of the depth of cut during fine turn-milling. However they can be reduced by means of cooled air by 65%. Furthermore, tool wear and surface roughness values of machined workpiece were also measured and as it is stated in the paper that the surface values in fine turn-milling operation could be as good as they are in grinding operation. [ABSTRACT FROM AUTHOR]

In this paper, thermal analysis of high voltage (HV) power cable joint, which is well-known as the hottest point of underground cable route, is investigated using finite element method (FEM). For this purpose, a 154 kV cable and joint, which are installed in underground transmission system in Turkey by TEIAS according to IEC-60287 standard, are used in analyses by using ANSYS 5.6 finite element analysis software. The first aim of this paper is to determine temperature distribution of cable joint and to compare with the cable parts. The second aim of this study is to give fundamentals and boundary conditions to analyse the ampacity of an installed cable considering IEC-287 standard as a basis. This standard uses Neher-McGrath model, which uses a technique based on a simple model of energy balance in the conductor of the cable, and on an analogy between the flow of electric current and the flow of heat. Obtained results indicate that joint layers have a less heat dissipation characteristic than cable parts due to excessive volume. Therefore the joint insulation is exposed to more thermal stresses and its aging process is accelerated. [ABSTRACT FROM AUTHOR]

In this paper, a new test method to determine biaxial flexural tensile strength of cement based materials is proposed. A mortar triangular plate specimen is supported on three small spherical silver balls and loaded externally on a small spherical silver ball from the center of gravity of specimen. Yield line theory (YLT), which is a kinematic method of plastic analysis, is used to drive a simple equation for biaxial flexural tensile strength of cement based materials. In order to verify the derived equation, lots of triangular and prism mortar specimens were produced and tested according to the proposed model and three-point flexural test, respectively. Moreover, finite element analysis is also used to verify the derived equation and the results obtained from the experimental studies. It was concluded that FE analysis and experimental studies verified the proposed method and the derived closed-form equation for biaxial tensile strength of cement based materials. Experimental results also exhibited that biaxial tensile strength measured by proposed method is about 22% lower than that of the flexural strength obtained from three-point flexural test. [ABSTRACT FROM AUTHOR]

The shielding efficiency of cylindrical shields for three phase underground cable is investigated for several shields material using finite element method (FEM). This FEM model takes into account the nonlinear hysteretic behavior for ferromagnetic material in the shield. The shields are cylindrical shaped and the power cables are positioned in flat configuration. The shielding efficiency is compared for shields with the same geometry but several shielding materials with nonlinear hysteretic behavior (Magnetil and DX52, both from Arcelor-Mittal firm) and a non-ferromagnetic and electrically conducting shielding material (Aluminium). The paper investigates the influence of several parameters on shielding efficiency: the size of the shield radius, the current amplitude in the cable and the thickness of the shield. Magnetil shield material is the best in terms of shielding performance. The numerical models are validated with experimental results for without shield. [ABSTRACT FROM AUTHOR]

Distraction osteogenesis is a common clinical procedure to correct mandibular retrognathia cases. In spite of consolidated clinical use, lots of questions still remain to be answered concerning distraction osteogenesis. One of them is to determine the best screw configuration providing boneremodelling in a healthy way due to the stabilization of callus. In this study, some suggestions will be presented about the points "what best screw locations are" and "what the optimum screw quantity is". A three dimensional solid model was obtained by processing patient-specific computed tomography data in DICOM format. Teeth, cortical and trabecular bone segments were modelled separately with the segmentation process. Ramus and corpus segments were separated from each other by virtual surgery and corpus segment was positioned 11 mm forward. The distractors modelled were assembled into the mandible after modelling the callus. The volume meshes created for all the parts were transferred to a finite element software. Finite element analyses were run as bilaterally symmetric which means the same screw configurations were set for both sides of the mandible. The studies carried out in this paper have shown that screws located closer to the osteotomy line provide more stability, and triangular configuration has a better impact on stability than linear configuration. The reference stabilization case was identified as the scenario of using 22 screws in total, including 8 screws in ramus segment and 14 screws in corpus segment. This case was assumed as maximum stabilization case and other analyses were compared with this result. The results of the configuration including triangularly located 3 screws in ramus segment and closely located 2 screws near the osteotomy line in corpus segment have shown similarity with the reference stabilization case. The closest configuration to the reference case has been tried to determine by using as few screws as possible and has been recommended for clinical use. [ABSTRACT FROM AUTHOR]

