scholarly journals High-Output Micro-Machined Electrostatic Actuators

2021 ◽  
Author(s):  
Amin Abbasalipour ◽  
Prithviraj Palit ◽  
Sepehr Sheikhlari ◽  
Siavash Pakdelian ◽  
Siavash Pourkamali
Keyword(s):  
Axial Force ◽  
Bending Moment ◽  
Cross Sectional ◽  
Electrostatic Actuators ◽  
New Class ◽  
Output Force ◽  
Mems Actuators ◽  
Out Of Plane ◽  
Animal Muscle ◽  
Plane Displacement

Abstract This work presents a new class of micromachined electrostatic actuators capable of producing output force and displacement unprecedented for MEMS actuators. The actuators feature submicron high aspect ratio transduction gaps lined up in two-dimensional arrays inspired by the cellular structure of animal muscle tissue. Such arrangement of micro-scale actuator cells, allows addition of force and displacements of a large number of cells (up to 7600 in one array demonstrated), leading to displacements in the hundreds of microns range and several gram-forces of axial force. For 50 µm thick actuators with horizontal dimensions in the 1-4 millimeters range, out of plane displacement of up to 678 µm, bending moment of up to 2.0 µNm i.e. 0.08 N (~8 gram-force) of axial force over the 50 µm by 2 mm cross-sectional area of the actuator (800 kPa of electrostatically generated stress), and energy density (mechanical work output per stroke per volume) up to 1.42 mJ/cm3 have been demonstrated for the actuators.

scholarly journals Stress Distribution Analysis of DKDT Tubular Joint in a Minimum Offshore Structure

Rekayasa ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 191-199
Author(s):  
Irma Noviyanti ◽  
Rudi Walujo Prastianto ◽  
Murdjito Murdjito
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Axial Force ◽  
Oil And Gas ◽  
Bending Moment ◽  
Out Of Plane ◽  
Tubular Joint ◽  
Plane Bending ◽  
Intersection Line ◽  
Marginal Field

A marginal field defines as an oil and/or gas field that has a short production period, low proven reservoir, and could not be exploited using existing technology. As the demand for oil and gas keeps increasing, one of the solutions to tackle the issues is to build the modified platform which came to be more minimalist to conduct the oil and gas production in the marginal field. Naturally, the minimum offshore structures are cost less but low in redundancy, therefore, pose more risks. Although the study on the minimum structures is still uncommon, there are opportunities to find innovative systems that need to have a further analysis toward such invention. Therefore, this study took the modified jacket platform as a minimum structure, and local stresses analysis by using finite element method is applied for the most critical tubular joint with multiplanarity of the joint is taking into account. The analysis was carried out using the finite element program of Salome Meca with three-dimensional solid elements are used to model the multiplanar joint. Various loading types of axial force, in-plane bending moment, and out-of-plane bending moment are applied respectively to investigate the stress distribution along the brace-chord intersection line of the tubular joint. The results show that the hotspot stress occurred at a different point along each brace-chord intersection line for each loading type. Finally, as compared to the in-plane bending moment or out-of-plane bending moment loading types, the axial force loading state is thought to generate greater hotspot stress.

scholarly journals Cross-Sectional Analysis of the Resistance of Rc Members Subjected to Bending With/without Axial Force

2021 ◽  
Author(s):  
Marek Lechman
Keyword(s):  
Cross Section ◽  
Axial Force ◽  
Rectangular Cross Section ◽  
Bending Moment ◽  
Equilibrium Equations ◽  
Cross Sectional ◽  
Cross Sectional Analysis ◽  
Nonlinear Stress ◽  
The Cross ◽  
Sectional Analysis

