Modeling the Effects of Mixed Flowing Gas (MFG) Corrosion and Stress Relaxation on Contact Interface Resistance

1993 ◽  
Vol 115 (4) ◽  
pp. 404-409 ◽  
Author(s):  
Shrikar Bhagath ◽  
Michael G. Pecht
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Stress Relaxation ◽  
Contact Resistance ◽  
Time Dependence ◽  
Normal Force ◽  
Operating Temperature ◽  
Contact Interface ◽  
Time Stress ◽  
Over Time

This paper presents the development of an initial, “first-cut”, mathematical model for the prediction of electrical interface reliability trends. The model pertains to gold plated contacts subject to loss of normal force and environmental corrosion with time. Stress relaxation over time and temperature in the base metal of the contact is accounted for. Utilizing the results of Mixed Flowing Gas (MFG) tests, the model can be used to estimate the statistical contact resistance at a particular load (normal force), aging and operating temperature in the class II and III environments. An attempt is made to correlate experimental data with the classical Holm’s equation and to introduce time dependence into the equation. Further work is proposed to correlate results with experimental connector performance data.

scholarly journals Development of High-Sensitivity Pressure Sensor with On-chip Differential Transistor Amplifier

2021 ◽  
Author(s):  
Mikhail
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Pressure Sensor ◽  
Feedback Loop ◽  
Operating Temperature ◽  
High Sensitivity ◽  
Electrical Circuit ◽  
Negative Feedback Loop ◽  
On Chip ◽  
Operating Temperature Range

A mathematical model of a high-sensitivity pressure sensor with a novel electrical circuit utilizing a piezosensitive transistor differential amplifier with negative feedback loop is presented. Circuits utilizing differential transistor amplifiers based on vertical n-p-n and lateral p-n-p transistors are analyzed and optimized for sensitivity to pressure and stability of output signal in operating temperature range. Parameters of fabrication process necessary for modeling of I–V characteristics of transistors are discussed. The results of the model are sufficiently close to the experimental data.

scholarly journals Development of High-Sensitivity Pressure Sensor with On-chip Differential Transistor Amplifier

2021 ◽  
Author(s):  
Mikhail Basov
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Pressure Sensor ◽  
Feedback Loop ◽  
Operating Temperature ◽  
High Sensitivity ◽  
Electrical Circuit ◽  
Negative Feedback Loop ◽  
On Chip ◽  
Operating Temperature Range

<p>A mathematical model of a high-sensitivity pressure sensor with a novel electrical circuit utilizing piezosensitive transistor differential amplifier with negative feedback loop (PDA-NFL) is presented. Circuits utilizing differential transistor amplifiers based on vertical n-p-n and lateral p-n-p transistors are analyzed and optimized for sensitivity to pressure and stability of output signal in operating temperature range. Parameters of fabrication process necessary for modeling of I-V characteristics of transistors are discussed. The results of the model are sufficiently close to the experimental data.</p><br>

Results of Studying Strain Relaxation in Steel 25Kh17N2B-Sh (25Х17Н2Б-Ш) and Copper М1 Using Annular Samples of Equal Bending Resistance

2021 ◽  
pp. 59-71
Author(s):  
A.V. Proskurin ◽  
S.P. Sayun
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Plastic Deformation ◽  
Stress Relaxation ◽  
Control Sample ◽  
Calculated Data ◽  
Correct Operation ◽  
Preliminary Plastic Deformation ◽  
Bending Resistance ◽  
Annealed Copper

The paper introduces the research into stress relaxation of corrosion-resistant steel 25Kh17N2B-Sh (25Х17Н2Б-Ш) at temperatures of 20 and 100 °C, annealed copper M1 of two types --- soft and subjected to preliminary plastic deformation --- at a temperature of 20 °C, used in the manufacture of parts for butt joints of high-pressure pipelines. The research was carried out on annular samples of equal bending resistance according to the method of Oding. The study shows the action of temperature on the rate of stress relaxation in steel 25Kh17N2B-Sh (25Х17Н2Б-Ш), as well as the effect of preliminary plastic deformation of annealed copper on its relaxation characteristics, which is especially noticeable in the first hours after loading. As a result of the analysis of experimental data and by means of nonlinear regression, we determined the numerical values of the parameters of the equations used to describe the process of stress relaxation. Using the obtained expressions, we calculated and plotted the curves of stress relaxation in the materials under study. Furthermore, we compared the stress values calculated using the obtained relaxation model for steel 25Kh17N2B-Sh (25Х17Н2Б-Ш) at a temperature of 20 °C with the results of stress relaxation of a control sample from the same material, the test results of which were not used in the development of a mathematical model. The calculated data showed good similarity with the experimental data obtained on the test sample, which indicates the correct operation of the mathematical model

scholarly journals Mathematical model of cavitation under the influence of a single stretching pulse

2019 ◽  
Vol 27 (1) ◽  
pp. 49-59
Author(s):  
Nikolay Yu Kravchenko ◽  
Dmitry S Kulyabov
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Time Dependence ◽  
Vapor Phase ◽  
Negative Pressure ◽  
Carrier Phase ◽  
Pressure Pulse ◽  
Cavitation Bubbles ◽  
Temperature And Pressure ◽  
Good Agreement

This paper describes the created mathematical model that allows you to explore the dynamics of cavitation bubbles under the influence of a single negative pressure pulse. The time dependence and coordinates of the parameters of the carrier phase, the temperature and pressure of the vapor phase, the concentration and size of the bubbles are determined numerically. It is concluded that the model created gives a good agreement between the calculated and experimental data.

scholarly journals Development of High-Sensitivity Pressure Sensor with On-chip Differential Transistor Amplifier

