Electrothermal Characterization of Doped-Si Heated Microcantilevers Under Periodic Heating Operation

2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Sina Hamian ◽  
Andrew M. Gauffreau ◽  
Timothy Walsh ◽  
Jungchul Lee ◽  
Keunhan Park
Keyword(s):  
Microelectromechanical Systems ◽  
Transfer Functions ◽  
Design Parameters ◽  
Periodic Heating ◽  
Element Analysis ◽  
Full Spectrum ◽  
Frequency Dependent ◽  
Thermal Transfer ◽  
Fea Model

This paper reports the frequency-dependent electrothermal behaviors of a freestanding doped-silicon heated microcantilever probe operating under periodic (ac) Joule heating. We conducted a frequency-domain finite-element analysis (FEA) and compared the steady periodic solution with 3ω experiment results. The computed thermal transfer function of the cantilever accurately predicts the ac electrothermal behaviors over a full spectrum of operational frequencies, which could not be accomplished with the 1D approximation. In addition, the thermal transfer functions of the cantilever in vacuum and in air were compared, through which the frequency-dependent heat transfer coefficient of the air was quantified. With the developed FEA model, design parameters of the cantilever (i.e., the size and the constriction width of the cantilever heater) and their effects on the ac electrothermal behaviors were carefully investigated. Although this work focused on doped-Si heated microcantilever probes, the developed FEA model can be applied for the ac electrothermal analysis of general microelectromechanical systems.

Characterization of Laser Processed Sub-Millimeter Lap Joints Between Copper and Aluminum Under Tensile Load

2010 ◽  
Author(s):  
A. Mian ◽  
M. Hailat ◽  
G. Newaz ◽  
R. Patwa ◽  
H. Herfurth
Keyword(s):  
Stress Distribution ◽  
Tensile Load ◽  
Lap Joints ◽  
Filler Materials ◽  
Element Analysis ◽  
Full Field ◽  
Fea Model ◽  
Lap Shear ◽  
Copper Aluminum

This paper presents the results of laser joined copper-aluminum lap shear samples without filler materials using an IPG 500W SM fiber laser. The length of the processed laser joint was about 20 mm and the width was about 200 μm. Laser-joined samples were tested under tensile loading to determine joint strengths. In addition, finite element analysis (FEA) was conducted to understand the stress distribution within the bond area under such loading. The FEA model provides a full-field stress distribution in and around the joint that cause eventual failure. We are still working on the topic, and more data will be published soon.

scholarly journals A comparison between hybrid method technique and transfer matrix method for design optimization of vehicle muffler

2021 ◽  
Vol 49 (2) ◽  
pp. 494-500
Author(s):  
Barhm Mohamad ◽  
Jalics Karoly ◽  
Andrei Zelentsov ◽  
Salah Amroune
Keyword(s):  
Transmission Loss ◽  
Complex Structure ◽  
Design Parameters ◽  
Element Analysis ◽  
Vehicle Noise ◽  
Race Car ◽  
Fea Model ◽  
Important Approach ◽  
Machine Analysis ◽  
Perforated Pipe

Hybrid mufflers are now commonly equipped to decrease vehicle noise and are a crucial tool for regulation of the acoustic system. In order to ensure optimum engine efficiency, the system is intended to dump the strength of the acoustic pulses generated from the engine, and the back pressure created by these systems must be held to a minimum. Typically, modern mufflers have a complex structure of chambers and flow paths. There are a number of mechanisms for sound dampening that operate to silence the sound flowing through a muffler and piping device. This research introduces an important approach to optimize the transmission loss of hybrid muffler Formula student race car (FS) by using both experimental and analytical methods. For this analysis, two methods of calculation were chosen. The muffler has a complex partition located within the muffler chamber, which is a perforated pipe. For the creation of the Finite Element Analysis (FEA) model in AVL BOOST solver and another commercial advanced design software, the muffler CAD file was developed. Experimental measurements using a two-load method validated the FEA model. Reliable tests were conducted to verify the design parameters and optimize the muffler's transmission loss (TL) after the model was checked. The findings of experimental and machine analysis are included in the paper. For different measurement methods, recommendations are made for achieving optimum transmission loss curves.