In this paper, the different working structure and unique design of the E-Core Transverse Flux Machine that is combined of transverse flux and reluctance principle is investigated for training bike application. Also, static magnetic characteristics of the machine are obtained with finite element analysis and experimental measurements. The modeling of the E-Core Transverse Flux Machine and its driver system are given. The whole system with all control algorithms for a training bike application is simulated and the performance curves are presented. Finally, the experimental tests done at the laboratory for the indoor training bike application are compared and verified with the results of the simulation. [ABSTRACT FROM AUTHOR]

In this paper, new educational software developed for Design of Steel Structures lesson is presented. The software is named as STR2 and developed by using MATLAB which is a mathematical tool. All design steps can be monitored by using the software. To analyze the structure, the user do not assign loads to joints and elements, self-load of system, snow load and wind load are assigned to system automatically. Finite Element Method is used for structural analysis. The structural system can be designed according to TS648. [ABSTRACT FROM AUTHOR]

Transfer of tensile forces from reinforcing steel into the surrounding concrete affects the behavior of reinforced concrete members. This transfer relies on the bond action between the steel and the concrete. Under monotonic loading the part of bond strength due to chemical adhesion is easily exhausted and bearing against the lugs is the primary load-transfer mechanism at loads near the ultimate. These stresses cause internal cracking of concrete at the steel-concrete interface. This paper deals with the finite element modeling of the bond-slip and its application due to internal cracking of the first layer of concrete surrounding the bar and the bending and/ or cracking of the small concrete teeth near the bar lugs. A previously proposed constitutive steel stress-bond slip relation by Mirza and Houde (1979) was used in finite element analysis of reinforced concrete shear wall specimens and the results were presented. [ABSTRACT FROM AUTHOR]

Transfer of tensile forces from reinforcing steel into the surrounding concrete affects the behavior of reinforced concrete members. This transfer relies on the bond action between the steel and the concrete. Under monotonic loading the part of bond strength due to chemical adhesion is easily exhausted and bearing against the lugs is the primary load-transfer mechanism at loads near the ultimate. These stresses cause internal cracking of concrete at the steel-concrete interface. This paper deals with the finite element modeling of the bond-slip and its application due to internal cracking of the first layer of concrete surrounding the bar and the bending and/ or cracking of the small concrete teeth near the bar lugs. A previously proposed constitutive steel stress-bond slip relation by Mirza and Houde (1979) was used in finite element analysis of reinforced concrete shear wall specimens and the results were presented. [ABSTRACT FROM AUTHOR]

Functionally gradient material (FGM) idea was proposed in 1980s in order to be used in preparation of thermal resistant materials. The microstructure of functionally gradient material (FGM) is characterized by a spatially varying manner on the macro scale. In thermal barrier structures, functionally gradient materials are composed from ceramic and metal. In the thermally more active surface, the ceramic content is richer. Towards to the other surface ceramic content decreases and the metal content increases. The composition of material changes continuously and smoothly throughout the thickness of the plate. In laminated composite materials, debonding of layers and initiation of cracks can be observed because of mismatch of layer mechanical properties. Additional problems like the presence of residual stresses due to the difference in thermal e×pansion coefficients can occur in the composite materials. Aforementioned problems for laminated composite materials can be avoided or reduced by gradually varying the volume fraction of the constituents rather than abruptly changing them across an interface. In recent years, numerous researches about functionally gradient materials have been conducted for their usage in planes, space ships and nuclear systems. Mi×ed finite element methods developed from several variational principles was used frequently in the literature as an alternative of displacement based finite element methods. Mi×ed and hybrid finite element methods are generally developed by using HuWashizu functional, Hellinger-Reissner functional or Gateau× derivative. In mi×ed finite element methods, internal forces are also nodal independent variables as displacements. This property brings some analytical and computational advantages to the method. One of them is the higher accuracy in the internal forces. Also lower continuity requirements of shape functions with respect to displacement based elements; result in simpler finite element formulations. In this paper, nonlinear static behaviors of laminated composite plates and functionally graded plates are investigated with mi×ed finite element method. For this purpose, a mi×ed finite element program based on thin plate theory is developed and the analyses are conducted with this. Geometrically nonlinear effects are taken into consideration in the sense of von K×00E1;rm×00E1;n plate theory. In this theory straindisplacement relations are obtained with the assumption of small strains and moderate rotations. Nonlinear mi×ed finite element functional is developed with Hellinger-Reissner functional and linearized with incremental formulation. In order to improve the results of the incremental procedure and prevent the increase of errors after several steps, an iterative procedure, the Newton-Raphson algorithm is imposed. Finite element matrices and vectors are formulated with isoparametric quadrilateral elements by using C0 continuous shape functions. The functionally gradient material property variation through the thickness of the plate is assumed to be in terms of a power law distribution. And this variation is modeled in a layer wise manner. The developed mi×ed finite element program is verified with problems in the literature by analyzing a laminated composite plate. As a result of obtained solutions, it is shown that, the developed mi×ed finite element program is able to find sufficiently precise results. Afterwards, functionally graded plates consisted of aluminum and zirconia materials, are solved by both linear and nonlinear analyses under uniformly distributed load. In the analyses five different material variation parameters and simply supported boundary conditions are considered. The plate is modeled with an 8×8 mesh having 10 layers. The obtained solutions are compared with the results from literature. In functionally graded plates, the geometrically nonlinear effects reduce the vertical displacements at the plate center. Also when the material variation parameter is selected between 0 < n < ∞, the calculated vertical displacements lie in between the results of the plates with n=0 and n=∞ variation coefficients. As a result, it was shown that, nonlinear behavior of laminated composite plates and functionally graded plates can be determined realistically by using the developed mi×ed finite element program. According to the knowledge of the authors, there is no work for the analysis of functionally graded plates by the mi×ed finite element methods [ABSTRACT FROM AUTHOR]

