scholarly journals A FEM-Experimental Approach for the Development of a Conceptual Linear Actuator Based on Tendril’s Free Coiling

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Luca Cortese ◽  
Selena Milanovic ◽  
Renato Vidoni
Keyword(s):  
Experimental Approach ◽  
Experimental Tests ◽  
Nickel Titanium ◽  
Linear Actuator ◽  
The Finite Element Method ◽  
Actual Performance ◽  
Suitable Material ◽  
Working Principle ◽  
Set Up ◽  
Prototype Design

Within the vastness of the plant species, certain living systems show tendril structures whose motion is of particular interest for biomimetic engineers. Tendrils sense and coil around suitable grips, and by shortening in length, they erect the remaining plant body. To achieve contraction, tendrils rotate along their main axis and shift from a linear to a double-spring geometry. This phenomenon is denoted as the free-coiling phase. In this work, with the aim of understanding the fundamentals of the mechanics behind the free coiling, a reverse-engineering approach based on the finite element method was firstly applied. The model consisted of an elongated cylinder with suitable material properties, boundary, and loading conditions, in order to reproduce the kinematics of the tendril. The simulation succeeded in mimicking coiling faithfully and was therefore used to validate a tentative linear actuator model based on the plant’s working principle. More in detail, exploiting shape memory alloy materials to obtain large reversible deformations, the main tendril features were implemented into a nickel-titanium spring-based testing model. The results of the experimental tests confirmed the feasibility of the idea in terms of both functioning principles and actual performance. It can be concluded that the final set-up can be used as a base for a prototype design of a new kind of a linear actuator.

scholarly journals Numerical Evaluation of Structural Safety of Linear Actuator for Flap Control of Aircraft Based on Airworthiness Standard

Aerospace ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 104
Author(s):  
Dong-Hyeop Kim ◽  
Young-Cheol Kim ◽  
Sang-Woo Kim
Keyword(s):  
Numerical Analysis ◽  
Analytical Method ◽  
Safety Evaluation ◽  
Experimental Tests ◽  
Structural Safety ◽  
Linear Actuator ◽  
The Finite Element Method ◽  
Margin Of Safety ◽  
Verification Methodology ◽  
The Given

Airworthiness standards of Korea recommend verifying structural safety by experimental tests and analytical methods, owing to the development of analysis technology. In this study, we propose a methodology to verify the structural safety of aircraft components based on airworthiness requirements using an analytical method. The structural safety and fatigue integrity of a linear actuator for flap control of aircraft was evaluated through numerical analysis. The static and fatigue analyses for the given loads obtained from the multibody dynamics analysis were performed using the finite element method. Subsequently, the margin of safety and vulnerable area were acquired and the feasibility of the structural safety evaluation using the analytical method was confirmed. The proposed numerical analysis method in this study can be adopted as an analytical verification methodology for the airworthiness standards of civilian aircraft in Korea.

scholarly journals Large-scale triaxial and box testing on railroad ballast: a review

2019 ◽  
Vol 1 (12) ◽  
Author(s):  
Yahia Alabbasi ◽  
Mohammed Hussein
Keyword(s):  
Mechanical Behavior ◽  
Large Scale ◽  
Experimental Approach ◽  
Load Condition ◽  
Experimental Tests ◽  
Basic Element ◽  
Transportation Systems ◽  
Extensive Literature ◽  
Railway Transportation ◽  
Set Up

Abstract The use of railway transportation systems has been increased throughout the years. The conventional ballasted tracks have been used widely in many countries around the world. Ballast material is the basic element of ballasted tracks. Ballast degrades and deforms after service. Therefore, periodical ballast maintenance is needed which is a cost and time expensive activity. Understanding ballast mechanical behavior leads to better design and efficient maintenance. From the literature, experimental approach is used to understand the mechanical behavior of railroad ballast. Traditional experimental tests provide inaccurate results due to the large ballast particle size with relative to sample size. Researchers used large scale triaxial and box tests extensively to understand the mechanical behavior of railroad ballast. The target of this paper is to present a concise review of the extensive literature presented on the mechanical behavior of railroad ballast using large scale triaxial and box testing. It discusses the various aspects of large-scale equipment such as apparatus’ set-up, size, material and shape, simulated load condition and test purpose. It presents the key findings of the large-scale triaxial and box tests in understanding ballast mechanical behavior.

scholarly journals Parameters Identification of the Anand Material Model for 3D Printed Structures

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 587
Author(s):  
Martin Fusek ◽  
Zbyněk Paška ◽  
Jaroslav Rojíček ◽  
František Fojtík
Keyword(s):  
Plastic Material ◽  
Acrylonitrile Butadiene Styrene ◽  
Experimental Tests ◽  
Material Model ◽  
Anisotropic Behavior ◽  
Suitable Material ◽  
Material Parameters ◽  
Indentation Tests ◽  
Set Up ◽  
Future Work

