scholarly journals A Multi-Fidelity Model for Simulations and Sensitivity Analysis of Piezoelectric Inkjet Printheads

Micromachines ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1038
Author(s):  
Vinh-Tan Nguyen ◽  
Jason Yu Chuan Leong ◽  
Satoshi Watanabe ◽  
Toshimitsu Morooka ◽  
Takayuki Shimizu
Keyword(s):  
Sensitivity Analysis ◽  
Three Dimensional ◽  
Element Model ◽  
Geometrical Parameters ◽  
Generation Process ◽  
Mechanical Coupling ◽  
Design Variables ◽  
Computational Structural Mechanics ◽  
Lumped Element Model ◽  
Inkjet Printhead

The ink drop generation process in piezoelectric droplet-on-demand devices is a complex multiphysics process. A fully resolved simulation of such a system involves a coupled fluid–structure interaction approach employing both computational fluid dynamics (CFD) and computational structural mechanics (CSM) models; thus, it is computationally expensive for engineering design and analysis. In this work, a simplified lumped element model (LEM) is proposed for the simulation of piezoelectric inkjet printheads using the analogy of equivalent electrical circuits. The model’s parameters are computed from three-dimensional fluid and structural simulations, taking into account the detailed geometrical features of the inkjet printhead. Inherently, this multifidelity LEM approach is much faster in simulations of the whole inkjet printhead, while it ably captures fundamental electro-mechanical coupling effects. The approach is validated with experimental data for an existing commercial inkjet printhead with good agreement in droplet speed prediction and frequency responses. The sensitivity analysis of droplet generation conducted for the variation of ink channel geometrical parameters shows the importance of different design variables on the performance of inkjet printheads. It further illustrates the effectiveness of the proposed approach in practical engineering usage.

Modeling and Optimizing Industrial Inkjet Printhead for Printable Electronics Fabrication

2015 ◽  
Vol 748 ◽  
pp. 15-19
Author(s):  
Lian Bo Ma ◽  
Mao Wei He ◽  
Kun Yuan Hu ◽  
Yun Long Zhu
Keyword(s):  
Experimental Studies ◽  
Element Model ◽  
Printable Electronics ◽  
Lumped Element ◽  
Drop On Demand ◽  
Printing Quality ◽  
Lumped Element Model ◽  
Driving Waveform ◽  
Nonlinear Behaviors ◽  
Inkjet Printhead

The most significant issues in printable electronics fabrication are the printing quality and efficiency delivered by drop-on-demand (DOD) industrial inkjet printhead. Aiming to characterize the nonlinear behaviors of piezoelectric inkjet printhead, the dynamic lumped element model (DLEM) is proposed to cast the original LEM into a time-varying and nonlinear fashion. At the same time , the PSO-based optimization for paramenters is incorporated in DLEM. Due to new characteristics, DLEM can accurately simulate the inkjet-printed nanosilver droplet formation process and effectively predicate optimal combinations of high-frequency driving waveform with high printing quality. From extensive experimental studies, the effectiveness and efficiency of the proposed DLEM is validated.

Three-dimensional optimum design of the cooling lines of injection moulds based on boundary element design sensitivity analysis

2002 ◽  
Vol 216 (7) ◽  
pp. 1067-1071 ◽  
Author(s):  
H Zhou ◽  
D Li ◽  
S Cui
Keyword(s):  
Sensitivity Analysis ◽  
Objective Function ◽  
Boundary Element ◽  
Optimum Design ◽  
Three Dimensional ◽  
Design Sensitivity ◽  
Boundary Integral ◽  
Optimization Techniques ◽  
Design Sensitivity Analysis ◽  
Design Variables

A three-dimensional numerical simulation using the boundary element method is proposed, which can predict the cavity temperature distributions in the cooling stage of injection moulding. Then, choosing the radii and positions of cooling lines as design variables, the boundary integral sensitivity formulations are deduced. For the optimum design of cooling lines, the squared difference between the objective temperature and the temperature of the cavity is taken as the objective function. Based on the optimization techniques with design sensitivity analysis, an iterative algorithm to reach the minimum value of the objective function is introduced, which leads to the optimum design of cooling lines at the same time.

scholarly journals Thermo-mechanical coupling–based finite element analysis of the load distribution of planetary roller screw mechanism

2018 ◽  
Vol 10 (6) ◽  
pp. 168781401877525 ◽  
Author(s):  
Shangjun Ma ◽  
Chenhui Zhang ◽  
Tao Zhang ◽  
Geng Liu ◽  
Shumin Liu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Load Distribution ◽  
Three Dimensional ◽  
Theoretical Models ◽  
Element Model ◽  
Element Analysis ◽  
Mechanical Coupling ◽  
Roller Screw ◽  
Screw Mechanism

