Modeling and analysis of an electro-magneto-elastic rotating cylindrical tube actuator

2022 ◽  
pp. 1045389X2110721
Author(s):  
Deepak Kumar ◽  
Vinod Yadav ◽  
Somnath Sarangi
Keyword(s):  
Electromagnetic Field ◽  
Volume Fraction ◽  
Cylindrical Tube ◽  
Longitudinal Axis ◽  
Mechanical Instability ◽  
Modeling And Analysis ◽  
Precise Control ◽  
Static Modeling ◽  
Parametric Studies ◽  
Smart Actuator

This paper presents the static modeling and analysis of a novel cylindrical tube actuator subjected to a rotation about longitudinal axis with an internally applied air pressure under an electromagnetic field. The current tube actuator belongs to a smart actuator category and is made of an electro-magneto-active polymer filled with a particular volume fraction of suitable fillers. A continuum mechanics-based electro-magneto-mechanical model is developed to predict the response of the actuator for a combined pressure and electromagnetic field loading. To validate the same, the model is compared with the outputs of an existing spring roll actuator. Parametric studies are subsequently performed for varying input pressure, electric field, magnetic field, fillers content, and actuator’s rotational speed. The output sensitivity in terms of strain intensity at inner and outer surfaces of the actuator is also checked at different controlling inputs. In addition, various electro-magneto-mechanical instability curves are drawn to examine the critical inflation of the tube actuator. In general, the developed model provides initial steps toward the modern actuator designs for applications where a precise control with high load-carrying capability of the actuator plays a significant role.

Modeling and analysis of an electro-pneumatic braided muscle actuator

2020 ◽  
pp. 1045389X2095362
Author(s):  
Deepak Kumar ◽  
Saswath Ghosh ◽  
Sitikantha Roy ◽  
Sushma Santapuri
Keyword(s):  
Continuum Mechanics ◽  
Input Voltage ◽  
Modeling And Analysis ◽  
Input Pressure ◽  
Static Modeling ◽  
Parametric Studies ◽  
The Impact ◽  
Special Case ◽  
Frictional Effects ◽  
Actuator Performance

The present study deals with static modeling and analysis of a novel electro-pneumatic braided muscle (EPBM) actuator. The EPBM actuator is a hybrid McKibben-type actuator, made of a dielectric polymeric bladder enclosed in a braided mesh sleeve. A continuum mechanics-based electromechanical model is developed to predict the response of the actuator for a combined pressure and voltage loading. The model also incorporates braid-to-braid frictional effects. The model agrees well with existing experimental results for the special case of zero input voltage. Parametric studies are subsequently performed for varying braid angle, input pressure, and voltage. Finally, the model is utilized to study the impact of fiber-reinforcement in the bladder on the actuator performance.

Analysis and Temperature Control of Hybrid Microcircuits

1973 ◽  
Vol 95 (4) ◽  
pp. 1048-1052 ◽  
Author(s):  
J. T. Pogson ◽  
J. L. Franklin
Keyword(s):  
Temperature Control ◽  
Thermal Modeling ◽  
Preliminary Design ◽  
Temperature Profiles ◽  
Modeling And Analysis ◽  
Parametric Studies ◽  
Temperature Levels ◽  
Typical Component ◽  
Circuit Designer ◽  
Component Temperature

The results of a study on thermal modeling and analysis of hybrid microcircuits are presented. Parametric studies covering typical component mounting methods, bonding agent materials, and component spacing are described. Temperature profiles of substrates, component temperatures, and thermal resistances are presented. It is shown that the use of moly tabs can significantly reduce component temperature levels. Additionally, it is shown that thermal modeling can greatly aid the circuit designer in the layout and preliminary design phases.

Torsional vibration of functionally graded carbon nanotube reinforced conical shells

2018 ◽  
Vol 25 (1) ◽  
pp. 41-52 ◽  
Author(s):  
Yaser Kiani
Keyword(s):  
Torsional Vibration ◽  
Conical Shell ◽  
Volume Fraction ◽  
Differential Quadrature Method ◽  
Functionally Graded ◽  
Mode Shapes ◽  
Coupled Equations ◽  
Parametric Studies ◽  
Torsional Frequency ◽  
Generalized Differential

