A Research of Actuators for Micromirror Control

2003 International Electronic Packaging Technical Conference and Exhibition, Volume 2 ◽

10.1115/ipack2003-35123 ◽

2003 ◽

Author(s):

Hiroki Mamiya ◽

Koji Ishikawa ◽

Qiang Yu

Keyword(s):

Fem Simulation ◽

Statistical Design ◽

Vertical Displacement ◽

Operating Voltage ◽

Torsional Motion ◽

Surface Method ◽

Design Support System ◽

Simulation Results ◽

Twisting Angle ◽

Motion Design

In this paper, a new thermal actuator for micromirror control with very low operating voltage is described. The actuator consists of three straight polysilicon cantilever arms and a polysilicon winding arm that is inherently twisted due to stress-induced bending. Controlling heat generating positions in those arms, the actuator shows both torsional and vertical motions. Mechanical-electro-thermal FEM simulation results show that the actuator has more than a 1.11 degree twisting angle and a 2.31 μm vertical displacement. In order to enhance torsional motion, design optimization is carried out by using a response surface method called the statistical design support system. After optimization, the total twisting angle improves to 2.05 degrees which is enough to actuate micromirrors for optical beam adjusting, switching and attenuating.

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Fem Simulation of Micro-Rotating-Structures and Their Applications in Measurement of Residual Stresses in Thin Films

MRS Proceedings ◽

10.1557/proc-505-21 ◽

1997 ◽

Vol 505 ◽

Cited By ~ 5

Author(s):

Xin Zhang ◽

Tong-Yi Zhang ◽

Yitshak Zohar

Keyword(s):

Thin Films ◽

Residual Stresses ◽

Fem Simulation ◽

Sensitivity Factor ◽

Local Measurement ◽

Micro Structure ◽

Micro Raman Spectroscopy ◽

Before And After ◽

Polysilicon Films ◽

Simulation Results

ABSTRACTFEM simulation of micro-rotating-structures was performed for local measurement of residual stresses in thin films. A sensitivity factor is introduced, studied and tabulated from the simulation results. The residual stress can be evaluated from the rotating deflection, the lengths of rotating and fixed beams, and the sensitivity factor. The micro-structure technique was applied to measure residual stresses in both silicon nitride and polysilicon thin films, before and after rapid thermal annealing (RTA), and further confirmed by wafer curvature method. Residual stresses in polysilicon films at different RTA stages were also characterized by micro-Raman spectroscopy (MRS). The experimental results indicate that micro-rotating-structures indeed have the ability to measure spatially and locally residual stresses in MEMS thin films with appropriate sensitivities.

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Effect of the Load Path on Formability of T-Shaped Tube Hydroforming

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.101-102.962 ◽

2011 ◽

Vol 101-102 ◽

pp. 962-965 ◽

Cited By ~ 1

Author(s):

Wen Liu ◽

Ji Qiang Li ◽

Bin Bin Chen ◽

Zhi Xin Jia

Keyword(s):

Tube Hydroforming ◽

Fem Simulation ◽

Evaluation Index ◽

Load Path ◽

Line Load ◽

Evaluation Indexes ◽

Shaped Tube ◽

Simulation Results

Based on the analysis of now available evaluation indexes to estimate the formability of T-shaped tube hydroforming, an aggregative indicator is proposed. The effect of load path on the formability of T-shaped tube is discussed by FEM simulation, and validity of the evaluation index and simulations are proved by experiment. Results show that with the broken line load path of 0-35-35-60, the value of aggregative indicator is the greatest and the formability is the best. The optional parameters are testified by experiment and the results are in agreement with the FEM simulation results.

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A Multibody Dynamics Approach to Friction Wedge Modeling for Freight Train Suspensions

ASME/IEEE 2007 Joint Rail Conference and Internal Combustion Engine Division Spring Technical Conference ◽

10.1115/jrc/ice2007-40050 ◽

2007 ◽

Cited By ~ 3

Author(s):

J. Steets ◽

B. J. Chan ◽

C. Sandu

Keyword(s):