In this article, 3D or three-dimensional finite element analysis is used to simulate and evaluate the load distribution characteristics of a planetary roller screw mechanism under thermo-mechanical coupling. The finite element model takes into account the installation modes of the planetary roller screw mechanism, which is verified by comparison with theoretical models for a certain load magnitude in four installation modes. In addition, the effects of the installation mode, load magnitude, and temperature condition on the load distribution are also systematically analyzed. The numerical results reveal a phenomenon of threads separating from the meshing, which indicates that the influence of thermo-mechanical coupling on the load distribution cannot be ignored. Furthermore, the influence of the installation mode on the screw–roller interface is larger than that on the nut–roller interface. Compared with the screw–roller interface, the temperature difference is one of the main conditions affecting the load distribution of the planetary roller screw mechanism and has a significant effect on the nut–roller interface. In addition, the influences of the screw rotational speed and the load magnitude on the load distribution on the screw–roller interface are larger than those on the nut–roller interface for the four installation modes.

scholarly journals Applying Virtual Reality Techniques to Sensitivity-Based Structural Shape Design

1998 ◽  
Vol 120 (4) ◽  
pp. 612-619 ◽  
Author(s):  
T. P. Yeh ◽  
J. M. Vance
Keyword(s):  
Sensitivity Analysis ◽  
Virtual Reality ◽  
Three Dimensional ◽  
Element Model ◽  
Free Form ◽  
Shape Design ◽  
Connecting Rod ◽  
Structural Shape ◽  
Initial Application ◽  
Free Form Deformation

Virtual reality (VR) provides a design space consisting of three-dimensional computer images where participants can interact with these images using natural human motions in real time. In the field of engineering design, prototyping and design verification have provided the initial application areas for VR. The research presented in this paper takes the scenario one step further by incorporating free-form deformation techniques and sensitivity analysis into the virtual world such that the designer can easily implement analysis-based shape design of a structural system where stress considerations are important. NURBS-based free-form deformation (NFFD) methods and direct manipulation techniques are used as the interface between the VR interaction and the finite element model. Sensitivity analysis is used to allow the designer to change the design model and immediately view the effects without performing a re-analysis. An engine connecting rod is analyzed to demonstrate how virtual reality techniques can be applied to structural shape design.

Study on the Effect of Tool Geometrical Parameters on Cutting Forces Based on Finite Element Method

2013 ◽  
Vol 663 ◽  
pp. 580-585
Author(s):  
Zhi Tao Tang ◽  
Tao Yu ◽  
Li Qiang Xu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Cutting Forces ◽  
Three Dimensional ◽  
Element Model ◽  
Friction Model ◽  
Geometrical Parameters ◽  
Finite Element Software ◽  
Coulomb Friction Model ◽  
Cutting Model

Based on finite element software DEFORM-3D, a three-dimensional oblique cutting model for aerospace aluminum alloy was built. The material’s flow stress behavior was described with Johnson-Cook constitutive equation. The separation of the chips with the workpiece was realized by the combination of adaptive remeshing technique and separation criterion. The material’s failure was defined by adopting Cockcroft & Latham fracture criterion. The tool-chip friction model was the combination of a Coulomb friction model and shear (sticking) friction model. To validate the finite element model, cutting tests were conducted. The effects of tool geometrical parameters such as flank wear, cutting edge inclination and corner radius on cutting forces were analyzed by three-dimensional oblique finite element model.

Three-Dimensional Aerodynamic Optimization for Axial-Flow Compressors Based Upon the Inverse Design and the Aerodynamic Variables

2010 ◽  
Author(s):  
Liu He ◽  
Peng Shan
Keyword(s):  
Computer Aided Design ◽  
Optimization Design ◽  
Three Dimensional ◽  
Visual Sensitivity ◽  
Inverse Design ◽  
Geometrical Parameters ◽  
Optimization Strategy ◽  
Design Code ◽  
Aerodynamic Optimization ◽  
Design Variables

Integrating a genetic algorithm code with a response surface methodology code based upon the artificial neural network model, this paper develops an optimization system. By introducing a quasi-three dimensional through-flow design code and a design code of axial compressor airfoils with camber lines of arbitrary shape, and involving a three-dimensional computational fluid dynamics solver, this paper establishes a numerical aerodynamic optimization platform for the three-dimensional blades of axial compressors. The optimization in this paper mainly has four features. First, it applies the conventional inverse design method instead of the common computer aided design parameterization method to generate a three-dimensional blade. Second, it chooses aerodynamic parameters with physical meaning as optimization design variables instead of purely geometrical parameters. Third, it presents a stage-by-stage optimization strategy about the multistage turbomachinery optimization. Fourth, it introduces the visual sensitivity analysis method into optimization, which can adjust variation ranges of variables by analysing how great the variables influence the objective function. The above techniques were applied to the redesign of a single rotor row and two double-stage axial fans separately. The departure angles and work distributions in the inverse design were taken as design variables separately in optimizations of the single rotor and double-stage fans, and they were parametrically represented by means of Be´zier curves, whose parameters were used as the optimization variables in the practical operation. The three investigated examples elucidate that not only the techniques mentioned above are appropriate and effective in engineering, but also the design guidance for similar inverse design problems can be obtained from the optimization results.

