Results Of Finite Element Method Analysis Research Articles

Development of Structural Design Method for Twisted Wires Suspension

Copper alloy suspension wires are used in the optical pickups and image stabilization mechanisms of mobile cameras. The durability of suspension wires used in mobile cameras is greatly affected by the increase in the weight of the lens assembly as makers improve the image quality of the camera. Therefore, the durability of the wire needs improvement. In this study, the stress reduction effect of twisted suspension wires was investigated using finite element method (FEM) analysis. In addition, a practical equation was obtained to facilitate the structural design. From this study, the following conclusions were obtained. In contrast to the conventional single-wire structure, the twisted wire structure enables a significant reduction in the stress generated while maintaining the stiffness. A simple formula that approximates the results of many FEM analyses was developed to enable rapid product design.

Shock absorption capability of corrugated ring yield mount subjected to high impact loading

Various types of mechanical energy-absorbing devices are known that operate by plastic deformation. The corrugated ring mount that is used in this study relates to a device that absorbs energy by plastic deformation. This energy-absorbing device has reduced volumetric proportions, simple in design, and therefore has small overall dimensions and can be mass-produced at low cost. This study aims to determine the shock absorption capability and efficiency of this mount against impact loading. For this, Finite Element Method Analysis (FEA) and experimentation are done. The FEA is done using the Explicit Dynamics (AutoDyn) module of ANSYS Workbench and for experimentation Drop Test Machine (DTM) is used. In this study impact load from low g up to 85 g is applied and a very close agreement is found between FEA and experimental results. There is just a 5–10% deviation between the findings. The results show that this mount is plastically deformed to absorb the impact energy with a maximum efficiency of 70%. It concludes that it is a reliable and safer shock energy device.

Evaluation of a newly developed low reflection dummy load for high power millimeter waves

A low reflection dummy load (LRD) has been newly developed for gyrotron development and operation. This LRD is designed for 0.5 s of high power (∼1 MW) millimeter wave injection with a low reflection. In order to reduce the reflection, the LRD consists of an inner cylinder, a main chamber, and a conical mirror, which results in the efficient absorption by long pass length between the inner cylinder and the main chamber. The characterization of low reflection has been demonstrated by the water temperature rise of the DC break (DCB) section inside the gyrotron, which works as an indicator of the reflected stray millimeter wave from the dummy load (DL). The water temperature rise of DCB with LRD was decreased by 1%, 15% and 17% at three tested frequencies of 82 GHz, 110 GHz and 138 GHz, respectively, compared with the conventional DLs, and the power absorption of LRD is 4–7% larger than the conventional DLs. A thermal analysis by a finite element method (FEM) with experimentally obtained heat load distribution and cooling time constant showed that the maximum temperature at 0.5 MJ injection is below the melting point of the material but it is not acceptable for the cycle operation considering the allowable stress of the aluminum-alloy used in the present design. FEM analysis suggested that changing its material to CuCrZr enable to use for 0.5 MJ injection. The result of FEM analysis also shows that the CW injection with less than 0.15 MW is acceptable in the present design.

Optimal design of high-speed permanent magnet synchronous generator based on NSGA-II considering mechanical properties

Although the finite element method (FEM) is highly reliable, it is time-consuming and expensive, for example, substantial computing costs are incurred for coupled analysis while considering the mechanical and electromagnetic properties. Therefore, in this paper, a high-speed permanent magnet generator's electromagnetic and stress characteristics have been mathematically derived, and the optimal point is selected based on NSGA-II. The objective functions are power density and efficiency, with the constraints being the current density, slot fill factor, core saturation, voltage limit, and rotor safety factor. The method presented in this study was verified via FEM analysis and experimental results of the optimal model.

A low-frequency micro-vibration absorber based on a designable quasi-zero stiffness beam

This paper presents a low-frequency micro-vibration absorber based on a beam with designable nonlinear stiffness. The material and dimension parameters of the nonlinear characteristics of the beam are discussed by the finite element method (FEM). Based on the nonlinear stiffness characteristics of the beam, the designed micro-vibration absorber has a low-frequency vibration absorption effect and multiple working modes in multiple directions. The effects of structural parameters on the stiffness characteristics of the designed beam are discussed to explore the low-frequency performance. The results of FEM analysis are verified by vibration absorption experiments, and the effectiveness of the low-frequency vibration absorbers is verified by aerospace micro-vibration experiments.