AbstractThe present study deals with the free torsional vibration of a composite conical shell made of a polymeric matrix reinforced with carbon nanotubes (CNTs). Distribution of CNTs across the thickness of the conical shell may be uniform or functionally graded. Five different cases of functionally graded reinforcements are considered. First-order shear deformable shell theory compatible with the Donnell kinematic assumptions is used to establish the motion equations of the shell. These equations are two coupled equations which should be treated as an eigenvalue problem. The generalized differential quadrature method is used to obtain a numerical solution for the torsional frequency parameters and the associated mode shapes of the shell. After validating the results of this study for the cases of isotropic homogeneous cone and annular plates, parametric studies are carried out to analyze the influences of geometrical characteristics of the shell, volume fraction of CNTs, and grading profile of the CNTs. It is shown that volume fraction of CNTs is an important factor with regard to torsional frequencies of the shell; however, grading profile does not change the torsional frequencies significantly.

scholarly journals Effective electrodynamical parameters and microwave heating of radially heterogeneous pellets containing EAF dust and biochar

2021 ◽  
Vol 2015 (1) ◽  
pp. 012007
Author(s):  
Anton P Anzulevich ◽  
Leonid N Butko ◽  
Dmitry A Pavlov ◽  
Dmitry A Kalganov ◽  
Valentin A Tolkachev ◽  
...  
Keyword(s):  
Electromagnetic Field ◽  
Temperature Distribution ◽  
Volume Fraction ◽  
Effective Permittivity ◽  
Electric Arc ◽  
Arc Furnace ◽  
Eaf Dust ◽  
Permittivity And Permeability ◽  
Composite Mixture ◽  
Effective Medium Approach

Abstract In this work, we investigated the effect of microwave radiation with radially heterogeneous pellets consisting of electric arc furnace (EAF) dust and biochar. We reviewed the possible content of EAF dust in terms of permittivity and permeability of its components and calculated effective permittivity and permeability of EAF dust by an effective medium approach. Using obtained values we calculated dependencies of effective permittivity and permeability of EAF dust - biochar composite mixture on the volume fraction of EAF dust and conductivity of biochar. Taking into account these dependencies we simulated electromagnetic field and temperature distribution within pellet with a radial dependency of volume fraction of EAF dust and effective permittivity correspondingly.

scholarly journals EFFECTS OF GEOMETRIC VARIATIONS ON THE BUCKLING OF ARTERIES

2011 ◽  
Vol 03 (02) ◽  
pp. 385-406 ◽  
Author(s):  
PARAG DATIR ◽  
AVIONE Y. LEE ◽  
SHAWN D. LAMM ◽  
HAI-CHAO HAN
Keyword(s):  
Cross Sections ◽  
Critical Pressure ◽  
Arterial Wall ◽  
Mechanical Stability ◽  
Longitudinal Axis ◽  
Nonlinear Material ◽  
Mechanical Instability ◽  
Element Analysis ◽  
Buckling Behavior ◽  
Oval Cross Section

Arteries often demonstrate geometric variations such as elliptic and eccentric cross sections, stenosis, and tapering along the longitudinal axis. Effects of these variations on the mechanical stability of the arterial wall have not been investigated. The objective of this study was to determine the buckling behavior of arteries with elliptic, eccentric, stenotic, and tapered cross sections. The arterial wall was modeled as a homogeneous anisotropic nonlinear material. Finite element analysis was used to simulate the buckling process of these arteries under lumen pressure and axial stretch. Our results demonstrated that arteries with an oval cross section buckled in the short axis direction at lower critical pressures as compared to circular arteries. Eccentric cross sections, stenosis, and tapering also decreased the critical pressure. Stenosis led to dramatic pressure variations along the vessel and reduced the buckling pressure. In addition, tapering shifted the buckling deformation profile of the artery towards the distal end. We conclude that geometric variations reduce the critical pressure of arteries and thus make the arteries more prone to mechanical instability than circular cylindrical arteries. These results improve our understanding of the mechanical behavior of arteries.

Fiber-Reinforced Membrane Models of McKibben Actuators

2003 ◽  
Vol 70 (6) ◽  
pp. 853-859 ◽  
Author(s):  
W. Liu ◽  
C. R. Rahn
Keyword(s):  
Axial Load ◽  
Cylindrical Tube ◽  
Longitudinal Axis ◽  
Fiber Reinforced ◽  
Initial Shape ◽  
Fiber Angle ◽  
Inner Pressure ◽  
Membrane Models ◽  
Mckibben Actuators ◽  
Inextensible Fibers

A McKibben actuator consists of an internally pressurized elastic cylindrical tube covered by a shell braided with two families of inextensible fibers woven at equal and opposite angles to the longitudinal axis. Increasing internal pressure causes the actuator to expand radially and, due to the fiber constraint, contract longitudinally. This contraction provides a large force that can be used for robotic actuation. Based on large deformation membrane theory, the actuator is modeled as a fiber-reinforced cylinder with applied inner pressure and axial load. Given the initial shape, material parameters, axial load, and pressure, the analytical model predicts the deformed actuator shape, fiber angle, and fiber and membrane stresses. The analytical results show that for a long and thin actuator the deformed fiber angle approaches 54°44′ at infinite pressure. The actuator elongates and contracts for actuators with initial angles above and below 54°44′ degrees, respectively. For short and thick actuators with initial angles relatively close to 0 deg or 90 deg, however, a fiber angle boundary layer extends to the middle of the actuator, limiting possible extension or contraction. The calculated longitudinal strain and radius change match experimental results to within 5%.

