Design Method to Achieve High Frequency Stability of Electrostatically Actuated Doubly-Clamped Nano-Oscillators

2014 ◽  
Author(s):  
A. Bhushan ◽  
M. M. Inamdar ◽  
D. N. Pawaskar
Keyword(s):  
Operating Temperature ◽  
Design Method ◽  
Design Procedure ◽  
Beam Theory ◽  
Frequency Stability ◽  
Internal Stresses ◽  
Frequency Variation ◽  
Electrostatically Actuated ◽  
Highly Sensitive ◽  
Natural Frequency Variation

Frequency stability is a desirable property for micro- and nanoelectromechanical system oscillators used in reference and timing applications. In case of doubly-clamped oscillators, resonant frequencies are highly sensitive to the operating temperature because of development of internal stresses due to thermal expansion under the restraint of fixed boundary conditions. In this paper, we present a design procedure to reduce the variation of resonant frequency with respect to change in operating temperature, in other words improve the frequency stability, by exploiting the interaction between electrostatic and geometric nonlinearities in electrostatically actuated doubly-clamped nano-oscillators. We have modeled the nano-oscillators using Euler-Bernoulli beam theory and Galerkin based reduced order modeling technique. We have examined first natural frequency variation due to temperature change for different carbon nanotube oscillators and an optimization based design procedure has been devised for improving the frequency stability.

scholarly journals A Two-Round Optimization Design Method for Aerostatic Spindles Considering the Fluid–Structure Interaction Effect

2021 ◽  
Vol 11 (7) ◽  
pp. 3017
Author(s):  
Qiang Gao ◽  
Siyu Gao ◽  
Lihua Lu ◽  
Min Zhu ◽  
Feihu Zhang
Keyword(s):  
Optimal Design ◽  
Optimization Design ◽  
Design Method ◽  
Fluid Structure Interaction ◽  
Design Procedure ◽  
Design Parameters ◽  
Geometrical Parameters ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Aerostatic Spindle

The fluid–structure interaction (FSI) effect has a significant impact on the static and dynamic performance of aerostatic spindles, which should be fully considered when developing a new product. To enhance the overall performance of aerostatic spindles, a two-round optimization design method for aerostatic spindles considering the FSI effect is proposed in this article. An aerostatic spindle is optimized to elaborate the design procedure of the proposed method. In the first-round design, the geometrical parameters of the aerostatic bearing were optimized to improve its stiffness. Then, the key structural dimension of the aerostatic spindle is optimized in the second-round design to improve the natural frequency of the spindle. Finally, optimal design parameters are acquired and experimentally verified. This research guides the optimal design of aerostatic spindles considering the FSI effect.

scholarly journals A Shape Optimization Method for Part Design Derived from the Buildability Restrictions of the Directed Energy Deposition Additive Manufacturing Process

Designs ◽  
2020 ◽  
Vol 4 (3) ◽  
pp. 19
Author(s):  
Andreas K. Lianos ◽  
Harry Bikas ◽  
Panagiotis Stavropoulos
Keyword(s):  
Topology Optimization ◽  
Additive Manufacturing ◽  
Energy Deposition ◽  
Design Method ◽  
Current Trend ◽  
Internal Stresses ◽  
Material Distribution ◽  
Load Case ◽  
Design Elements ◽  
Industrial Sectors

The design methodologies and part shape algorithms for additive manufacturing (AM) are rapidly growing fields, proven to be of critical importance for the uptake of additive manufacturing of parts with enhanced performance in all major industrial sectors. The current trend for part design is a computationally driven approach where the parts are algorithmically morphed to meet the functional requirements with optimized performance in terms of material distribution. However, the manufacturability restrictions of AM processes are not considered at the primary design phases but at a later post-morphed stage of the part’s design. This paper proposes an AM design method to ensure: (1) optimized material distribution based on the load case and (2) the part’s manufacturability. The buildability restrictions from the direct energy deposition (DED) AM technology were used as input to the AM shaping algorithm to grant high AM manufacturability. The first step of this work was to define the term of AM manufacturability, its effect on AM production, and to propose a framework to estimate the quantified value of AM manufacturability for the given part design. Moreover, an AM design method is proposed, based on the developed internal stresses of the build volume for the load case. Stress tensors are used for the determination of the build orientation and as input for the part morphing. A top-down mesoscale geometric optimization is used to realize the AM part design. The DED Design for Additive Manufacturing (DfAM) rules are used to delimitate the morphing of the part, representing at the same time the freeform mindset of the AM technology. The morphed shape of the part is optimized in terms of topology and AM manufacturability. The topology optimization and AM manufacturability indicator (TMI) is introduced to screen the percentage of design elements that serve topology optimization and the ones that serve AM manufacturability. In the end, a case study for proof of concept is realized.