NUMERICAL INVESTIGATION OF THE IMPELLER BLADES, MANUFACTURED BY METAL 3D PRINTING TECHNOLOGY WITH INTERNAL STRUCTURES

This paper presents the results of FEM (Finite Element Method), CFD (Computational Fluid Dynamics) and modal analyses of model semi-axial pump. Two sets of impeller blades were printed by metal 3D printing technology with internal honeycomb structures. The set of solid blades, manufactured by CNC machining for a comparison, was also included. 3D printed blades were designed with internal structures in order to save material, and with respect to mechanical and dynamic properties. Saved material can change the starting moment, modulate modal properties or decrease strength properties. The 3D printed blades can be produced very quickly and with accurate blade surface finish. One of the reasons of this approach can be the use of 3D printed blades as spare parts for industrial applications or for model pump research. This paper contains short introduction to blade design with internal honeycomb structures and their one-way FSI analyses (Fluid Structure Interaction). The final results of best design are presented and discussed.

Optimal Design of an Inverter-Fed PMSM for a Brake System Considering Variation in Motor Control Parameters and Input Voltage

This study proposes an optimal design approach for an inverter-fed permanent magnet synchronous motor (PMSM) considering the variation in motor control parameters and input voltage (inverter output voltage), which vary with respect to the temperature and loading conditions, in an integrated brake system. In an integrated brake system, a quick response to load changes is crucial. Therefore, in this study, to consider the fluctuation in control variables and input voltage, the motor control parameters and input voltage were first calculated according to the operating temperature and loading condition. Subsequently, based on the calculated conditions and the approximated motor input voltage and control parameters, the objective functions corresponding to motor characteristics in transient and steady states were formulated using design-of-experiment (DOE), the moving least square method (MLSM), and the finite element method (FEM). Finally, the optimal design was performed using the genetic algorithm (GA). The validity of the proposed optimal design approach was verified by comparing its optimization results with the FEM analysis results. Thus, it was confirmed that a motor can be designed for an integrated brake system by considering the motor control parameters and motor input voltage, which vary with the driving conditions.

Design and Analysis Considering Magnet Usage of Permanent Magnet Synchronous Generator Using Analytical Method

In this study, the characteristic analysis of a permanent magnet synchronous generator was performed using the analytical method, and the validity of the analytical method was compared with that of the finite element method (FEM). For the initial design, the rotor size was selected using the torque per rotor volume method, and the stator size was selected according to the saturation of the stator iron core. In addition, fast Fourier transform analysis was performed to determine the appropriate magnet thickness point, and it was confirmed that the open circuit and armature reaction magnetic flux densities were consistent with the FEM analysis results. Based on the analytical method, the generator circuit constants (phase resistance, back EMF, and inductance) were derived to construct an equivalent circuit. By applying the equivalent circuit method to the derived circuit constants, the accuracy of the equivalent circuit method was confirmed by comparing the FEM and experimental results.

Mechanical Properties of Aluminum Metal Matrix Composite Reinforced with Silicon Carbide using FEM

In this work the SiC reinforced Alumunium composites were studied and Finite Element Method (FEM) analysis carried out and the results of FEM analysis were compared with the actual experimental results. As the Finite Element Analysis has become a major tool for an engineer, the Finite Element Analysis is done to solve advanced analysis issues. In this paper, Finite Element Method based ANSYS software is used to determine the mechanical properties in the aluminium metal matrix composite reinforced with Silicon Carbide by changing the volume fraction of the Silicon Carbide in aluminium. The FEM analysis results were compared with the actual experimental result. The testing if the mechanical properties such as tensile testing and compression testing we carried out in the FEM analysis.