scholarly journals A hybrid method technique for design and optimization of Formula race car exhaust muffler

2020 ◽  
Vol 11 (2) ◽  
pp. 174-180
Author(s):  
Barhm Mohamad ◽  
Jalics Karoly ◽  
Andrei Zelentsov ◽  
Salah Amroune
Keyword(s):  
Computer Aided Design ◽  
Cfd Simulation ◽  
Fluid Dynamic ◽  
Design Parameters ◽  
Piping System ◽  
Element Analysis ◽  
Software Analysis ◽  
Race Car ◽  
Fea Model ◽  
Car Exhaust

AbstractIn this work a multilevel Computational Fluid Dynamics (CFD) analysis has been applied for the design of a Formula race car exhaust muffler with improved characteristics of sound pressure level (SPL) and fluid dynamic response. The approaches developed and applied for the optimization process range from the 1D to fully 3D CFD simulation, exploring hybrid approaches based on the integration of a 1D model with 3D tools. Modern mufflers typically have a complex system of chambers and flow paths. There are a variety of sound damping and absorbing mechanisms working to quiet the sound flowing through a muffler and piping system. Two calculation methods were selected for this study. The muffler has a complex inner structure containing perforated pipe and fiber material. Computer-aided design (CAD) file of the muffler was established for developing Finite Element Analysis (FEA) model in AVL BOOST v2017 and another commercial advanced design software (SolidWorks 2017). FEA model was made to monitor the flow properties, pressure and velocity. After the model was verified, sensitivity studies of design parameters were performed to optimize the SPL of the muffler. The software analysis results are included in the paper. Recommendations are made for obtaining smoother SPL curves for various measurement methods.

scholarly journals Sensitivity Analysis of Single-Drive, 3-axis MEMS Gyroscope Using COMSOL Multiphysics

Micromachines ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1030
Author(s):  
Hussamud Din ◽  
Faisal Iqbal ◽  
Byeungleul Lee
Keyword(s):  
Microelectromechanical Systems ◽  
Angular Rate ◽  
Mode Analysis ◽  
Comsol Multiphysics ◽  
Mechanical Sensitivity ◽  
Drive Mode ◽  
Element Analysis ◽  
Mems Gyroscope ◽  
Fea Model ◽  
Mode Split

In this paper, a COMSOL Multiphysics-based methodology is presented for evaluation of the microelectromechanical systems (MEMS) gyroscope. The established finite element analysis (FEA) model was successfully validated through a comparison with analytical and Matlab/Simulink analysis results. A simplified single-drive, 3-axis MEMS gyroscope was analyzed using a mode split approach, having a drive resonant frequency of 24,918 Hz, with the x-sense, y-sense, and z-sense being 25,625, 25,886, and 25,806 Hz, respectively. Drive-mode analysis was carried out and a maximum drive-displacement of 4.0 μm was computed for a 0.378 μN harmonic drive force. Mechanical sensitivity was computed at 2000 degrees per second (dps) input angular rate while the scale factor for roll, pitch, and yaw was computed to be 0.014, 0.011, and 0.013 nm/dps, respectively.

Design Methodology for Microelectromechanical Systems. Case Study: Torsional Scanner Mirror

2006 ◽  
Vol 129 (10) ◽  
pp. 1023-1030 ◽  
Author(s):  
Faik Can Meral ◽  
Ipek Basdogan
Keyword(s):  
State Space ◽  
Microelectromechanical Systems ◽  
Transfer Functions ◽  
State Space Model ◽  
The State ◽  
Mode Shapes ◽  
Design Parameters ◽  
Space Representation ◽  
Disturbance Analysis ◽  
Disturbance Torque