Devastating earthquakes takes place in Turkey and other parts of the world. Suspension bridges represent critical nodes of major transportation systems. Especially in important metropolis, bridges have a strategic importance. Bridge failure poses not only the greatest threat of fatalities from a single devastating earthquake but causes a substantive interruption of emergency efforts. Istanbul has two suspension bridges in service, namely the Bosporus Bridge and Fatih Sultan Mehmet Bridge which provide a major transportation link between the two parts of Turkey, and also join together the European and Asian parts of Metropolitan city. In this paper, sophisticated three-dimensional finite element model of Fatih Sultan Mehmet suspension bridge is developed and the results of the free vibration analysis are presented. In addition, Dynamic parameters of the Fatih Sultan Mehmet Bridge are determined by means of full-scale Ambient Vibration Test at no-traffic condition. Fatih Sultan Mehmet Bridge is a modern suspension bridge, and ranks as the 11th among the longest suspension bridges in the world. The bridge, which was commissioned in 1988, has a main span of 1090.00m. It is a gravity-anchored suspension bridge with no side spans and with steel pylons and double vertical hangers. The daily traffic of the bridge is approximately 220, 000 vehicles. This traffic consists of a combination of local commuters and trans-European commercial transportation. While three dimensional model of the bridge was prepared, great care was given to boundary conditions and links to coincide with actual values. The three-dimensional finite element model of the bridge is developed including geometric non-linearity effects that consist of cable sagging and stress stiffening, the cumber of the deck, and the set-back of the towers. In addition, structural components such as rocker bearings of the bridge are also modeled. The rocker bearings directly affect the deck modes. Defining the hinge supports of the rocker bearings is essential for modeling accuracy. In this study, rocker bearing is modeled as in real structure. Due to the fact that this bearing has great impact on the mode shapes and orders of deck, in these kinds of finite element modeling work, it should be taken into consideration. Non-linear behavior of the flexible long-span three-dimensional bridges is caused by geometric type of deformations. The nonlinear geometric effect due to the cable tension is taken into account by using geometric stiffness matrices. In order to establish the deformed configuration for the dead load, an initial geometric nonlinear analysis is needed. The earth-quake response of the bridge in the analysis starts after the application of the dead load. Therefore, it is necessary to perform a non-linear static analysis to compute the stiffness matrices of the bridge in its dead-load deformed configuration before a dynamic analysis can be performed. For this purpose an iterative scheme for the static analysis is performed by means of a tangent stiffness matrix approach. Hence, natural frequencies and the corresponding mode shapes are calculated using an accurate 3-D finite element model. Physical and analytical understanding of the dynamic response of a suspension bridge is very dependent on the knowledge of its natural frequencies, damping and normal mode shapes of vibration. Performing actual tests on a full-scale structure is the only sure way of assessing its dynamic parameters. Dynamic parameters of a suspension bridge can be determined by means of Ambient Vibration Survey (AVS). Measurements of ambient vibrations were made on Fatih Sultan Mehmet Bridge in order to determine the natural vibration frequencies for the vertical, lateral, torsional, and coupled modes with a 2 Hz resolution, with no traffic load. The ambient vibration survey data are analyzed using basic identification techniques based on the Fast Fourier Transform (FFT) method. The reliability of the model is examined by comparing the natural frequencies of the finite element model with those identified from the ambient vibration tests. Comparisons are also provided with the previous experimental and analytical studies conducted on the bridge. The finite element results of the current study for the modal frequencies as well as the classification of the modes by their dominant actions are compared with the finite element study conducted by Prof. Brownjohn (Brownjohn et. al., 1992). Even though the assumptions of both studies differ, there is close agreement between the results. Reasonable agreement exists between the finite element study and the ambient vibration test for the modal frequencies investigated in this study. [ABSTRACT FROM AUTHOR]

