scholarly journals A Modified U-Shaped Micro-Actuator with a Compliant Mechanism Applied to a Microgripper

Actuators ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 28 ◽  
Author(s):  
Pedro Vargas-Chable ◽  
Margarita Tecpoyotl-Torres ◽  
Ramon Cabello-Ruiz ◽  
Jose Rodriguez-Ramirez ◽  
Rafael Vargas-Bernal
Keyword(s):  
Stress Reduction ◽  
Room Temperature ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Equivalent Stress ◽  
Performance Parameters ◽  
The Finite Element Method ◽  
Micro Actuator ◽  
The Impact ◽  
Ansys Workbench

In this paper, a modified U-shaped micro-actuator with a compliant mechanism is proposed. It was analyzed with a uniform and modified thin arm, as well as a similar variation in the corresponding flexure, in order to observe the impact of the compliant lumped mechanism. The use of these compliant mechanisms implies an increment in the deformation and a reduction in the equivalent stress of 25% and 52.25%, respectively. This characterization was developed using the Finite Element Method (FEM) in ANSYS Workbench. The design, analysis and simulation were developed with Polysilicon. In this study, the following performance parameters were also analyzed: force and temperature distribution. This device is supplied with voltage from 0 V up to 3 V, at room temperature. The modified U-shaped actuator was applied in both arms of a microgripper, and to evaluate its electrothermal performance, a static structural analysis has been carried out in Ansys Workbench. The microgripper has an increment in deformation of 22.33%, an equivalent stress reduction of 50%, and a decrease in operation frequency of 10.8%. The force between its jaws is of 367 µN. This low level of force could be useful when sensitive particles are manipulated.

Dynamic Analysis and Design of Compliant Mechanisms Using the Finite Element Method

2012 ◽  
Vol 163 ◽  
pp. 111-115 ◽  
Author(s):  
Wen Jing Wang ◽  
Li Ge Zhang ◽  
Shu Sheng Bi
Keyword(s):  
Finite Element Method ◽  
Dynamic Model ◽  
Natural Frequency ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
The Finite Element Method ◽  
Dynamic Effects ◽  
Experiment System ◽  
Analysis And Design ◽  
Theoretical Results

Compliant mechanisms gain at least some of their mobility from the deflection of flexible members rather than from movable joints only. Dynamic effects are very important to improving the design of compliant mechanisms. An investigation on the dynamics and synthesis of the compliant mechanisms is presented. The dynamic model of compliant mechanisms is developed at first. The natural frequency and sensitivity are then studied based on the dynamic model. Finally, optimal design of compliant mechanism is investigated. The experimental study of natural frequency is performed. The comparison between the experiment results and the theoretical results verifies the validity of the experiment system and theoretical model.

scholarly journals Crash Analysis on the Automotive Vehicle Bumper

2019 ◽  
Vol 8 (6S3) ◽  
pp. 1602-1607 ◽  
Keyword(s):  
Impact Analysis ◽  
Equivalent Stress ◽  
Suitable Material ◽  
Material Optimization ◽  
Analysis Process ◽  
Modeling Process ◽  
Materials Used ◽  
Two Stages ◽  
The Impact ◽  
Ansys Workbench

In this article deals the crash investigation of Bumper for different materials using ANSYS Workbench. Bumper is a vital parameter which is used as safety protection for passengers from accidents by means of impact energy absorption from collision environment. The ultimate focus of this work is material optimization for Bumper by performing impact analysis with the help of ANSYS. The entire analysis process comprises of two stages, which are conceptual design of Bumper and preparation of Bumper for numerical analysis. The optimization of this work is based on structural parametric results, in which total deformation, equivalent stress induced are primarily involved. . The reference component’s modeling process is completed by means of CATIA, and then the impact analysis is carried by ANSYS Workbench 16.2, in which the materials used for bumper are Steel and Glass fiber based composite with the constant boundary conditions [speed = 13.3 m sec-1]. Finally suitable material is finalized for car bumper.