Mathematical Simulation of Thermomechanics in an Impermeable Porous Medium

2020 ◽  
pp. 4-23
Author(s):  
M.V. Alekseev ◽  
N.G. Sudobin ◽  
A.A. Kuleshov ◽  
E.B. Savenkov
Keyword(s):  
Mathematical Model ◽  
Porous Medium ◽  
Chemical Reactions ◽  
Three Dimensional ◽  
Element Model ◽  
Lumped Element ◽  
The Matrix ◽  
Thermochemical Processes ◽  
Lumped Element Model ◽  
The Mathematical Model

The paper reports on mathematically simulating behaviour of a porous medium featuring isolated interstices filled with a chemically active substance by using a mathematical model of thermomechanics in the matrix and thermochemical processes inside the pores. We used three-dimensional thermomechanical equations to describe the behaviour of the medium. A lumped-element model accounting for chemical reactions and phase equilibrium describes the processes in pores. We outline the mathematical model of the medium and the respective computational algorithm. We provide parametric computation results using realistic thermophysical and thermodynamical parameters, composition of the organic substance found inside pores (products of thermal decomposition of kerogen) and chemical reactions, which show that it is necessary to employ complex, interconnected models to simulate the process class under consideration

Using Discrete Element Model to Simulate Keel-Gouging: A Sensitivity Analysis

2017 ◽  
Author(s):  
Eleanor Bailey Dudley ◽  
Lei Liu ◽  
Robert Sarracino ◽  
Rocky Taylor
Keyword(s):  
Sensitivity Analysis ◽  
Young’S Modulus ◽  
Oil And Gas ◽  
Young's Modulus ◽  
Three Dimensional ◽  
Friction Angle ◽  
Element Model ◽  
Discrete Element ◽  
Discrete Element Model ◽  
Premature Failure

A three-dimensional discrete element model is under development to simulate a number of different keel-gouge and subsea interaction scenarios. The model is being validated against controlled tests conducted in the National Research Council’s ice tank facility under the Pipeline Ice Risk and Mitigation (PIRAM) Joint Industry Project, which was led by C-CORE on behalf of a number of oil and gas companies. To investigate the influence of certain key parameters on the failure behaviour of the keel, a sensitivity analysis has been carried out. Best results were achieved when Young’s modulus of the keel was 5 MPa, the shear-to-tensile ratio of the freeze bonds was set to 1.2, the internal friction angle of the ice was 9°, the bond breakage ratio 0.8 % and Young’s modulus of the gravel 0.01 MPa. A low modulus for the gravel was needed to prevent premature failure of the keel, a consequence of the model not accounting for soil deformations. Using these parameters the model was able to accurately reproduce the loads on the soil tray during peak loading. Future developments in the model include using ‘clumps’ to give more representative ice block shapes, which will allow interlocking between ice pieces and the development of force chains.

scholarly journals Drop-on-Demand Inkjet Printhead Performance Enhancement by Dynamic Lumped Element Modeling for Printable Electronics Fabrication

2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
Maowei He ◽  
Liling Sun ◽  
Kunyuan Hu ◽  
Yunlong Zhu ◽  
Lianbo Ma ◽  
...  
Keyword(s):  
Performance Enhancement ◽  
Element Model ◽  
Printable Electronics ◽  
Lumped Element ◽  
Drop On Demand ◽  
Printing Quality ◽  
Lumped Element Model ◽  
Analytic Models ◽  
Nonlinear Behaviors ◽  
Inkjet Printhead

The major challenge in printable electronics fabrication is the print resolution and accuracy. In this paper, the dynamic lumped element model (DLEM) is proposed to directly simulate an inkjet-printed nanosilver droplet formation process and used for predictively controlling jetting characteristics. The static lumped element model (LEM) previously developed by the authors is extended to dynamic model with time-varying equivalent circuits to characterize nonlinear behaviors of piezoelectric printhead. The model is then used to investigate how performance of the piezoelectric ceramic actuator influences jetting characteristics of nanosilver ink. Finally, the proposed DLEM is applied to predict the printing quality using nanosilver ink. Experimental results show that, compared to other analytic models, the proposed DLEM has a simpler structure with the sufficient simulation and prediction accuracy.

Kelvin Test Structure Modeling of Metal-Silicide-Silicon Contacts

1998 ◽  
Vol 514 ◽  
Author(s):  
G. K. Reeves ◽  
A. S. Holland ◽  
P. W. Leech
Keyword(s):  
Current Density ◽  
Ohmic Contacts ◽  
Contact Region ◽  
Three Dimensional ◽  
Element Model ◽  
Test Structure ◽  
Specific Contact Resistance ◽  
Geometrical Parameters ◽  
Silicon Devices ◽  
Three Dimensional Finite Element

ABSTRACTLow resistance ohmic contacts for silicon devices commonly incorporate silicide materials as part of the contact. The electrical characterisation of ohmic contacts requires the use of various test structures such as the Cross Kelvin Resistor in order to determine the specific contact resistance ρc. This paper describes the results of using a three-dimensional finite element model of a Kelvin Resistor test structure in order to determine the influence of the electrical and geometrical parameters of a silicide-well on the magnitude of ρc. The same model of the test structure is further used to model the current density in the contact region. The results indicate that the presence of a silicide-well leads to reduced values of both ρc and the current density.

Sign in / Sign up

Export Citation Format

Share Document