A Theoretical Model for High Rate Electrochemical Machining

1973 ◽  
Vol 95 (4) ◽  
pp. 1003-1008 ◽  
Author(s):  
S. P. Loutrel ◽  
N. H. Cook
Keyword(s):  
Theoretical Model ◽  
Electrochemical Machining ◽  
Experimental Results ◽  
High Rate ◽  
Simplified Model ◽  
Complex Geometries ◽  
Machining Parameters ◽  
Computer Solution ◽  
Cutting Zone ◽  
Current Densities

A theoretical model for the process occurring in the cutting zone is developed. A computer solution to apply the model to an actual ECM situation is outlined. A simplified model and computer solution is described which can be used to predict machining parameters for complex geometries. For both models good correlation of experimental results is found in most cases. The application of classical electrochemistry to conditions where extreme current densities (5800 amps/cm2) are encountered is discussed.

High Rate Electrochemical Machining

1973 ◽  
Vol 95 (4) ◽  
pp. 992-996 ◽  
Author(s):  
S. P. Loutrel ◽  
N. H. Cook
Keyword(s):  
Theoretical Model ◽  
Ion Mobility ◽  
Electrochemical Machining ◽  
High Flow ◽  
High Rate ◽  
Aqueous Sodium ◽  
Electrolyte Conductivity ◽  
High Temperature And Pressure ◽  
Temperature And Pressure ◽  
Rate Limiting

This is the first of three papers on high rate Electrochemical Machining. Feed rate limiting mechanisms are discussed along with qualitative predictions. Methods of increasing feed rates are studied theoretically and experimentally. The use of high supply voltages (118 volts) high electrolyte pressures (330 bars (4800 psi)) and high flow velocities (192 M/sec) when machining iron in aqueous sodium chloride electrolyte led to feed rates of 10.8 cm/min (4.25 in/min). The following two papers will discuss a theoretical model of the ECM process and present high temperature and pressure electrolyte conductivity and ion mobility.

Sodium Chloride Electrolyte Data at High Temperatures and Pressures

1973 ◽  
Vol 95 (4) ◽  
pp. 997-1002 ◽  
Author(s):  
S. P. Loutrel ◽  
N. H. Cook
Keyword(s):  
Theoretical Model ◽  
Sodium Chloride ◽  
Mathematical Models ◽  
High Temperatures ◽  
High Pressures ◽  
Electrochemical Machining ◽  
Simple Calculation ◽  
High Rate ◽  
Chloride Electrolyte ◽  
Experimental Apparatus

Electrolyte conductivities were measured and ion mobilities were calculated for use in applying the theoretical model for high rate Electrochemical Machining which was described in two other papers. The ions treated are Na+, Cl−, Fe++, and OH−. Mathematical models are derived to allow simple calculation of ion mobilities including the case where mixtures of ions are present. The effect of high temperatures (on the order of 200 deg C) and high pressures (on the order of 220 bars) is emphasized. The experimental apparatus used in making these measurements is also described.

scholarly journals The compressive behavior of cement mortar with the addition of nano metakaolin

2018 ◽  
Vol 8 ◽  
pp. 184798041875559 ◽  
Author(s):  
Guo Xiaoyu ◽  
Fan Yingfang ◽  
Luan Haiyang
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Theoretical Model ◽  
Cement Mortar ◽  
Experimental Results ◽  
Mineral Admixtures ◽  
Simplified Model ◽  
Influence Coefficient ◽  
Mechanical Index ◽  
Compressive Behavior

Elastic modulus is an important mechanical index for the cement-based materials, which has a significant effect on the static and dynamic response of the concrete structure. To investigate the compressive behavior of nano metakaolin cement mortar, the effects of dispersion conditions, water to binder ratios, and mineral admixtures on the compressive strength of nano metakaolin cement mortar were examined. The elastic modulus of nano metakaolin cement mortar under different water to binder ratios and mineral admixtures was obtained. Based on the theory of micromechanics of composite materials, a theoretical model was deduced to calculate elastic modulus of nano metakaolin cement mortar. Based on the experimental results, an influence coefficient was introduced into simplified model to estimate the elastic modulus of nano metakaolin cement mortar. The results demonstrate that the application of ultrasonic dispersion and long-duration dispersion time (no more than 15 min) can effectively improve the compressive strength of nano metakaolin cement mortar. Compressive strength of nano metakaolin cement mortar mixed with ground granulated blast furnace slag, fly ash, and attapulgite clay is 33.38%, 17.65%, and 6.45% higher than that of the ordinary mortar, respectively. Compared with the experimental results, the calculated error of theoretical model is no more than 5%, while the calculated error of the simplified model is no more than 10%.