Degrees Of Freedom ◽

Vertical Axis ◽

Vertical Displacement ◽

Unilateral Contact ◽

Transient Dynamics ◽

Normal Forces ◽

Body Dynamics ◽

Modeling Software ◽

Simulation Results ◽

Multi Body

This paper presents an effort to use multi-body dynamics with unilateral contact to model the friction wedge interaction with the bolster and the side frame. The new friction wedge model is a 3D, dynamic, stand-alone model of a bolster-friction wedge-side frame assembly. It allows the wedge four degrees of freedom: vertical displacement, longitudinal (between the bolster and the side frame) displacement, toe-in and toe-out, and yaw (rotation about the vertical axis). The dedicated train modeling software NUCARS® has been used to run simulations with similar inputs and to compare — when possible — the results with those obtained from the new stand-alone MATLAB friction wedge model. The stand-alone model shows improvement in capturing the transient dynamics of the wedge better. Also, it can predict not only normal forces going into the frame and bolster, but also use the associated moments to enhance model behavior. Significant simulation results are presented and the main differences between the current NUCARS® model and the new stand-alone MATLAB models are highlighted.

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The Influence of Rotor Bar Wear of Impact Crusher on Impact Effect

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.42.135 ◽

2010 ◽

Vol 42 ◽

pp. 135-138 ◽

Cited By ~ 1

Author(s):

Shu Juan Cao ◽

Hai Zhang ◽

Sen Li

Keyword(s):

Impact Force ◽

Fem Simulation ◽

Data Simulation ◽

Simulation Data ◽

Impact Effect ◽

Large Influence ◽

Initial Stage ◽

Simulation Results ◽

Experiment And Simulation

The influence of the wear of the rotor bar on its impact effect was investigated with FEM simulation. The effectiveness of FEM simulation on the research of impact force was verified through the comparison of experiment and simulation data. Simulation results showed that the wear of rotor bar has not so large influence on impact force. In its initial stage, the bar is worn easily, and the wear becomes slow with the wear increasing.

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Material Characterization for FEM Simulation of Sheet Metal Stamping Processes

Advances in Mechanical Engineering ◽

10.1155/2014/167147 ◽

2014 ◽

Vol 6 ◽

pp. 167147 ◽

Cited By ~ 1

Author(s):

Alejandro Quesada ◽

Antonio Gauchia ◽

Carolina Álvarez-Caldas ◽

José Luis San Román

Keyword(s):

Sheet Metal ◽

Manufacturing Industry ◽

Fem Simulation ◽

Main Tool ◽

Material Model ◽

Experimental Results ◽

Simulation Tools ◽

Sheet Metal Parts ◽

Simulation Results ◽

Parameter Values

Sheet metal forming is an important technology in manufacturing, especially in the automotive industry. Today, engineering simulation tools based on the finite elements method are employed regularly in the design of stamping dies for sheet metal parts. However, a bad material model choice or the use of nonaccurate enough parameters can lead to imprecise simulation results. This work uses ANSYS LS-DYNA software to analyze several material models and the influence of their parameter values in FEM simulation results. The main tool to solve these problems is an application designed to assist die stamp designers. The program allows a procedure to be defined to obtain the values of the properties of an unknown material, which combines finite element simulations with real experimental results. Results obtained for the simulation of a real automotive part are analyzed and compared with the real experimental results. Parameters involved in each material model have been identified, and their influence in final results has been quantified. This is very useful to fit material properties in other simulations. This paper fulfils an identified need in the manufacturing industry. In fact, the proposed application is currently being used by a manufacturer of automotive components.

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Comparison of Offset and Wiping Z-Die Designs for Precision Z-Bent Part Fabrication

Journal of Manufacturing Science and Engineering ◽

10.1115/1.4038727 ◽

2018 ◽

Vol 140 (2) ◽

Cited By ~ 1

Author(s):

Sutasn Thipprakmas ◽

Pakkawat Komolruji ◽

Wiriyakorn Phanitwong

Keyword(s):

Fem Simulation ◽

The Finite Element Method ◽

Spring Back ◽

Bend Radius ◽

Dimensional Precision ◽

Bending Process ◽

Simulation Results ◽

Bend Angles ◽

Selection Of ◽

Good Agreement

In recent years, the requirements for high dimensional precision on Z-bent shaped parts have become increasingly stringent. To attain these requirements, the suitable selection of the Z-die bending type has to be considered much more strictly. In this research, two types of Z-bending processes, offset Z-die bending and wiping Z-die bending, were investigated using the finite element method (FEM) to identify the spring-back characteristics and dimensions of Z-bent shaped parts. In the case of offset Z-die bending, the spring-back characteristics on both bend angles were similar. In contrast, in the case of wiping Z-bending, the spring-back characteristics on both bend angles were different. In addition, the dimensions of the Z-bent shaped parts were investigated. It was found, in the case of wiping Z-bending, that web thinning was generated and the outer bend radius was out of tolerance. To validate the FEM simulation results, experiments were carried out. The FEM simulation results showed good agreement with the experimental results in terms of the bend angles and the overall geometry of the Z-bent shaped parts. To achieve precise Z-bent shaped parts, the suitable selection of Z-die bending type in the Z-die bending process is very important.