The paper presents section models for analysis of the resistance of RC members subjected to bending moment with or without axial force. To determine the section resistance the nonlinear stress-strain relationship for concrete in compression is assumed, taking into account the concrete softening. It adequately describes the behavior of RC members up to failure. For the reinforcing steel linear elastic-ideal plastic model is applied. For the ring cross-section subjected to bending with axial force the normalized resistances are derived in the analytical form by integrating the cross-sectional equilibrium equations. They are presented in the form of interaction diagrams and compared with the results obtained by testing conducted on RC columns under eccentric compression. Furthermore, the ultimate normalized bending moment has been derived for the rectangular cross-section subjected to bending without axial force. It was applied in the cross-sectional analysis of steel and concrete composite beams, named BH beams, consisting of the RC rectangular core placed inside a reversed TT welded profile. The comparisons made indicated good agreements between the proposed section models and experimental results.

Design, Simulation and Optimization of Electrothermal Micro Actuator

2012 ◽  
Vol 229-231 ◽  
pp. 1939-1943 ◽  
Author(s):  
Abid Ali ◽  
R.A. Azim ◽  
U.S. Khan ◽  
A.A. Syed ◽  
U. Izhar
Keyword(s):  
Time Constant ◽  
Temperature Increase ◽  
Thermal Time ◽  
Design And Optimization ◽  
Simulation And Optimization ◽  
Micro Actuator ◽  
Thermal Time Constant ◽  
Mems Actuators ◽  
Out Of Plane ◽  
Plane Displacement

This work presents the design and optimization of out of plane electrothermal MEMS actuators. The proposed concept is capable of generating large out of plane displacement at low driving power and a low actuation temperature. The performance of this actuator is evaluated and simulated in ANSYS. The out of plane displacement of 291µm at a temperature increase of 135°C from ambient has been achieved with the applied power of 2.7mW(0.7V). Moreover, a thermal time constant of 5.6ms and a frequency of 85Hz is accomplished for this actuator.

scholarly journals Development of electrostatic actuators with large out-of-plane deflection and its application in scanning display

2021 ◽  
Author(s):  
Chao Fan
Keyword(s):  
Rotation Angle ◽  
Low Cost ◽  
Repulsive Force ◽  
Thin Layers ◽  
Driving Voltage ◽  
Plane Rotation ◽  
Electrostatic Actuators ◽  
Scanning Angle ◽  
Out Of Plane ◽  
Plane Displacement

Electrostatic out-of-plane microactuators have been widely used in applications of variable capacitors, optical attenuators, optical switches and scanning displays due to their small size, low cost, simple and diverse structure, low power consumption and high compatibility with semiconductor process. The large out-of-plane displacement of the microactuator with high reliability is preferred in order to increase the tuning range, tunability and the display size. However, the “pull-in” instability associated with conventional attractive-force electrostatic microactuators significantly limits the out-of-plane displacement and lowers the operation stability. A repulsive-force microactuator has been previously developed which can achieve large out-of-plane rotation and does not suffer from the “pull-in” instability. However, a larger rotation angle of the repulsive-force actuator is highly desired in order to improve its performance in the applications such as increasing the tunability and the scanning angle. In this thesis two novel repulsive-force actuators, i.e., two-row interdigitating-finger and two-width-finger (TWF) actuators are developed which output much larger out-of-plane rotation than the previous repulsive-force actuator without suffering from the “pull-in” instability. The mathematical models are established for both actuators using a hybrid approach. The actuators require only two thin layers and are suitable for surface micromachining process. The measured results show that the two microactuators can achieve rotation angles of 11.5° and 7.5° at 150 V respectively. The improvements are 100% and 35% in comparison to the previous repulsive-force actuator with the same size, stiffness and driving voltage. A 2D scanning micromirror has been developed and fabricated based on the two-row-finger (TRF) actuator. Experimental results show the micromirror has larger rotation angle and faster response speed than those of the micromirror driven by the previous repulsive-force microactuator. The vector scanning display based on the micromirror is demonstrated. An advanced display approach is developed to generate displays with less distortion and higher refreshing rate compared to the previous generic display approach. The automotive Head-up Display (HUD) based on the micromirror and advanced display approach has been constructed for both real and virtual image configurations, which has advantages of small size, low cost, large viewing angle and good visibility over those HUDs in the market.