In Norm Fasteners Co. die failure analysis and fatigue life estimations have been done since 2003. By using Finite Element Analysis; material flow, die filling, lap formation, forging forces, ductile fracture and tool failures can be predicted before production. Necessary changes in design are made to produce defect-free product in shortest time and to lower cost. A few case studies experienced in Norm Fasteners Co. about estimation and improvement of die service life by modifications in process as well as in die design and estimation of hardness distribution of final part are presented in this paper. [ABSTRACT FROM AUTHOR]

In this paper, it is carried out the spread of plastic zones and the stress analysis at the composite plates with laminated thermoplastic (Polyvinyl Chloride) subsisting an elliptic hole in the middle part. The composite plates with steel fiber reinforcement of woven-shaped consist of four orthotropic layers bonded symmetrically in the form of [θ0-θ0]². The plates are subjected to uniformly distributed vertical loads. Loading is realized by iterations number of 25, 50, 75 and 100 by increments 0.0001 MPa by starting from the yielding point of plate for the chosen each reinforcement angle. According to the load steps and the different reinforcement angles, the values of the plastic stresses occurring in the composite plates are obtained by Finite Element Method. The obtained results present that the plastic zones in the plate appear in the lower and upper surfaces but not in the intermediate surfaces. It is also observed that the stress components at the intermediate layers are less than that of the lower and upper surfaces and the plastic stress components increase depending on the iteration number. [ABSTRACT FROM AUTHOR]

Surface geology and the geotechnical properties of near surface soil layers have important effects on the earthquake ground motion. Site effects can be defined as the variation in the characteristics of incoming wavefield such as amplitude, frequency content and duration because of the geotechnical, dynamic and geometrical properties of soil layers and surface topography. The main source of site effects is the specific impedance contrast between near surface and deep soil layers. The calculation methods which were developed for the dynamic analysis of soil layers are defined as one, two and three dimensional. In one dimensional approach the soil medium is assumed as horizontally layered for simplicity and the analyses are based on the principal of body waves travelling up and down in the near surface layers. However, in fact sedimentary deposits form mediums which can only be defined by 2 or 3 dimensional methods. This kind of deposits with lateral geological discontinuities show trap behaviour. This trap affects the surface waves which develop during earthquakes and reverberate back and forth on the interface of sediment deposit and bedrock. As a result, the amplitude of surface ground motions may show variation dependent on the site where it occurs, also the frequency content of this surface motion will differ from site to site at the edge of deep deposits. In this paper, two dimensional basin edge models with four different slope values (H/D=10, 5, 2, 1) were constituted to investigate the effects of basin edge on the variation of surface motion under earthquake excitations with different frequency content. Duzce basin shear wave velocity profile, which had been obtained from the analyses of microtremor array and single point measurements, was used to form the two dimensional geometry of soil layers and bedrock in the basin edge models. One (1D) and two dimensional (2D) dynamic analyses were performed for six different bedrock acceleration records by using these basin edge models. The results which would be obtained from the 1D and 2D analyses were aimed to reflect the seismotectonical structure of the faults in Turkey. Therefore four bedrock acceleration time histories were selected among the Turkey earthquakes. In order to eliminate the "box effects" which can occur during the two dimensional dynamic finite element analyses because of the model geometry and boundary conditions; viscous dashpots, which are calculated proportional to the shear and pressure waves of the relevant layers, were put at the vertical and horizontal layers.… [ABSTRACT FROM AUTHOR]

Back emf methods have been widely used in position and speed sensorless control of permanent magnet synchronous motors. In this method, it is conjectured that the back electromotive force induced on the stator windings by the rotor permanent magnets are sinusoidal. This conjecture causes errors in the estimation of speed and position. In this paper, the flux of stator winding was analysed by using finite element method, and the findings were used in position and speed sensorless field oriented control of permanent magnet synchronous motor. The validity of the proposed method was demonstrated by using Matlab Simulink program. [ABSTRACT FROM AUTHOR]

This paper presents multiobjective fuzzy genetic algorithm optimization approach to a submersible motor design. Utilizing the concept of fuzzy sets and convex fuzzy decision making, the motor design task is formulated as a multiobjective fuzzy optimization problem and solved using a genetic algorithm. The two-dimensional Finite Element Method (FEM) is then used to confirm the validity of the optimal design. The optimization results show the effectiveness and achievement of the proposed method. [ABSTRACT FROM AUTHOR]