2021 ◽  
Author(s):  
Mikhail Basov
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Pressure Sensor ◽  
Feedback Loop ◽  
Operating Temperature ◽  
High Sensitivity ◽  
Electrical Circuit ◽  
Negative Feedback Loop ◽  
On Chip ◽  
Operating Temperature Range

<p>A mathematical model of a high-sensitivity pressure sensor with a novel electrical circuit utilizing piezosensitive transistor differential amplifier with negative feedback loop (PDA-NFL) is presented. Circuits utilizing differential transistor amplifiers based on vertical n-p-n and lateral p-n-p transistors are analyzed and optimized for sensitivity to pressure and stability of output signal in operating temperature range. Parameters of fabrication process necessary for modeling of I-V characteristics of transistors are discussed. The results of the model are sufficiently close to the experimental data.</p><br>

The substantiation of the formalized estimation of effectiveness of technological and production systems

2018 ◽  
Vol 15 (1) ◽  
pp. 169-181
Author(s):  
M. I. Sidorov ◽  
М. Е. Stavrovsky ◽  
V. V. Irogov ◽  
E. S. Yurtsev
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Production Systems ◽  
Van Der Pol

Using the example of van der Pol developed a mathematical model of frictional self-oscillations in topochemically kinetics. Marked qualitative correspondence of the results of calculation performed using the experimental data of researchers.

scholarly journals Exhaust Noise Reduction by Application of Expanded Collecting System in Pneumatic Tools and Machines

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1592
Author(s):  
Dominik Gryboś ◽  
Jacek S. Leszczyński ◽  
Dorota Czopek ◽  
Jerzy Wiciak
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Noise Reduction ◽  
Sound Pressure ◽  
Acoustic Pressure ◽  
Pressure Level ◽  
Computational Results ◽  
Noise Measurements ◽  
Exhaust Noise ◽  
Collecting System

In this paper, we demonstrate how to reduce the noise level of expanded air from pneumatic tools. Instead of a muffler, we propose the expanded collecting system, where the air expands through the pneumatic tube and expansion collector. We have elaborated a mathematical model which illustrates the dynamics of the air flow, as well as the acoustic pressure at the end of the tube. The computational results were compared with experimental data to check the air dynamics and sound pressure. Moreover, the study presents the methodology of noise measurement generated in a pneumatic screwdriver in a quiet back room and on a window-fitting stand in a production hall. In addition, we have performed noise measurements for the pneumatic screwdriver and the pneumatic screwdriver on an industrial scale. These measurements prove the noise reduction of the pneumatic tools when the expanded collecting system is used. When the expanded collecting system was applied to the screwdriver, the measured Sound Pressure Level (SPL) decreased from 87 to 80 dB(A).

Modal Analysis of the Axial Compressor Blade: Advanced Time-Dependent Electronic Interferometry and Finite Element Method

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Mykhaylo Tkach ◽  
Serhii Morhun ◽  
Yuri Zolotoy ◽  
Irina Zhuk
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Finite Element ◽  
High Reliability ◽  
Axial Compressor ◽  
Time Dependent ◽  
Experimental Setup ◽  
Vibration Modes ◽  
Compressor Blades ◽  
Isoparametric Finite Element

AbstractNatural frequencies and vibration modes of axial compressor blades are investigated. A refined mathematical model based on the usage of an eight-nodal curvilinear isoparametric finite element was applied. The verification of the model is carried out by finding the frequencies and vibration modes of a smooth cylindrical shell and comparing them with experimental data. A high-precision experimental setup based on an advanced method of time-dependent electronic interferometry was developed for this aim. Thus, the objective of the study is to verify the adequacy of the refined mathematical model by means of the advanced time-dependent electronic interferometry experimental method. The divergence of the results of frequency measurements between numerical calculations and experimental data does not exceed 5 % that indicates the adequacy and high reliability of the developed mathematical model. The developed mathematical model and experimental setup can be used later in the study of blades with more complex geometric and strength characteristics or in cases when the real boundary conditions or mechanical characteristics of material are uncertain.

scholarly journals Modelling time efficiency of cobot-supported kit preparation

2019 ◽  
Vol 106 (5-6) ◽  
pp. 2227-2241 ◽  
Author(s):  
Patrik Fager ◽  
Martina Calzavara ◽  
Fabio Sgarbossa
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Cycle Time ◽  
Laboratory Experiments ◽  
Spare Parts ◽  
Batch Preparation ◽  
Assembly Quality ◽  
Numerical Example ◽  
Business To Business ◽  
Support Time

AbstractKitting – meaning to supply assembly with components in presorted kits – is widely seen as beneficial for assembly quality and efficiency when there is a multitude of component variants. However, the process by which kits are prepared – the kit preparation – is labour-intensive, and kit errors are problematic at assembly processes. The use of robotics to support kit preparation has received some attention by researchers, but literature is lacking with respect to how collaborative robots – cobots – can support kit preparation activities. The purpose of this paper is to identify the potential of a cobot to support time-efficient batch preparation of kits. To address the purpose, the paper presents a mathematical model for estimation of the cycle time associated with cobot-supported kit preparation. The model is applied in a numerical example with experimental data from laboratory experiments, and cobot-supported kit preparation is compared with manual kit preparation. The findings suggest that cobot-supported kit preparation is beneficial with diverse kits and smaller components quantities per SKU (Stock Keeping Unit) and provides less variability of the outcome, when compared to manual kit preparation. The paper reveals several insights about cobot-supported kit preparation that can be valuable for both academics and practitioners. The model developed can be used by practitioners to assess the potential of cobots to support kit-batch preparation in association with assembly, spare parts, repair and maintenance, or business to business industry.

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