Currently, there is an increasing use of machine parts manufactured using 3D printing technology. For the numerical prediction of the behavior of such printed parts, it is necessary to choose a suitable material model and the corresponding material parameters. This paper focuses on the determination of material parameters of the Anand material model for acrylonitrile butadiene styrene (ABS-M30) material. Material parameters were determined using the genetic algorithm (GA) method using finite element method (FEM) calculations. The FEM simulations were subsequently adjusted to experimental tests carried out to achieve the possible best agreement. Several experimental tensile and indentation tests were performed. The tests were set up in such a way that the relaxation and creep behaviors were at least partially captured. Experimental tests were performed at temperatures of 23 °C, 44 °C, 60 °C, and 80 °C. The results obtained suggest that the Anand material model can also be used for ABS-M30 plastic material, but only if the goal is not to detect anisotropic behavior. Future work will focus on the search for a suitable material model that would be able to capture the anisotropic behavior of printed plastic materials.

scholarly journals Detection capability of Migdal effect for argon and xenon nuclei with position sensitive gaseous detectors

2020 ◽  
Author(s):  
Kiseki D Nakamura ◽  
Kentaro Miuchi ◽  
Shingo Kazama ◽  
Yutaro Shoji ◽  
Masahiro Ibe ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Experimental Approach ◽  
Isotope Separation ◽  
Mass Region ◽  
Background Rate ◽  
Argon Gas ◽  
Low Mass ◽  
Position Sensitive ◽  
Set Up ◽  
Direct Dark Matter

Abstract Migdal effect is attracting interests because of the potential to enhance the sensitivities of direct dark matter searches to the low mass region. In spite of its great importance, the Migdal effect has not been experimentally observed yet. A realistic experimental approach towards the first observation of the Migdal effect in the neutron scattering was studied with Monte Carlo simulations. In this study, potential background rate was studied together with the event rate of the Migdal effect by a neutron source. It was found that a table-top sized ~ (30cm)3 position-sensitive gaseous detector filled with argon or xenon target gas can detect characteristic signatures of the Migdal effect with sufficient rates (O(102 ~ 103) events/day). A simulation result of a simple experimental set-up showed two significant background sources, namely the intrinsic neutrons and the neutron induced gamma-rays. It is found that the intrinsic neutron background rate for the argon gas is acceptable level and some future study for the reduction of the gamma-rays from the laboratory would make the observation of the Migdal effect possible. The background for the xenon gas, on the other hand, is found to be much more serious than for the argon gas. Future works on the isotope separation as well as the reduction of the gamma-rays from the detector and laboratory will be needed before the Migdal effect observation for xenon gas case.

scholarly journals Concept for controlled adjustment of residual stress states in semi-finished products by gradation extrusion

2021 ◽  
Author(s):  
René Selbmann ◽  
Markus Baumann ◽  
Mateus Dobecki ◽  
Markus Bergmann ◽  
Verena Kräusel ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Experimental Tests ◽  
Residual Stress Distribution ◽  
Forming Process ◽  
Compressive Stresses ◽  
Energy Consuming ◽  
Stress States ◽  
Set Up ◽  
Time And Energy

AbstractThe residual stress distribution in extruded components and wires after a conventional forming process is frequently unfavourable for subsequent processes, such as bending operations. High tensile residual stresses typically occur near the surface of the wire and thus limit further processability of the material. Additional heat treatment operations or shot peening are often inserted to influence the residual stress distribution in the material after conventional manufacturing. This is time and energy consuming. The research presented in this paper contains an approach to influence the residual stress distribution by modifying the forming process for wire-like applications. The aim of this process is to lower the resulting tensile stress levels near the surface or even to generate compressive stresses. To achieve these residual compressive stresses, special forming elements are integrated in the dies. These modifications in the forming zone have a significant influence on process properties, such as degree of deformation and deformation direction, but typically have no influence on the diameter of the product geometry. In the present paper, the theoretical approach is described, as well as the model set-up, the FE-simulation and the results of the experimental tests. The characterization of the residual stress states in the specimen was carried out by X-ray diffraction using the sin2Ψ method.

Knowledge-Based System for Supporting the Design of a Plate-Press

2012 ◽  
Vol 12 (2) ◽  
Author(s):  
David Potočnik ◽  
Miran Ulbin ◽  
Bojan Dolšak
Keyword(s):  
Material Selection ◽  
Compressive Load ◽  
The Finite Element Method ◽  
Design Quality ◽  
Suitable Material ◽  
Improve Design ◽  
Knowledge Based System ◽  
Cad System ◽  
Design Time ◽  
Knowledge Based

This paper presents a knowledge-based system capable of giving the designer quality support when making decisions from the aspect of modeling the reinforcement of a plate-press within a position of maximum compressive load, and by choosing suitable material for the plate. Based on the selected combination of reinforcement and material, this system acquaints the user with the size and position of the largest comparative stress, and the greatest nodal displacement in the load-direction. This system operates based on the implemented knowledge of experts in the execution of design, material selection, and numerical analysis based on the finite-element method (FEM), which was written with the help of parameters within the knowledge-base of the CATIA V5 CAD-system. Using this system gives the user an opportunity to reach conclusions that are crucial for designing a plate-press or pressure-loaded die-elements, in general. The results reveal that the system can dramatically shorten design time and improve design quality in comparison to manual design process.