Future optical microsystems, such as microelectromechanical system (MEMS) scanners and micromirrors, will extend the resolution and sensitivity offered by their predecessors. These systems face the challenge of achieving nanometer precision subjected to various disturbances. Predicting the performance of such systems early in the design process can significantly impact the design cost and also improve the quality of the design. Our approach aims to predict the performance of such systems under various disturbance sources and develop a generalized design approach for MEMS structures. In this study, we used ANSYS for modeling and dynamic analysis of a torsional MEMS scanner mirror. ANSYS modal analysis results, which are eigenvalues (natural frequencies) and eigenvectors (mode shapes), are used to obtain the state-space representation of the mirror. The state-space model of the scanner mirror was reduced using various reduction techniques to eliminate the states that are insignificant for the transfer functions of interest. The results of these techniques were compared to obtain the best approach to obtain a lower order model that still contains all the relevant dynamics of the original model. After the model size is reduced significantly, a disturbance analysis is performed using Lyapunov approach to obtain root-mean-square values of the mirror rotation angle under the effect of a disturbance torque. The magnitude levels of the disturbance torque are obtained using an experimental procedure. The disturbance analysis framework is combined with the sensitivity analysis to determine the critical design parameters for optimizing the system performance.

scholarly journals Fabrication and Characterization of High-Sensitivity Underwater Acoustic Multimedia Communication Devices with Thick Composite PZT Films

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Jeng-Cheng Liu ◽  
Yuang-Tung Cheng ◽  
Sheng-Yun Ho ◽  
Hsien-Sen Hung ◽  
Shun-Hsyung Chang
Keyword(s):  
High Performance ◽  
Microelectromechanical Systems ◽  
High Sensitivity ◽  
Water Tank ◽  
Epitaxial Thin Films ◽  
Element Analysis ◽  
Pzt Films ◽  
Communication Devices ◽  
Mems Process

This paper presents a high-sensitivity hydrophone fabricated with a Microelectromechanical Systems (MEMS) process using epitaxial thin films grown on silicon wafers. The evaluated resonant frequency was calculated through finite-element analysis (FEA). The hydrophone was designed, fabricated, and characterized by different measurements performed in a water tank, by using a pulsed sound technique with a sensitivity of −190 dB ± 2 dB for frequencies in the range 50–500 Hz. These results indicate the high-performance miniaturized acoustic devices, which can impact a variety of technological applications.

Engineering Applications of Satellite Structural Optimization Utilizing ANSYS/CATIA

2011 ◽  
Vol 110-116 ◽  
pp. 1567-1575
Author(s):  
Jia Mao ◽  
Wei Hua Zhang
Keyword(s):  
Optimization Design ◽  
Parametric Design ◽  
Reference Value ◽  
Optimization Method ◽  
Design Parameters ◽  
Element Analysis ◽  
Fea Model ◽  
Satellite Platform ◽  
Weight Design ◽  
Work Done

A structured frame for the design optimization problem of satellite platform structure was established through the definition, flow and modification research of design parameters in the ANSYS/CATIA system. Problems with creating complex satellite structure FEA (Finite Element Analysis) models were discussed, including the idealization of real structure, as well as embedment of APDL (ANSYS Parametric Design Language) programme developed specially for the pre-processing and post-processing of FEA model. The optimization model was established under structural design requirements, and a graded optimization method was applied for calculation. Light-weight design schemes for two satellite platform structure were obtained through the subsequently optimization implemented using approaches put forward previously. The optimization design problems of two satellite platform structure were settled well, and work done in this paper provides certain reference value for optimization of other spacecraft structures.