Structural Design and Dynamic Analysis of Carbon Fiber Reinforced Plastic Shaft with Metal Parts

It is important to improve dynamic performance of rotating machinery by reducing the mass of shaft and increasing the natural frequency. Many studies have focused on dynamic characteristics of shaft in rotating machinery with the utilization of composite material. This paper mainly investigates the structural design and dynamic analysis of a CFRP/Metal hybrid shaft. The finite element method (FEM) has been used to determine the selection of design variables include fiber orientation angle, layers stacking sequence and layers thickness. Also, experimental test was carried out using a FFT analyzer with impact hammers. The differences between the FEM analysis result and the experiment test result were respectively less than 4.5% and 6.3% for the first two natural frequencies; therefore, the results of FEM analysis are acceptable. The results reveal that the fiber orientation angle is the most significant factor affecting the dynamic characteristics of CFRP/Metal hybrid shaft. In addition, there have some effect of the layer stacking sequence on natural frequency.

Fabrication of a piezoelectrically driven micropositioning 3-DOF stage with elastic body using a multi-material 3D printer

Purpose This paper aims to propose a method for manufacturing multi-material monolithic structures with flexible materials to construct the elastic body by using a dual-nozzle three-dimensional printer to develop a piezoelectric (PZT)-driven micropositioning stage with three degrees of freedom (3-DOF) and flexure hinges. Design/methodology/approach Polylactic acid (PLA) and nylon were used for the lever structure’s frame and flexure hinge, respectively. Additionally, the stage consisted of three PZT actuators for fine movement in the nanometer scale in 3-DOF (x, y and θ-directions). For the design of the stage, the kinematic analysis model and the finite element method (FEM) analysis was undertaken for comparing between PLA with nylon (multi-material), PLA (single material) and aluminum (conventional-material). In addition, two verification experiments were implemented for the fabricated prototype stage. First, to evaluate various assessments (lever ratio, hysteresis, coupling error and resolution), a measurement is carried out using the three capacitive sensors. Then, a two-camera-vision measurement experiment was performed to verify the displacement and lever ratio over the full-scale working range of the fabricated positioning stage, and the results from the experimentation and the FEM analysis were compared. Findings The authors confirmed enhancements in the properties of the lever structure frame, which requires stiffness and of the hinge, which requires flexibility for elastic deformation. Comparing FEM analysis and experimental results, although the performance as shown by experimental results was lower: the maximum difference being 3.4% within the end-point working range; this difference was sufficient to be a plausible alternative for the aluminum-based stage. Originality/value Multi-material monolithic-structure fabrication has an effective advantage in improving the performance of the stage, by using a combination of materials capable of reinforcing the desired characteristics in the necessary parts. It was verified that the fabricated stage can substitute the aluminum-based stage and can achieve a higher performance than single-material stages. Thus, precise-positioning stages can be manufactured in many kinds of structures with various properties and contribute to weight reduction and low costs for application equipment.

Comparison of experimental, analytical and simulation results for hot rolling of S275JR quality steel

Hot rolling allows the material to be shaped in successive steps in different steps since the material is at a temperature above 0.5Tm which is the recrystallization temperature and gives the possibility of deformation with large deformation rates. In the industry, direct applications show negative effects on time and cost. Practical processes by experimenting can be completed in short periods in some symmetrical profile section products and long periods in some asymmetric profile section products. Finite element method (FEM) can be applied in order to predict the results obtained by simulating the designed calibrations in the computer environment before testing in the rolling mill. In this study, the production of HEA 240 profile in S275JR quality is experimentally made in 21 passes and the geometric dimensions of the first three passes of this structure was compared with 3D FEM analysis results. The comparison results are compatible and high similarity ratio as 95–99.1% was found. Following to this, the analytically calculated dimensions of calibrated IPE 140 profile in S275JR quality was compared by the verified 3D FEM analysis. Considering the first 5 passes of 15 passes for saving time, the simulation and analytical results are in close relationship less than 5% deviation ratio. It is possible to say that this simulation, which has small acceptable differences, has a significant effect on minimizing losses in production processes and achieving production targets.

Novel piezoelectric rotary motor driven by a single-phase sine wave with an asymmetric stator.

