Modeling, Design, and Simulation of N/MEMS by Integrating Finite Element, Lumped Element, and System Level Analyses

2017 ◽  
pp. 41-84
Author(s):  
Jason Vaughn Clark ◽  
Prabhakar Marepalli ◽  
Richa Bansal
Keyword(s):  
Finite Element ◽  
System Level ◽  
Lumped Element

scholarly journals Thermal and electro-thermal modeling of components and systems: A review of the research at the University of Parma

2015 ◽  
Vol 28 (3) ◽  
pp. 325-344 ◽  
Author(s):  
Roberto Menozzi ◽  
Paolo Cova ◽  
Nicola Delmonte ◽  
Francesco Giuliani ◽  
Giovanna Sozzi
Keyword(s):  
Thermal Analysis ◽  
Finite Element ◽  
Thermal Modeling ◽  
Heat Sinks ◽  
Lumped Element ◽  
Passive Devices ◽  
Information Engineering ◽  
The University ◽  
Heat Sinking ◽  
Hierarchy Of Structures

paper reviews the activity carried out at the Department of Information Engineering of the University of Parma, Italy, in the field of thermal and electro-thermal modeling of devices, device and package assemblies, circuits, and systems encompassing active boards and heat-sinking elements. This activity includes: (i) Finite-Element 3D simulation for the thermal analysis of a hierarchy of structures ranging from bare device dies to complex systems including active and passive devices, boards, metallizations, and air- and water-cooled heat-sinks, and (ii) Lumped-Element thermal or electro-thermal models of bare and packaged devices, ranging from purely empirical to strictly physics- and geometry-based.

scholarly journals Bayesian Inference of Vocal Fold Material Properties from Glottal Area Waveforms Using a 2D Finite Element Model

2019 ◽  
Vol 9 (13) ◽  
pp. 2735 ◽  
Author(s):  
Paul J. Hadwin ◽  
Mohsen Motie-Shirazi ◽  
Byron D. Erath ◽  
Sean D. Peterson
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Bayesian Estimation ◽  
Material Properties ◽  
Vocal Fold ◽  
Vocal Folds ◽  
Element Model ◽  
Lumped Element ◽  
Subglottal Pressure ◽  
Contact Pressures

Bayesian estimation has been previously demonstrated as a viable method for developing subject-specific vocal fold models from observations of the glottal area waveform. These prior efforts, however, have been restricted to lumped-element fitting models and synthetic observation data. The indirect relationship between the lumped-element parameters and physical tissue properties renders extracting the latter from the former difficult. Herein we propose a finite element fitting model, which treats the vocal folds as a viscoelastic deformable body comprised of three layers. Using the glottal area waveforms generated by self-oscillating silicone vocal folds we directly estimate the elastic moduli, density, and other material properties of the silicone folds using a Bayesian importance sampling approach. Estimated material properties agree with the “ground truth” experimental values to within 3 % for most parameters. By considering cases with varying subglottal pressure and medial compression we demonstrate that the finite element model coupled with Bayesian estimation is sufficiently sensitive to distinguish between experimental configurations. Additional information not available experimentally, namely, contact pressures, are extracted from the developed finite element models. The contact pressures are found to increase with medial compression and subglottal pressure, in agreement with expectation.

A Frequency Domain Finite Element Approach for Three-Dimensional Gear Dynamics

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Christopher G. Cooley ◽  
Robert G. Parker ◽  
Sandeep M. Vijayakar
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Frequency Domain ◽  
Dynamic Models ◽  
Three Dimensional ◽  
Static Solution ◽  
System Level ◽  
Element Formulation ◽  
Lumped Parameter ◽  
Element Approach

A finite element formulation for the dynamic response of gear pairs is proposed. Following an established approach in lumped parameter gear dynamic models, the static solution is used as the excitation in a frequency domain solution of the finite element vibration model. The nonlinear finite element/contact mechanics formulation provides an accurate calculation of the static solution and average mesh stiffness that are used in the dynamic simulation. The frequency domain finite element calculation of dynamic response compares well with numerically integrated (time domain) finite element dynamic results and previously published experimental results. Simulation time with the proposed formulation is two orders of magnitude lower than numerically integrated dynamic results. This formulation admits system level dynamic gearbox response, which may include multiple gear meshes, flexible shafts, rolling element bearings, housing structures, and other deformable components.

Modeling Melting Solder in System-in-Package Assembly

2005 ◽  
Author(s):  
J. F. Zhao ◽  
J. F. Wang ◽  
C. Yang
Keyword(s):  
Finite Element ◽  
Stress Field ◽  
Solder Joint ◽  
Printed Circuit Boards ◽  
Element Model ◽  
System Level ◽  
Electrical Performance ◽  
Superposition Method ◽  
Circuit Boards ◽  
Passive Components

System-in-package (SiP) technologies typically demand an increasing number of passive components assembled into a single package to achieve system level electrical performance. Traditionally, these passive components and their assembly technologies are designed for printed circuit boards and are now integrated at the package level. However, problems may arise when solder joints are used as interconnects between the passive components and the substrate in SiP system. The solder joint may melt during the surface mounting process. Since the size of the solder joint is comparable to that of the passive components, the melting may significantly alter the stress field in the package. Consequent failure may occur if the interconnect structure is not properly designed. It is a challenge to simulate solder melting with commercial finite element codes. In this paper, the interaction between the melting solder and the surrounding structures is investigated. The stress superposition method is used in the finite element model, in which the melting solder is removed from the package and a void with identical geometry was analyzed in its place. The overall stress field is the superposition of the stress field due to temperature change and the stress field caused by the uniform pressure acting on the void surface. This method greatly simplifies the mechanical modeling.

Probabilistic Finite-Element Analyses on Turbine Blades

2009 ◽  
Author(s):  
Thomas Weiss ◽  
Matthias Voigt ◽  
Hartmut Schlums ◽  
Roland Mu¨cke ◽  
Karl-Helmut Becker ◽  
...  
Keyword(s):  
Finite Element ◽  
Turbine Blade ◽  
Gas Turbines ◽  
Numerical Models ◽  
System Level ◽  
Structural Behavior ◽  
Design Parameters ◽  
Innovative Technology ◽  
Finite Element Analyses ◽  
Operation Conditions

Further progress in the development of modern gas turbines for aircraft engines and electric power stations requires both continuous optimization on component and system level as well as the use of new and innovative technology. Thereby, the design is often pushed closer to the physical limits, which demands an outstanding understanding and predictability of the structural behavior under different design and off-design conditions. Due to the considerable costs of real component testing, the knowledge on structural behavior and failure mechanisms of gas turbine components is often gained from validated numerical models. To obtain a realistic computational image of reality, the uncertainties inherent in the design, the material properties, the loading and the operation conditions have to be considered in the modeling process. The effect of variations in key input design parameters on critical results such as the predicted component life can be evaluated on the basis of probabilistic analyses. The paper addresses first general aspects of applying probabilistic Finite-Element analyses in the turbine blade design process. Then, probabilistic design methods are applied to investigate the lifetime of a single crystal (SX) turbine blade submodel. Thereby, variations in three SX orientations as well as different load positions and variations in the creep properties are investigated by Monte-Carlo-Simulation (MCS) techniques.

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