On the Stress Responses in Butt Joint under Izod Impact Testing

2014 ◽  
Vol 488-489 ◽  
pp. 542-545 ◽  
Author(s):  
Min You ◽  
Kai Liu ◽  
Xiang Li ◽  
Ling Wu ◽  
Mei Li
Keyword(s):  
Stress Responses ◽  
Equivalent Stress ◽  
Adhesive Layer ◽  
Butt Joint ◽  
Impact Testing ◽  
The Finite Element Method ◽  
Adhesively Bonded ◽  
Izod Impact ◽  
The Impact ◽  
Peak Value

The response of the equivalent stress (Seqv) in adhesively bonded steel butt joint and the adhesive bondline during Izod impact test is studied using the finite element method (FEM) software ANSYS. The results obtained show that the highest value of the stressSeqvalmost higher than the yield strength of the adherend reached within about 0.1 ms. The contour diagram of the stressSeqvis symmetrical to the axis along the half height of the specimen both in whole adhesively bonded steel butt joint and the adhesive layer. The peak value of theSeqvin adhesive increases first and then decreased when the action of the impact was over. The stressSeqvin both ends of the specimen kept to a relative lower value during impact procedure.

scholarly journals Force Diverting Helmet Liner Achieved Through a Lattice of Multi-Material Compliant Mechanisms

2017 ◽  
Author(s):  
Vaibhav Gokhale ◽  
Prasad Tapkir ◽  
Andres Tovar
Keyword(s):  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Radial Force ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Linear Force ◽  
The One ◽  
Von Mises ◽  
Energy Absorbing ◽  
The Impact

This work introduces the design of a lattice array of multi-material compliant mechanisms (LCM) that diverts the impact radial force into tangential forces through the action of elastic hinges and connecting springs. When used as the helmet liner, the LCM liner design has the potential to reduce the risk of head injury through improved impact energy attenuation. The compliant mechanism array in the liner is optimized using a multi-material topology optimization algorithm. The performance of the LCM liner design is compared with the one obtained by expanded polypropylene (EPP) foam, which is traditionally used in sport helmets. An impact test is carried out using explicit, dynamic, nonlinear finite element analysis. The parameters under consideration include the internal energy, the peak linear force, as well as von Mises stress and effective plastic strain distributions. Although there is a small increase in stress and strain values, the simulations show that the maximum internal of the LCM liner design is four times the one of the foam design while the peak linear force is reduced to about half. While the use of the LCM liner design is intended for sports helmets, this design may find application in other energy absorbing structures such as crashworthy vehicle components, blast mitigating structures, and protective gear.

scholarly journals Multi-platform app-embedded model for hybrid air-breathing rocket-cycle engine in hypersonic atmospheric ascent

2021 ◽  
pp. 1-23
Author(s):  
S.E. Tsentis ◽  
V.G. Gkoutzamanis ◽  
A.D. Gaitanis ◽  
A.I. Kalfas
Keyword(s):  
Specific Impulse ◽  
Performance Parameters ◽  
Interested Reader ◽  
Component Level ◽  
Air Breathing ◽  
Evaluation Of Performance ◽  
Embedded Model ◽  
The Impact ◽  
Rocket Technology ◽  
Engine Concept

ABSTRACT This paper presents a performance analysis on a novel engine concept, currently under development, in order to achieve hybrid air-breathing rocket technology. A component-level approach has been developed to simulate the performance of the engine at Mach 5, and the thermodynamic interaction of the different working fluids has been analysed. The bypass ramjet duct has also been included in the model. This facilitates the improved evaluation of performance parameters. The impact of ram drag induced by the intake of the engine has also been demonstrated. The whole model is introduced into a multi-platform application for aeroengine simulation to make it accessible to the interested reader. Results show that the bypass duct modelling increases the overall efficiency by approximately 7%. The model calculates the specific impulse at approximately 1800 seconds, which is 4 times higher than any chemical rocket.