This study demonstrates a new approach for constructing a rotary piezoelectric motor that utilizes an asymmetric stator driven by a single-phase signal. An asymmetric stator with four driving feet is proposed on the basis of the idea of generating asymmetric action on the rotor. This new motor consists of one piezoelectric transducer with two anchors and four driving feet placed in a parallelogram and internally connected to a circular rotor. The four feet vibrate asymmetrically to push the rotor into motion in one direction when a preload is applied. The proposed motor is designed, analyzed, and tested by using a finite element method (FEM). The vibration and impedance characteristics of the stator are measured after fabricating a prototype, and the test results are consistent with the FEM analysis results. The typical output of the prototype is a no-load speed of 176.5 rpm and a maximum torque of 29.4 N mm at an excitation voltage of 274 Vp-p.

Finite Element Analysis of Heat Treated Wood Filled Styrene Maleic Anhydride (SMA) Copolymer Composites

The computer aided three dimensional static analyses of the specimens was done by using the Finite Element Method (FEM) and obtained data was compared with actual test data. The aim of this study is to compare the deformation/stress analyses with FEM analysis results of styrene maleic anhydride (SMA) copolymer composites. The heat treated wood/SMA copolymer composites were produced from different loadings (from 10 to 30 wt. %) of heat treated and untreated eastern white pine wood flours (Pinus strobus L.). All formulations of wood flour/SMA copolymer composites were produced by melt compounding through injection molding. The deformation/stress results obtained from the experimental solutions are very close to the results obtained from the numerical solutions (SAP2000 V17). As a result, it can be said that it is beneficial to use the FEM in the engineering design approach after the data obtained by the experimental solutions as meaningful values after application of the FEM.

Research on the Load-Sharing Principle of a Novel Piezoelectric Dynamometer

The range of three-dimensional piezoelectric sensors in two tangential directions, depending on the maximum static friction force generated by axial preload, is usually only one-fifth of the axial preload, or even lower. It greatly limits the application of piezoelectric sensor in those situations where tangential measuring range is equal to or larger than axial measuring range. This article proposes a method that uses split cylindrical pins to realize load sharing only in tangential direction, and then establishes a load-sharing mathematical model based on the radius of cylindrical pin. Finally, Finite Element Method (FEM) is used to analyze load-sharing stability of 10 mm cylindrical pin and split pin. A load-sharing experiment based on a three-dimensional piezoelectric dynamometer with a tangential range of 1kN and an axial range of 5kN is designed. The experimental results indicate that the tangential load-sharing ratios are 21.4% and 23.0%, the axial load-sharing ratio is 81.0%, which is agree well with the results of FEM analysis. It proves that the static measurement accuracy of the piezoelectric dynamometer in axial direction is not affected. Great load-sharing performance in tangential direction but little load-sharing performance in axial direction can be realized by using split cylindrical pins.

Stress analysis of pressure-assisted sintering for the double-side assembly of power module

PurposeCrack and stress distribution on dies are key issues for the pressure-assisted sintering bonding of power modules. The purpose of this research is to build a relationship among stress distributions, sintering sequences and sintering pressures during the sintering processes.Design/methodology/approachThree sintering sequences, S(a), S(b) and S(c), have been designed for the double-side assembly of power module in this paper. Experiments and finite element method (FEM) analysis are conducted to investigate the crack and stress distribution.FindingsThe sintering sequence had significant effects on the crack generation in the chips during the sintering process under 30-MPa pressure. The simulation results revealed that the module sintered by S(a) showed lower chip stress than those by the other two sintering sequences under 30 MPa. In contrast, the chip stress is the highest when the sintering sequence follows S(b). The simulation results explained the crack generation and prolongation in the experiments. S(a) was recommended as the best sintering sequence because of the lowest chip stress and highest yield rate.Originality/valueThis study investigated the stress distributions of the double-side sintered power modules under different sintering pressures. Based on the results of experiments and FEM analysis, the best sintering sequence design is provided under various sintering pressures.