Modeling and Analysis of a Small Diameter Pneumatic Boring Tool

1998 ◽  
Vol 120 (2) ◽  
pp. 292-298
Author(s):  
R. L. Collins ◽  
G. Prater ◽  
W. P. Hnat
Keyword(s):  
Computational Model ◽  
Nonlinear Differential Equations ◽  
Small Diameter ◽  
Control Valve ◽  
Pressure Control ◽  
Modeling And Analysis ◽  
Boring Tool ◽  
Parametric Studies ◽  
Pressure Control Valve ◽  
Spool Valve

This paper documents the development, solution, and application of a computational model for the dynamic response of a small diameter, pneumatic tool used for boring horizontal tunnels in the soil. The model consists of (i) the tool component kinematics and kinetics, (ii) mechanics of the tool and soil interactions, (iii) the compressible air dynamics, and (iv) the pressure control valve switching logic. The resulting model is represented by a set of coupled, sixth-order nonlinear differential equations. The boring tool design has several unique features, including dual pistonheads and a pilot-pressure actuated spool valve used to control the oscillatory piston. Implementation of these and other tool features in the computational model is discussed at length. The dynamic simulation and associated parametric studies establish the feasibility of the design for small diameter (25.4 mm) horizontal boring tools. Results for this design predict tunneling rates of about 60 meters/hr in a medium clay soil.

Imperfection sensitivity in the vibration behavior of functionally graded arches by considering microstructural defects

2018 ◽  
Vol 233 (8) ◽  
pp. 2763-2777 ◽  
Author(s):  
Mohammad Amir ◽  
Mohammad Talha
Keyword(s):  
Volume Fraction ◽  
Shear Deformation Theory ◽  
Functionally Graded ◽  
Power Law Distribution ◽  
Imperfection Sensitivity ◽  
Vibration Behavior ◽  
Microstructural Defects ◽  
Geometrical Imperfections ◽  
Parametric Studies ◽  
Benchmark Solutions

In this paper, imperfection sensitivity in the vibration behavior of functionally graded arches with microstructural defects (porosity) has been studied. The temperature-dependent material properties of functionally graded arches are assumed to vary continuously in the thickness direction by a simple power-law distribution in terms of the volume fractions of the constituents. The formulations are based on the Reddy’s higher order shear deformation theory using finite element method. Convergence and comparison studies have been performed to describe the efficacy of the present formulation. The obtained results have been compared with the limited available literature. The parametric studies have been performed to study the influence of the temperature rise, volume fraction index, and porosity index on the frequency response of the functionally graded arches. The effect of various modes of initial geometrical imperfections has also been examined. The obtained numerical results can be used as benchmark solutions for future researches in this field of study.

Exact Solution for Free Vibration and Buckling of Sandwich S-FGM Plates on Pasternak Elastic Foundation with Various Boundary Conditions

2019 ◽  
Vol 19 (03) ◽  
pp. 1950028 ◽  
Author(s):  
S. J. Singh ◽  
S. P. Harsha
Keyword(s):  
Free Vibration ◽  
Boundary Conditions ◽  
Elastic Foundation ◽  
Volume Fraction ◽  
Shear Deformation Theory ◽  
Functionally Graded ◽  
Load Parameter ◽  
Various Boundary Conditions ◽  
Pasternak Elastic Foundation ◽  
Parametric Studies

In the present study, free vibration and buckling characteristics of a sandwich functionally graded material (FGM) plate resting on the Pasternak elastic foundation have been investigated. The formulation is based on non-polynomial higher-order shear deformation theory with inverse hyperbolic shape function. A new modified sigmoid law is presented to compute the effective material properties of sandwich FGM plate. The governing equilibrium equations have been derived using Hamilton’s principle. Non-dimensional frequencies and critical buckling loads are evaluated by considering different boundary conditions based on admissible functions satisfying the desired primary and secondary variables. Comprehensive parametric studies have been performed to analyze the influence of geometric configuration, volume fraction exponent, elastic medium parameter, and non-dimensional load parameter on the non-dimensional frequency and critical buckling load. These parametric studies have been done for various boundary conditions and different configurations of the sandwich plate. The computed results can be used as a benchmark for future comparison of sandwich S-FGM plates.

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