scholarly journals Development of electrostatic actuators with large out-of-plane deflection and its application in scanning display

2021 ◽  
Author(s):  
Chao Fan
Keyword(s):  
Rotation Angle ◽  
Low Cost ◽  
Repulsive Force ◽  
Thin Layers ◽  
Driving Voltage ◽  
Plane Rotation ◽  
Electrostatic Actuators ◽  
Scanning Angle ◽  
Out Of Plane ◽  
Plane Displacement

Electrostatic out-of-plane microactuators have been widely used in applications of variable capacitors, optical attenuators, optical switches and scanning displays due to their small size, low cost, simple and diverse structure, low power consumption and high compatibility with semiconductor process. The large out-of-plane displacement of the microactuator with high reliability is preferred in order to increase the tuning range, tunability and the display size. However, the “pull-in” instability associated with conventional attractive-force electrostatic microactuators significantly limits the out-of-plane displacement and lowers the operation stability. A repulsive-force microactuator has been previously developed which can achieve large out-of-plane rotation and does not suffer from the “pull-in” instability. However, a larger rotation angle of the repulsive-force actuator is highly desired in order to improve its performance in the applications such as increasing the tunability and the scanning angle. In this thesis two novel repulsive-force actuators, i.e., two-row interdigitating-finger and two-width-finger (TWF) actuators are developed which output much larger out-of-plane rotation than the previous repulsive-force actuator without suffering from the “pull-in” instability. The mathematical models are established for both actuators using a hybrid approach. The actuators require only two thin layers and are suitable for surface micromachining process. The measured results show that the two microactuators can achieve rotation angles of 11.5° and 7.5° at 150 V respectively. The improvements are 100% and 35% in comparison to the previous repulsive-force actuator with the same size, stiffness and driving voltage. A 2D scanning micromirror has been developed and fabricated based on the two-row-finger (TRF) actuator. Experimental results show the micromirror has larger rotation angle and faster response speed than those of the micromirror driven by the previous repulsive-force microactuator. The vector scanning display based on the micromirror is demonstrated. An advanced display approach is developed to generate displays with less distortion and higher refreshing rate compared to the previous generic display approach. The automotive Head-up Display (HUD) based on the micromirror and advanced display approach has been constructed for both real and virtual image configurations, which has advantages of small size, low cost, large viewing angle and good visibility over those HUDs in the market.

scholarly journals INTERACTION DIAGRAMS AXIAL FORCE-BENDING MOMENT FOR FIRE EXPOSED STEEL-CONCRETE COMPOSITE SECTIONS

2016 ◽  
Author(s):  
Milivoje Milanovic ◽  
Meri Cvetkovska
Keyword(s):  
Bearing Capacity ◽  
Cross Section ◽  
Axial Force ◽  
Bending Moment ◽  
Cross Sectional ◽  
Load Bearing ◽  
Composite Columns ◽  
Interaction Diagram ◽  
Steel Sections ◽  
The Cross

The bearing capacity of the column cross section can be determined from the interaction diagram moment-axial force (M–N). Fire induced temperatures cause reduction of the load-bearing characteristics of the constitutive materials, steel and concrete, and this effect directly reflects on the reduction of the axial force and the bending moment that could be accepted by the column cross section, respectively the interaction diagram of the column cross section is changed. The load bearing capacity of the steel-concrete composite columns exposed to fire from all four sides and loaded by axial force and uni-axial or bi-axial bending moments, was estimated on the basis of the changes in the interaction diagrams moment-axial force amd the results are presented in this paper. Different types of composite columns made of totally or partially encased steel sections, or concrete filled hollow sections were analyzed and a detailed discussion on the effects of the shape of the cross section and the cross sectional dimensions are presented.