Plastic Deformation Simulation of Sintered Ferrous Material in Cold-Forging Process

A cold forging process of Mo-alloyed sintered steel was simulated by finite element method (FEM) analysis considering density change in the process. Moreover, the effect of sintering time on the behavior of the densification and the plastic deformation of it in the cold-forging process was also investigated. Using the true stress-true strain diagram obtained by the compression test with a sintered specimen, the modified true stress-true strain diagram was derived for large plastic deformation analysis with the porous material model. The result of FEM analysis for the cold compression process of the sintered specimen revealed that the analysis can simulate the shape of the excessive metal part and density change of it. Also, it was found that local deformation becomes large and thus the excessive metal part extends with increasing sintering time although the difference in the true stress-true strain diagrams is negligible.

Investigation on the adhesive characteristics of Engineered Cementitious Composites (ECC) to steel bridge deck

As a common form of deterioration, the interfacial de-bonding between the steel bridge deck and pavement layers significantly affects the operation of steel bridges. This study proposed a medium early-strength Engineered Cementitious Composites (MES-ECC) with high ductility as the steel bridge deck pavement material. The adhesive characteristics of MES-ECC to steel deck/stone mastic asphalt (SMA) mixture with epoxy resin and to steel plate with cotters were investigated via shear test and push-out test, respectively. Additionally, the theoretical shear stress of MES-ECC/steel deck under quasi-static loading was analyzed using finite element method (FEM). Tested material performance results show that the MES-ECC possesses high ductility, meanwhile, the compressive and flexural strength of the MES-ECC at 3 days can reach 26 and 8 MPa, respectively, allowing the steel bridge to open traffic earlier, thus shorten the construction period. Considering the avoidance of slipping of interlayers between MES-ECC and steel deck/SMA layer at different temperature exposures, the optimal epoxy resin dosage for interlayers of MES-ECC/steel plate and MES-ECC/SMA obtained from shear tests is 0.4 and 0.6 L/m2, respectively. The push-out test shows that the MES-ECC exhibits superior interaction effects with cotter in steel plate with higher ultimate push load and deformation in comparison with normal concrete and mortar. Finally, the results of FEM analysis indicate that the interfacial bonding mentioned in this study can satisfy the theoretical requirements of steel bridge deck pavement under quasi-static loading.

Characteristic Analysis of High-Speed Permanent Magnet Synchronous Motor

Background/Objectives: This paper presents characteristic analysis of High-SpeedPermanent Magnet Synchronous Machine (High-Speed PMSM) by using FEM (Finite Element Method) tools. The High-Speed PMSM need the protective tube with non-magnetic materials that protect the scattering of permanent magnet, it is necessary that analyzed about mechanical analysis.Methods/Statistical analysis: For preventing and improving, the fracture of the rotor of High-Speed PMSM, it is important that analyzed characteristic of mechanical stress, it should not be analyzed that occurred the fracture and decreased the performance, since the structure of rotor. However, structure analysis is usually performed by using FEM, which need the big amount of time consuming. Therefore, in this paper is derived the mechanical stress of rotor by using analytical method of stress.Findings: The results of the stress analysis are compared with the results of FEM analysis that validated the analytical method of stress analysis. Based on the results of the analysis, an analytical model was fabricated. Through the experiments, the presence of rotor breakage was examined and the performance was measured.Improvements/Applications: It can be applied to stress analysis and characterization of superhigh speed machine through the analysis methods presented in this paper.

Design and Operational Test of Large-sized HTS Magnets with Conduction Cooling System for a 300 kW-class Superconducting Induction Heater

AbstractIn this paper, we presented design specifications and operational test results of large-sized high temperature superconducting (HTS) magnets for Superconducting Induction Heater (SIH). HTS magnets were designed and fabricated with the metal insulation method. Critical currents of the HTS magnets were estimated by considering the angular dependency on the magnetic flux density of HTS tape. The characteristic resistance, the charging and discharging time were calculated and measured in the liquid nitrogen and the conduction cooling condition achieved with the 2nd stage GM cryo-cooler. The saturated temperature of the HTS magnet reached at 5.6 K. The performances of the large-sized HTS magnet including cooling and magnetic field characteristics were tested under the conduction cooling. These results were evaluated with those of finite element method analysis results. The characteristic analysis results of the large-sized HTS magnets will be applied for development of the commercial 300 kW SIH.