Influence of new surface micro-structures on the performance behaviours of fluid film tilting pad thrust bearings

2021 ◽  
pp. 095440622110309
Author(s):  
JC Atwal ◽  
RK Pandey
Keyword(s):  
Mass Conservation ◽  
Performance Parameters ◽  
Algebraic Equations ◽  
The Finite Element Method ◽  
Thrust Bearings ◽  
Lubrication Equation ◽  
Tilting Pad ◽  
Minimum Film Thickness ◽  
Newton Raphson ◽  
Micro Structures

Performance parameters such as power loss, minimum film thickness, and maximum oil temperature of the sector-shaped tilting pad thrust bearings employing the new micro-structural geometries on pad surfaces have been investigated. The lubrication equation incorporating the mass-conservation issue is discretized using the finite element method and the solution of resulting algebraic equations is obtained employing a Newton-Schur method. The pad equilibrium in the analysis is established using the Newton-Raphson and Braydon methods. The influence of attributes of micro-structures such as depth, circumferential and radial positioning extents have been explored on the performance behaviours. It is found that with the new micro-structured pad surfaces, the performance parameters significantly improved in comparison to conventional plain and conventional rectangular pocketed pads.

237 Stable Performance with Reduced Antibiotic Use in Piglets Vaccinated with an E. coli F4/F18 Vaccine for the Prevention of F18-ETEC Post-weaning Diarrhea

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 139-140
Author(s):  
Frédéric A Vangroenweghe
Keyword(s):  
Antibiotic Use ◽  
Watery Diarrhea ◽  
Economic Losses ◽  
Standard Group ◽  
Performance Parameters ◽  
Oral Vaccination ◽  
E Coli ◽  
Technical Performance ◽  
Stable Performance ◽  
The Impact

Abstract Post-weaning Escherichia coli diarrhea (PWD) remains a major cause of economic losses for the pig industry. PWD, caused by enterotoxigenic E. coli (ETEC), typically provokes mild to severe watery diarrhea between 5–10 days after weaning. Recently, an oral live bivalent E. coli F4/F18 vaccine (Coliprotec® F4/F18; Elanco) was approved on the European market, which reduces the impact of PWD provoked by F4-ETEC and F18-ETEC. The objective was to compare technical results and antibiotic use following E. coli F4/F18 vaccination with previous standard therapeutic approach under field conditions. A 1600-sow farm (weaning at 26 days) with diagnosed problems of PWD due to F18-ETEC was selected. Piglets were vaccinated at 21 days with the oral live bivalent E. coli F4/F18 vaccine. At weaning, no standard group medication (ZnO and antibiotics) was applied for prevention of PWD. Several performance parameters were collected: treatment incidence (TI100), mortality and days in nursery. Statistical analysis was performed using JMP 14.0 – comparison of means. Oral E. coli F4/F18 vaccination significantly reduced TI100 (7 ± 2 days to 0 ± 1 days; P < 0.05). Mortality rate remained stable (2.05% in Control to 1.96% in Vaccinated group; P < 0.05). Days in nursery (40 ± 3 days) remained at the same level compared to pre-vaccination. The results show that live E. coli F4/F18 vaccination against PWD has led to similar technical performance parameters and mortality, in combination with a significant reduction in medication use. In conclusion, control of PWD through oral vaccination is a successful option in order to prevent piglets from the negative clinical outcomes of F18-ETEC infection during the post-weaning period.

scholarly journals The effect of the outlet angle β2 on the thermomechanical behavior of a centrifugal compressor blade

2020 ◽  
Vol 29 (1) ◽  
pp. 1-8
Author(s):  
Ahmed Allali ◽  
Sadia Belbachir ◽  
Ahmed Alami ◽  
Belhadj Boucham ◽  
Abdelkader Lousdad
Keyword(s):  
Mechanical Behavior ◽  
Centrifugal Compressor ◽  
Three Dimensional ◽  
Complex Form ◽  
Compressor Blade ◽  
Stress Fields ◽  
The Finite Element Method ◽  
Mechanical Fatigue ◽  
Outlet Angle ◽  
The Impact