Actuation and dynamic mechanical characteristics of a core free flat dielectric electro-active polymer soft actuator

2020 ◽  
Vol 14 (4) ◽  
pp. 7396-7404
Author(s):  
Abdul Malek Abdul Wahab ◽  
Emiliano Rustighi ◽  
Zainudin A.
Keyword(s):  
Theoretical Model ◽  
Resonance Frequency ◽  
Dynamic Testing ◽  
Experimental Results ◽  
Percentage Error ◽  
Initial Tension ◽  
Average Percentage ◽  
Soft Actuator ◽  
Average Percentage Error ◽  
Mechanical Dynamics

Various complex shapes of dielectric electro-active polymer (DEAP) actuator have been promoted for several types of applications. In this study, the actuation and mechanical dynamics characteristics of a new core free flat DEAP soft actuator were investigated. This actuator was developed by Danfoss PolyPower. DC voltage of up to 2000 V was supplied for identifying the actuation characteristics of the actuator and compare with the existing formula. The operational frequency of the actuator was determined by dynamic testing. Then, the soft actuator has been modelled as a uniform bar rigidly fixed at one end and attached to mass at another end. Results from the theoretical model were compared with the experimental results. It was found that the deformation of the current actuator was quadratic proportional to the voltage supplied. It was found that experimental results and theory were not in good agreement for low and high voltage with average percentage error are 104% and 20.7%, respectively. The resonance frequency of the actuator was near 14 Hz. Mass of load added, inhomogeneity and initial tension significantly affected the resonance frequency of the soft actuator. The experimental results were consistent with the theoretical model at zero load. However, due to inhomogeneity, the frequency response function’s plot underlines a poor prediction where the theoretical calculation was far from experimental results as values of load increasing with the average percentage error 15.7%. Hence, it shows the proposed analytical procedure not suitable to provide accurate natural frequency for the DEAP soft actuator.

scholarly journals A Simplified Model Applied to the Barite Sag and Fluid Flow in Drilling Muds: Simulation and Experimental Results

2017 ◽  
Vol 72 (4) ◽  
pp. 23 ◽  
Author(s):  
José Messias Ribeiro ◽  
Felipe Moreira Eler ◽  
André Leibson Martins ◽  
Cláudia Miriam Scheid ◽  
Luís Américo Calçada ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Experimental Results ◽  
Simplified Model ◽  
Drilling Muds

How to Deal With Death: An Empirical Path Analysis of a Simplified Model of Death Anxiety

2018 ◽  
Vol 82 (2) ◽  
pp. 261-277
Author(s):  
Vera Surall ◽  
Inga Steppacher
Keyword(s):  
Life Satisfaction ◽  
Theoretical Model ◽  
Path Analysis ◽  
Mediation Analysis ◽  
Empirical Data ◽  
Death Anxiety ◽  
Demographic Variables ◽  
Model Fit ◽  
Simplified Model ◽  
Death Acceptance

How anxious are you about dying? According to Tomer and Eliason, this depends on various personal circumstances, which they identified in their model on death anxiety. This study aims to verify various aspects of Tomer and Eliason’s theoretical model. We therefore collected data from 652 German participants about demographic variables, religiosity, life satisfaction, death acceptance, and death anxiety. We then conducted a path analysis in order to verify whether the empirical data supported the theoretical model. Our results demonstrate a very good model fit, indicating that the analyzed model is valid and can be maintained. Further mediation analysis demonstrates the specific relations of variables within the model and their influence on death anxiety.