Power Packaging Thermal and Stress Model for Quick Parametric Analyses

2017 ◽  
Author(s):  
L. M. Boteler ◽  
S. M. Miner
Keyword(s):  
Thermal Stresses ◽  
Thermal Analyses ◽  
Computational Time ◽  
Design Parameters ◽  
Power Module ◽  
Element Analysis ◽  
Resistor Network ◽  
Fea Model ◽  
Wide Range ◽  
Packaging Structure

This work presents an easy to use approach to quickly estimate the device temperatures and thermal stresses in a generic high power module. A low order model was developed in MATLAB using a combination of numerical-analytical approach and a 3D nodal resistor network to calculate device temperatures and thermal stresses. The model assumes a heat flux generated at the top of each device which is dissipated through the packaging structure and removed by convection. The temperature distribution is used to calculate thermal stresses throughout the package. This method eliminates computer aided drawings (CAD) in favor of numerical parameters that can be easily and quickly varied over a wide range. The resistor network solves quickly in MATLAB, enabling fast, iterative thermal analyses and design through parametric studies of the chip dimensions, number of chips, chip layout, material types, cooling solutions, etc. The model is adaptable to any number of devices and board layers. The MATLAB model reduced the computational time by 97% compared to an equivalent SOLIDWORKS finite element analysis (FEA) model and that does not include the time required to generate the CAD model and verify mesh convergence and mesh independence. Temperatures from the network model were within 5°C and stresses were within 30% of the values obtained from the FEA model. The ability to quickly assess the thermal and stress effects of a wide variety of power module design parameters during the initial design process, without the complexity of a full FEA analysis, with reasonable results can significantly improve the final module.

Improvements to the ASME B31.8 Dent Strain Equations

2018 ◽  
Vol 140 (4) ◽  
Author(s):  
Chike Okoloekwe ◽  
Nikko Aranas ◽  
Muntaseer Kainat ◽  
Doug Langer ◽  
Sherif Hassanien ◽  
...  
Keyword(s):  
Strain Distribution ◽  
Oil And Gas ◽  
Three Dimensional ◽  
Element Analysis ◽  
Fea Model ◽  
Global View ◽  
Current Implementation ◽  
Gas Products ◽  
External Forces

Pipelines used to transport oil and gas products are often subjected to external forces during its construction or operation, which can result in the formation of dents in the pipe. Various pipeline codes have stipulations on how a dent's severity can be ascertained in order to prioritize repairs. The most prominent being the depth-based criterion, which determines the severity of a dent by its depth. The depth-based criterion fails to consider the fact that the geometry of the dent can result in high strain concentration and eventually lead to integrity issues at the dented region. Alternatively, the strains associated with the dent can be an indicator of the dent's severity. Nonmandatory codified equations are available for evaluating the strains at the dented region of the pipe. The current implementation of these equations might fail to capture the strains that are not aligned with the most severe deformation profile of the dent and as such a global view of the strain distribution of the dented profile would be more informative as per the localized strain distribution. The study presented herein is the implementation of ASME B31.8 formulations together with the suggested modifications to evaluate the three-dimensional (3D) strain state of the dented pipe. The strain distributions obtained are compared against the strains predicted by finite element analysis (FEA) model. The correlation in the predicted strains indicates the possibility of the rapid and concise strain based characterization of dented pipes with the proposed technique.

Tire Bead Overheating in Urban Buses and Trucks Using Drum Brake Systems

1998 ◽  
Vol 26 (1) ◽  
pp. 51-62
Author(s):  
A. L. A. Costa ◽  
M. Natalini ◽  
M. F. Inglese ◽  
O. A. M. Xavier
Keyword(s):  
Heat Transfer ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Thermal Energy ◽  
Structural Integrity ◽  
Experimental Temperature ◽  
Temperature Profiles ◽  
Element Analysis ◽  
Drum Brake ◽  
Fea Model

Abstract Because the structural integrity of brake systems and tires can be related to the temperature, this work proposes a transient heat transfer finite element analysis (FEA) model to study the overheating in drum brake systems used in trucks and urban buses. To understand the mechanics of overheating, some constructive variants have been modeled regarding the assemblage: brake, rims, and tires. The model simultaneously studies the thermal energy generated by brakes and tires and how the heat is transferred and dissipated by conduction, convection, and radiation. The simulated FEA data and the experimental temperature profiles measured with thermocouples have been compared giving good correlation.

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