AN INDEPENDENT ACTIVE BALANCER FOR PLANAR MECHANISMS

2007 ◽  
Vol 31 (2) ◽  
pp. 167-190 ◽  
Author(s):  
Zhang Ying ◽  
Yao Yan-An ◽  
Cha Jian-Zhong
Keyword(s):  
Working Conditions ◽  
Design Method ◽  
Design Procedure ◽  
Vibration Absorber ◽  
Planar Mechanisms ◽  
Dynamic Balancing ◽  
Joint Coupling ◽  
Design Requirements ◽  
Novel Concept ◽  
Two Degree Of Freedom

This paper proposed a novel concept of active balancer for dynamic balancing of planar mechanisms. Somewhat similar to a vibration absorber, the active balancer is designed as an independent device, which is placed outside of the mechanism to be balanced and can be installed easily. It consists of a two degree-of-freedom (DOF) linkage with two input shafts, one of which is connected to the output shaft of the mechanism to be balanced by a joint coupling, and the other one is driven by a controllable motor. Flexible dynamic balancing adapted to different working conditions can be achieved by varying speed trajectories of the control motor actively. A design method is developed for selecting suitable speed trajectories and link parameters of the two DOF linkage of the balancer to meet various design requirements and constraints. Numerical examples are given to demonstrate the design procedure and to verify the feasibility of the proposed concept.

scholarly journals Novel Robust Design Method of Multilayer Optical Coatings

ISRN Optics ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Suyong Wu ◽  
Xingwu Long ◽  
Kaiyong Yang
Keyword(s):  
Robust Design ◽  
Optimization Design ◽  
Design Method ◽  
Analytical Calculation ◽  
Design Procedure ◽  
Deposition Process ◽  
Practical Significance ◽  
Optical Coatings ◽  
Optical Films ◽  
Robust Design Method

We present a novel fast robust design method of multilayer optical coatings. The sensitivity of optical films to production errors is controlled in the whole optimization design procedure. We derive an analytical calculation model for fast robust design of multilayer optical coatings. We demonstrate its effectiveness by successful application of the robust design method to a neutral beam splitter. It is showed that the novel robust design method owns an inherent fast computation characteristic and the designed film is insensitive to the monitoring thickness errors in deposition process. This method is especially of practical significance to improve the mass production yields and repetitive production of high-quality optical coatings.

Multi Mode Vibration Control and Broder Band Motion Control of Three Dimensional Shaking Table

2005 ◽  
Author(s):  
Tsunehiro Wakasugi ◽  
Toru Watanabe ◽  
Kazuto Seto
Keyword(s):  
Vibration Control ◽  
Controller Design ◽  
Design Method ◽  
Three Dimensional ◽  
Design Procedure ◽  
Equation System ◽  
State Equation ◽  
Shaking Table ◽  
Mode Vibration ◽  
And Control

This paper deals with a new system design method for motion and vibration control of a three-dimensional flexible shaking table. An integrated modeling and controller design procedure for flexible shaking table system is presented. An experimental three-dimensional shaking table is built. “Reduced-Order Physical Model” procedure is adopted. A state equation system model is composed and a feedback controller is designed by applying LQI control law to achieve simultaneous motion and vibration control. Adding a feedforward, two-degree-of-freedom control system is designed. Computer simulations and control experiments are carried out and the effectiveness of the presented procedure is investigated. The robustness of the system is also investigated.

scholarly journals Semi-Inverse Design of Compressor Cascades, Including Supersonic Inflow

1990 ◽  
Author(s):  
A. Kirschner ◽  
H. Stoff
Keyword(s):  
Flow Field ◽  
Design Method ◽  
Axisymmetric Flow ◽  
Three Dimensional ◽  
Design Procedure ◽  
Meridional Plane ◽  
Simple Method ◽  
Blade Loading ◽  
Through Flow ◽  
Blade Element

A cascade design-method is presented which complements the meridional through-flow design procedure of turbomachines. Starting from an axisymmetric flow field and the streamline geometry in the meridional plane this simple method produces a solution for the quasi three-dimensional flow field and the blade-element geometry on corresponding stream surfaces. In addition, it provides intra-blade data on loss and turning required for a consistent design and a convenient means of optimizing blade loading. The purpose of this paper is to describe the theoretical basis of the method and to illustrate its application in the design of transonic compressors.

scholarly journals An Artificial Intelligence–Assisted Design Method for Topology Optimization without Pre-Optimized Training Data

2021 ◽  
Vol 11 (19) ◽  
pp. 9041
Author(s):  
Alex Halle ◽  
Lucio Flavio Campanile ◽  
Alexander Hasse
Keyword(s):  
Topology Optimization ◽  
Input Data ◽  
Design Method ◽  
Design Procedure ◽  
Computational Effort ◽  
Training Data ◽  
Geometry Design ◽  
Random Input Data ◽  
Degree Of Filling ◽  
Initial Process