Actual Discharge on Venturimeter - A Literature

2021 ◽  
pp. 1-4
Author(s):  
Amit Rakshit ◽  
Sumana Ghosh
Keyword(s):  
Automotive Industry ◽  
Air Distribution ◽  
Flow Lines ◽  
Discharge Coefficients ◽  
Working Principle ◽  
Set Up

Venturi meter is a device which is used for measuring the rate of flow of fluid flowing through the pipes. The applications of these are found in various fields like Water House Department, Aviation, Automotive, Chemical, Petro-chemical industries, etc. In automotive industry venturimeter is used to measure the fuel and air distribution in carburetor. Similarly, in the water houses, venturimeter device is used to calculate the velocity of flow in the pipelines [1]. In this paper we have to discuss about the working principle and set up the study of experimental calculations on venturimeter. In the present paper, an attempt was made to study a computational device of a venturimeter, which can be used as an efficient and easy means for predicting the discharge coefficients for the flow lines. Keywords: Venturi meter; Discharge; Heads; Co-efficient of Discharge

Experimental Analysis of Velocity Fields in Hot Extrusion of Aluminium Alloy 6351

2011 ◽  
Vol 491 ◽  
pp. 145-150 ◽  
Author(s):  
Marcelo Martins ◽  
Sérgio Tonini Button ◽  
José Divo Bressan
Keyword(s):  
Metal Forming ◽  
Internal Flow ◽  
Hot Extrusion ◽  
Experimental Tests ◽  
Velocity Fields ◽  
The Finite Element Method ◽  
Forming Process ◽  
Complex Shapes ◽  
Metal Forming Process ◽  
Volume Method

Hot extrusion is a metal forming process with a huge importance in the manufacturing of long metallic bars with complex shapes, and because of this, academics and industries are especially interested in better understanding how metal flows during the process. In order to have a reliable computational tool that can help to solve and to obtain material internal flow, experimental tests and numerical simulation with the finite element method were carried out to obtain results of the velocity fields generated in hot direct extrusion of aluminum billets (aluminum alloy 6351). The experimental results of the velocity field will be used to validate a computational code based on the finite volume method.

scholarly journals NUMERICAL ANALYSIS OF CORRUGATED STEEL PLATE BRIDGE WITH REINFORCED CONCRETE RELIEVING SLAB

2015 ◽  
Vol 22 (5) ◽  
pp. 585-596 ◽  
Author(s):  
Damian BEBEN ◽  
Adam STRYCZEK
Keyword(s):  
Reinforced Concrete ◽  
Numerical Analysis ◽  
Steel Plate ◽  
Numerical Models ◽  
Experimental Tests ◽  
Bridge Engineering ◽  
Steel Plates ◽  
The Finite Element Method ◽  
Calculation Results ◽  
Rc Slab

The paper presents a numerical analysis of corrugated steel plate (CSP) bridge with reinforced concrete (RC) relieving slab under static loads. Calculations were made based on the finite element method using Abaqus software. Two computation models were used; in the first one, RC slab was used, and the other was without it. The effect of RC slab to deformations of CSP shell was determined. Comparing the computational results from two numerical models, it can be concluded that when the relieving slab is applied, substantial reductions in displacements, stresses, bending mo­ments and axial thrusts are achieved. Relative reductions of displacements were in the range of 53–66%, and stresses of 73–82%. Maximum displacements and bending moments were obtained at the shell crown, and maximum stresses and axial thrusts at the quarter points. The calculation results were also compared to the values from experimental tests. The course of computed displacements and stresses is similar to those obtained from experimental tests, although the absolute values were generally higher than the measured ones. Results of numerical analyses can be useful for bridge engineering, with particular regard to bridges and culverts made from corrugated steel plates for the range of necessity of using additional relieving elements.

scholarly journals Dimensioning a Call Center: Simulation or Queue Theory?

2009 ◽  
Vol 2 (2) ◽  
pp. 34 ◽  
Author(s):  
Marco Aurélio Carino Bouzada
Keyword(s):  
Analytical Method ◽  
Analytical Methods ◽  
Call Center ◽  
Experimental Approach ◽  
Call Centers ◽  
Experimental Methods ◽  
New Approach ◽  
Alternative Methodology ◽  
Queue Theory ◽  
Set Up

The objective of this paper is to establish a dichotomy - opposing analytical methods (such as Queue Theory) to experimental methods (such as Simulation) and discussing their adequateness to complex operations - set up in the matter of dimensioning the handling capacity of a large brazilian call centers company. The literature related to the application of such methods at call centers is reviewed, and the way the question is treated nowadays by the company is described. Then an experimental approach is suggested to be implemented as an alternative methodology to deal with the issue, instead of the analytical method in use. The results obtained are used to justify the adequacy of the experimental approach to the modern call centers operation, as long as it is possible to have the model closer to reality. The main implication points to a better understanding of the operation achieved with the new approach

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