Ultimate Bending Capacity and Buckling of Pressurized 90 deg Steel Elbows

2005 ◽  
Vol 128 (3) ◽  
pp. 348-356 ◽  
Author(s):  
S. A. Karamanos ◽  
D. Tsouvalas ◽  
A. M. Gresnigt
Keyword(s):  
Local Buckling ◽  
Bending Moment ◽  
General Purpose ◽  
Moderate Pressure ◽  
Cross Sectional ◽  
Finite Element Program ◽  
Shell Elements ◽  
Out Of Plane ◽  
Bending Capacity ◽  
Plane Bending

The paper examines the nonlinear elastic-plastic response of internally pressurized 90 deg pipe elbows under in-plane and out-of-plane bending. Nonlinear shell elements from a general-purpose finite element program are employed to model the inelastic response of steel elbows and the adjacent straight parts. The numerical results are successfully compared with real-scale experimental measurements. The paper also presents a parametric study, aimed at investigating the effects of diameter-to-thickness ratio and moderate pressure levels on the ultimate bending capacity of 90 deg elbows, focusing on the failure mode (local buckling or cross-sectional flattening) and the maximum bending moment. Special attention is given to the response of 90 deg elbows under out-of-plane bending moments.

Force Relationships for an XYZ Micromanipulator With Three Translational Degrees of Freedom

2004 ◽  
Author(s):  
Kimberly A. Jensen ◽  
Craig P. Lusk ◽  
Larry L. Howell
Keyword(s):  
Rigid Body ◽  
Degrees Of Freedom ◽  
Input Output ◽  
Force Analysis ◽  
Displacement Analysis ◽  
Input Force ◽  
Output Force ◽  
Out Of Plane ◽  
Plane Displacement

This paper introduces the force analysis of the XYZ Micromanipulator (XYZM). The XYZM has three independent linear inputs and a positioning platform. The positioning platform remains horizontal throughout its motion and has translation in the x, y, and z directions. The design and displacement analysis for the XYZM was reported previously. This paper concentrates on the input-output force relationships and the derivation of the XYZM kinematic coefficients. Equations for the three versions of the XYZM are reported and sample results provided. Slider displacements of 45 micrometers result in a predicted out-of-plane displacement of 188 micrometers for the rigid-body XYZM and 262 micrometers for the compliant XYZM. This correlates to output force of 286 micronewtons with an input force of 150 micronewtons for the rigid-body XYZM and 261 micronewton output force with an input force of 150 micronewtons for the compliant XYZM.

scholarly journals Nonlinear analysis of lightweight aggregate concrete columns

2020 ◽  
Vol 19 (3) ◽  
pp. 081-091
Author(s):  
Ewelina Kołodziejczyk ◽  
Tomasz Waśniewski
Keyword(s):  
Axial Force ◽  
Bending Moment ◽  
Lightweight Aggregate ◽  
Normal Weight ◽  
Ultimate Strain ◽  
Nonlinear Material ◽  
Lightweight Aggregate Concrete ◽  
Peak Strain ◽  
Cross Sectional ◽  
Aggregate Concrete

The paper presents a numerical analysis of deformability and load-bearing capacity of lightweight aggregate concrete (LWAC) elements subjected to bending with axial force. The nonlinear material model of LWAC presented in Eurocode 2 (EC2) was assumed. Several different densities and compressive strengths of concrete were taken into account. The investigations included the comparison of the sectional capacity and the behaviour of slender elements made with normal and lightweight aggregate concrete. It was observed that density-dependent mechanical properties of concrete affect the obtained values of the maximum axial force and the bending moment despite the same mean compressive strength. In every case, the capacity of the RLWAC section was lower than the one of normal weight, which was caused by a linear characteristic of the LWAC. Other important factors were the modulus of elasticity and the ultimate strain of concrete. LWAC with the higher density and the lower ultimate strain gave greater stiffness to slender columns but reduced the cross-sectional capacity. It was concluded that the elastic modulus and the peak strain of LWAC which are applied in columns calculations should be verified experimentally.

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