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The Influence of Residual Stress on the Machining Deformation

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.426.172 ◽

2012 ◽

Vol 426 ◽

pp. 172-176

Author(s):

Hun Guo

Keyword(s):

Residual Stress ◽

Finite Element ◽

Finite Element Model ◽

Simulation Model ◽

Elasticity Theory ◽

Initial Stress ◽

Fem Simulation ◽

Element Model ◽

Fem Model ◽

Simulation Results

The key problems in 2D FEM simulation such as the establishment of finite element model, the initial stress loading, the distortion appraisal are solved and 2D FEM simulation model is built to analyze the milling distortion caused by the residual stress. The FEM model is verified by the elasticity theory. Some machining cases are simulated by using of the FEM model. The machining distortion caused by residual stress are analyzed and summarized using the simulation results.

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Application of Cascaded Multilevel Inverter for High Voltage Grid-Connected PV System

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1092-1093.17 ◽

2015 ◽

Vol 1092-1093 ◽

pp. 17-21

Author(s):

Yi Dan Li ◽

Du Ting Wang ◽

Hong Ming Kang ◽

Hong Fang Ru

Keyword(s):

Multilevel Inverter ◽

Operating Voltage ◽

Generation System ◽

Pv System ◽

Photovoltaic Generation ◽

In Series ◽

Simulation Results ◽

High Level ◽

Pv Generation ◽

Cascaded Multilevel Inverter

The cascaded multilevel inverter may be the best topology to satisfy continuously increasing capacity and scale of grid-connected photovoltaic generation system due to its modularized circuit layout and sufficiently high operating voltage without devices in series. The operating principle of the cascaded multilevel inverter is presented. The control strategy of carrier phase shift PWM is proposed and discussed in detail. A grid-connected photovoltaic (PV) generation system based on a seven level cascaded inverter is provided. Simulation model of a seven level cascaded inverter with phase shifted PWM is built in Simulink environment and simulation results verify that the cascaded multilevel inverter can output high level voltage without devices in series, reduce harmonics, and output high quality waveforms.

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Estimation of Micro-Formability and FEM Simulation of Micro-Forming Process of a Zr-Based Bulk Metallic Glass

Materials Science Forum ◽

10.4028/www.scientific.net/msf.539-543.2129 ◽

2007 ◽

Vol 539-543 ◽

pp. 2129-2134

Author(s):

Young Sang Na ◽

S.G. Kang ◽

K.Y. Park ◽

Jong Hoon Lee

Keyword(s):

Metallic Glass ◽

Bulk Metallic Glass ◽

Fem Simulation ◽

Supercooled Liquid ◽

Supercooled Liquid Region ◽

Liquid Region ◽

Micro Forming ◽

Forming Process ◽

Rf Values ◽

Simulation Results

Micro-forming is considered to be a suited technology to manufacture very small metallic parts (several μm~mm). Zr-based bulk metallic glass, Zr62Cu17Ni13Al8, has been expected to be a promising metallic material for micro-forming process due to their isotropy, low flow stress in a wide supercooled liquid region and good stability of amorphous matrix. Therefore, one can expect that micro-forming of Zr62Cu17Ni13Al8 might be feasible at a relatively low stress in the supercooled liquid state without any crystallization during hot deformation. In this study, micro-formability of Zr62Cu17Ni13Al8 bulk metallic glass was investigated for micro-forging of U-shape pattern. Microformability was estimated by comparing Rf values (=Af/Ag), where Ag is corss-sectional area of U groove, and Af the filled area by material. Micro-forging process was also simulated and analyzed by applying the finite element method. The micro-formability of Zr62Cu17Ni13Al8 was increased with increasing load and time in the temperature range of the supercooled liquid state. In spite of the similar trend in the variations of Rf values, FEM simulation results showed much higher Rf values than the experimental Rf values. This disagreement was analyzed based on the stress overshoot phenomena of bulk metallic glasses in the supercooled liquid region. FEM simulation of the microstamping process was applicable for the optimization of micro-forming process by carefully interpreting the simulation results.

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