AbstractThe objective of this work lies in the three-dimensional study of the thermo mechanical behavior of a blade of a centrifugal compressor. Numerical modeling is performed on the computational code "ABAQUS" based on the finite element method. The aim is to study the impact of the change of types of blades, which are defined as a function of wheel output angle β2, on the stress fields and displacements coupled with the variation of the temperature.This coupling defines in a realistic way the thermo mechanical behavior of the blade where one can note the important concentrations of stresses and displacements in the different zones of its complex form as well as the effects at the edges. It will then be possible to prevent damage and cracks in the blades of the centrifugal compressor leading to its failure which can be caused by the thermal or mechanical fatigue of the material with which the wheel is manufactured.

scholarly journals Investigating the Impact of Brief Outings on the Welfare of Dogs Living in US Shelters

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 548
Author(s):  
Lisa M. Gunter ◽  
Rachel J. Gilchrist ◽  
Emily M. Blade ◽  
Rebecca T. Barber ◽  
Erica N. Feuerbacher ◽  
...  
Keyword(s):  
Stress Reduction ◽  
Physiological Measures ◽  
Urinary Cortisol ◽  
Short Term ◽  
Animal Shelters ◽  
Time Out ◽  
Before And After ◽  
Activity Measures ◽  
The Impact ◽  
Low Activity

Social isolation likely contributes to reduced welfare for shelter-living dogs. Several studies have established that time out of the kennel with a person can improve dogs’ behavior and reduce physiological measures of stress. This study assessed the effects of two-and-a-half-hour outings on the urinary cortisol levels and activity of dogs as they awaited adoption at four animal shelters. Dogs’ urine was collected before and after outings for cortisol:creatinine analysis, and accelerometer devices were used to measure dogs’ physical activity. In total, 164 dogs participated in this study, with 793 cortisol values and 3750 activity measures used in the statistical analyses. We found that dogs’ cortisol:creatinine ratios were significantly higher during the afternoon of the intervention but returned to pre-field trip levels the following day. Dogs’ minutes of low activity were significantly reduced, and high activity significantly increased during the outing. Although dogs’ cortisol and activity returned to baseline after the intervention, our findings suggest that short-term outings do not confer the same stress reduction benefits as previously shown with temporary fostering. Nevertheless, it is possible that these types of outing programs are beneficial to adoptions by increasing the visibility of dogs and should be further investigated to elucidate these effects.

scholarly journals Manufacturing, Characterisation and Mechanical Analysis of Polyacrylonitrile Membranes

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2378
Author(s):  
Mertol Tüfekci ◽  
Sevgi Güneş Durak ◽  
İnci Pir ◽  
Türkan Ormancı Acar ◽  
Güler Türkoğlu Demirkol ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Main Idea ◽  
Mechanical Analysis ◽  
Operating Conditions ◽  
Load Carrying Capacity ◽  
The Finite Element Method ◽  
Load Carrying ◽  
The Impact ◽  
Static Behaviour ◽  
Modelling Process

To investigate the effect of polyvinylpyrrolidone (PVP) addition and consequently porosity, two different sets of membranes are manufactured, since PVP is a widely used poring agent which has an impact on the mechanical properties of the membrane material. The first set (PAN 1) includes polyacrylonitrile (PAN) and the necessary solvent while the second set (PAN 2) is made of PAN and PVP. These membranes are put through several characterisation processes including tensile testing. The obtained data are used to model the static behaviour of the membranes with different geometries but similar loading and boundary conditions that represent their operating conditions. This modelling process is undertaken by using the finite element method. The main idea is to investigate how geometry affects the load-carrying capacity of the membranes. Alongside membrane modelling, their materials are modelled with representative elements with hexagonal and rectangular pore arrays (RE) to understand the impact of porosity on the mechanical properties. Exploring the results, the best geometry is found as the elliptic membrane with the aspect ratio 4 and the better RE as the hexagonal array which can predict the elastic properties with an approximate error of 12%.

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