scholarly journals Investigation of thermal conductivity of single-wall carbon nanotubes

2011 ◽  
Vol 15 (2) ◽  
pp. 565-570 ◽  
Author(s):  
Mahmoud Jafari ◽  
Majid Vaezzadeh ◽  
Momhamad Mansouri ◽  
Abazar Hajnorouzi
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Theoretical Model ◽  
Potential Energy ◽  
Experimental Results ◽  
Single Wall Carbon Nanotubes ◽  
Lattice Vibrations ◽  
Single Wall Carbon ◽  
Thermal Potential ◽  
Conductivity Behavior

In this paper, the thermal conductivity of Single-wall carbon nanotubes (SWCNTs) is determined by lattice vibrations (phonons) and free elections. The thermal conductivity of SWCNTs is modeled up to 8-300 K and the observed deviations in K-T figures of SWCNTs are explained in terms of phonon vibrations models. An suitable theoretical model is shown for thermal conductivity behavior with respect to temperature and is generalized for experimental results. This model enables us to calculate thermal conductivity SWNTs and Thermal Potential Energy (TPE).

scholarly journals Research on the Influencing Factors of "Scale Veins" of Single Point Incremental Forming Workpieces Surface

2015 ◽  
Vol 9 (1) ◽  
pp. 1025-1032
Author(s):  
Shi Pengtao ◽  
Li Yan ◽  
Yang Mingshun ◽  
Yao Zimeng
Keyword(s):  
Surface Quality ◽  
Incremental Forming ◽  
Single Point ◽  
Spindle Speed ◽  
Experimental Results ◽  
Feed Speed ◽  
Single Point Incremental Forming ◽  
Machining Parameters ◽  
The Mathematical Model

To furthermore optimize the machining parameters and improve the surface quality of the workpieces manufactured by single point incremental forming method, the formation mechanism of the sacle veins on the metal incremental froming workpieces was studied through experiment method. The influence principle of the spindle speed, the feed speed and the material of tip of tools on the length of scale veins was obtained through analyzing the experimental results and building the mathematical model among the length of scale veins were feed speed and spindle speed through measuring the roughness of surfaces and observing the appearance of the forming workpieces. The experimental results showed that, the spindle speed, the feed speed and the material of tool tips have a significant effect on the scale veins formation on the surface of forming workpieces. Therefore, an appropriate group of spindle speed and feed speed can reduce the effect of scale veins on the roughness of single point incremental forming workpieces and furthermore improve the surface quality of forming workpieces.

Theoretical Model for Interfacial Nonlinear Bond Softening Behavior between Embedded Steel and HSHPC

2007 ◽  
Vol 348-349 ◽  
pp. 845-848
Author(s):  
Shan Suo Zheng ◽  
Lei Li ◽  
Guo Zhuan Deng ◽  
Shun Li Che ◽  
Wei Zhao
Keyword(s):  
Theoretical Model ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Nonlinear Process ◽  
Experimental Results ◽  
Interfacial Bond ◽  
Bond Slip ◽  
Softening Behavior ◽  
Bond Softening

The latest experimental study on steel reinforced high strength and high performance concrete (SRHSHPC) specimens shows that there exists interfacial bond softening phenomenon between embedded steel and high strength and high performance concrete (HSHPC), and it makes the shear transfer capacity between shaped steel and HSHPC be progressively reduced. To predict failure load in design, a theoretical model for interfacial bond softening behavior is required. As interfacial bond softening behavior is a nonlinear process involving material properties, it can be analyzed once the relation of interfacial bond stress (τ ) and slippage ( s ) is known. In this paper, the mechanism of interfacial bond-slip is studied, thus a simplified τ − s relation including ascending and descending parts is proposed and employed to analyze the interfacial nonlinear bond-slip process. Based on the interfacial equilibrium between steel and HSHPC as well as the τ − s relation, the basic governing equations in both softened region and elastic region are established and solved for steel strain or stress. At last, the application of the model is verified through comparison with experimental results. The calculating results of the model are found to be in good agreement with experimental results, showing that the model can describe the bond-slip process in real material systems.

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