Engineers widely use topology optimization during the initial process of product development to obtain a first possible geometry design. The state-of-the-art method is iterative calculation, which requires both time and computational power. This paper proposes an AI-assisted design method for topology optimization, which does not require any optimized data. An artificial neural network—the predictor—provides the designs on the basis of boundary conditions and degree of filling as input data. In the training phase, the so-called evaluators evaluate the generated geometries on the basis of random input data with respect to given criteria. The results of those evaluations flow into an objective function, which is minimized by adapting the predictor’s parameters. After training, the presented AI-assisted design procedure generates geometries that are similar to those of conventional topology optimizers, but require only a fraction of the computational effort. We believe that our work could be a clue for AI-based methods that require data that are difficult to compute or unavailable.

scholarly journals Experimental investigation of characteristics of a double-base swirl injector in a liquid rocket propellant engine

2010 ◽  
Vol 14 (2) ◽  
pp. 479-491 ◽  
Author(s):  
Fathollah Ommi ◽  
Koros Nekofar ◽  
Amir Kargar ◽  
Ehsan Movahed
Keyword(s):  
Design Method ◽  
Design Procedure ◽  
Computer Code ◽  
Cold Test ◽  
Spray Angle ◽  
Droplet Distribution ◽  
Swirl Injector ◽  
Liquid Rocket ◽  
Double Base ◽  
Base Liquid

In this work the fundamentals of swirl injector calculation is investigated and new design procedure is proposed. The design method for double-base liquid-liquid injectors is presented based on this theory and experimental results. Then special conditions related to double based liquid-liquid injectors are studied and the corresponding results are applied in design manipulation. The behavior of injector in various performing conditions is studied, and the design procedure is presented based on obtained results. A computer code for designing the injector is proposed. Based on this code, four injectors are manufactured. A specialized laboratory was setup for the measurement of macroscopic spray characteristics under different pressure such as homogeneous droplet distribution, spray angle, and swirl effect. Finally, through phase Doppler analyzer cold test, the microscopic characteristics of injectors spray are also obtained and measured. The results which will be explained in detail are satisfactory.

Design and Integrated Simulation of the Electro-Hydraulic Servo System Based on AMESim and Matlab

2010 ◽  
Vol 44-47 ◽  
pp. 1355-1359 ◽  
Author(s):  
Xiang Xu ◽  
Zhi Xiong Li ◽  
Hong Ling Qin
Keyword(s):  
Control System ◽  
Design Method ◽  
Design Procedure ◽  
Servo System ◽  
Hydraulic Cylinder ◽  
Fast Response ◽  
Simulation Design ◽  
Integrated Simulation ◽  
Hydraulic Servo ◽  
Hydraulic Servo System

Since electro-hydraulic servo system has fast response and highest control accuracy, it has been widely used in industrial application, including aircraft, mining, manufacturing, and agriculture, etc. With the fast development of computer science, it is feasible and available to evaluate the performance of the designed control system via virtual simulation before the practical usage of the system. In order to optimize the design procedure of the electro-hydraulic proportional controller, the co-simulation design method based on AMESim-Matlab is presented for the electro-hydraulic servo system in this paper. High accuracy of the mathematical model of electro-hydraulic servo system was full-fitted by the use of AMESim, and the advantage of high solving precision for large amount of calculation was full played using Matlab. The PID controller was employed to realize the efficient control of the motion of the hydraulic cylinder. The united simulation technique was adopted to verify the good performance of the designed control system. The simulation results suggest that the proposed method is effective for the design of electro-hydraulic servo systems and thus has application importance.

Design of Electrostatic Micro Mirrors for Improved Stability Though Surface Contact

1998 ◽  
Author(s):  
Timothy Moulton ◽  
G. K. Ananthasuresh
Keyword(s):  
Design Method ◽  
Electrostatic Force ◽  
Electrostatic Actuation ◽  
Mems Devices ◽  
Complex Dynamic ◽  
Micro Electro Mechanical Systems ◽  
Electrostatically Actuated ◽  
Surface Contact ◽  
Improved Stability ◽  
Mems Process

Abstract There exists a need to stabilize the electrostatic actuation commonly used in Micro-Electro-Mechanical Systems (MEMS). Most electrostatically actuated MEMS devices act as variable capacitors with varying gap between the charged conductors. Electrostatic force in these devices is a nonlinear attractive force between the conductors resulting in a complex dynamic system. These systems are stable for only a small portion of the initial gap. In this paper a design method is presented for electrostatic micro-mirrors with improved stability. Controllable, stable electrostatic actuation can be achieved through surface contact between the two conductors. Once in contact with the surface, the compliance of the structure is used to stabilize the electrostatic actuation over a long range of motion. Beam based variable angle mirrors were designed and fabricated using the Multi-User MEMS Process at MCNC technology center. The design methods for stable electrostatic actuation were tested on these mirrors. Some characteristics are noted and their implementation into future designs is discussed.

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