Mechanics of Punching Circular Holes in Materials for Data Handling

1966 ◽  
Vol 88 (4) ◽  
pp. 377-386
Author(s):  
C. A. Queener ◽  
T. C. Smith ◽  
H. E. Gilkey
Keyword(s):  
Theoretical Model ◽  
Total Energy ◽  
Theoretical Approach ◽  
Experimental Results ◽  
Operating Parameters ◽  
Theoretical Treatment ◽  
Data Handling ◽  
Circular Holes ◽  
Punch Displacement ◽  
Good Agreement

A theoretical model is developed in an effort to predict the effect of various design and operating parameters on the mechanics of punching circular holes in relatively ductile, nonmetallic materials which are commonly used in data-handling equipment. Solutions are obtained for the various punch geometries most frequently used. Experimental results for punching force versus punch displacement, maximum punching force, and total energy expended during punching are in good agreement with the theoretical solutions. Although this work is primarily concerned with circular holes, the theoretical approach used is equally applicable to the punching of other hole geometries, such as rectangular holes. The possibility of extending the theoretical treatment to metal punching is also discussed briefly.

Theoretical Model of Plastic Hysteresis in Spherical Contact Under Combined Normal and Tangential Loading

2008 ◽  
Author(s):  
Yuri Kligerman ◽  
Izhak Etsion
Keyword(s):  
Theoretical Model ◽  
Stress State ◽  
Friction Force ◽  
Contact Area ◽  
Contact Condition ◽  
Experimental Results ◽  
Tangential Displacement ◽  
Elastic Plastic ◽  
Plastic Sphere ◽  
Good Agreement

The behavior of an elastic-plastic contact between a deformable sphere and a rigid flat under combined constant normal and reciprocating tangential loading is investigated in the present work. The theoretical model is based on the assumptions of full stick contact condition and two kinds of the sphere material hardening. Hysteretic change of friction force versus tangential displacement during reciprocating tangential loading is investigated along with the study of the change of the contact area and stress state in the elastic-plastic sphere. Good agreement between theoretical and experimental results is obtained.

ELECTRON-PHONON INTERACTION WITHIN THE FRAMEWORK OF THE FLUCTUATING VALENCE OF COPPER ATOMS — A THEORETICAL MODEL FOR HIGH TEMPERATURE SUPERCONDUCTIVITY

1990 ◽  
Vol 04 (05) ◽  
pp. 325-331
Author(s):  
SURESH V. VETTOOR ◽  
V. M. NANDAKUMARAN
Keyword(s):  
High Temperature ◽  
Theoretical Model ◽  
Green's Function ◽  
High Temperature Superconductivity ◽  
Experimental Results ◽  
Function Technique ◽  
Phonon Interaction ◽  
Electron Phonon Interaction ◽  
Good Agreement ◽  
Quasiparticle Excitations

Electron-phonon interaction is considered within the framework of the fluctuating valence of Cu atoms. Anderson's lattice Hamiltonian is suitably modified to take this into account. Using Green's function technique the possible quasiparticle excitations are determined. The quantity 2∆k(0)/k B T c is calculated for T c = 40 K . The calculated values are in good agreement with the experimental results.

Impedance Measurements of Inertance Tubes for Pulse Tube Cryocoolers

2013 ◽  
Vol 718-720 ◽  
pp. 739-744
Author(s):  
S.S. Li ◽  
Y.N. Wu
Keyword(s):  
Theoretical Model ◽  
Turbulent Flow ◽  
Experimental Results ◽  
Operating Parameters ◽  
Pulse Tube ◽  
Impedance Measurements ◽  
General Rules ◽  
Wide Range ◽  
Compressor Piston ◽  
Mass Flows

The impedance of the inertance tubes which include the mass flows, pressure amplitudes and phase shifts between them at the inlet of the inertance tubes were measured by correcting the mass flows at the surface of the compressor piston. The experimental results are compared with the theoretical values based on simplified turbulent-flow thermoacoustic model. The wide range of impedance measurements with different inertance tube geometries and operating parameters enable us to summarize the general rules of their effects on impedance respectively, also the differences between the experiments and calculations can be used to modify the theoretical model.

Novel Polymer Electrets

1999 ◽  
Vol 600 ◽  
Author(s):  
G. M. Sessler ◽  
J. Hillenbrand
Keyword(s):  
Thermal Stability ◽  
Theoretical Model ◽  
Porous Structure ◽  
Piezoelectric Properties ◽  
Experimental Results ◽  
Charge Densities ◽  
New Family ◽  
Thermal Stability Of ◽  
Good Agreement ◽  
Polymer Electrets

AbstractPermanently charged films with a cellular or porous structure represent a new family of polymer electrets. These materials show piezoelectric properties with high transducer constants. The electromechanical response equations of such films are derived for their operation as sensors and as actuators. Experimental results are also presented for cellular polypropylene. In particular, measurements of the direct and inverse transducer constants, the thermal stability of the charge, and Young's modulus are discussed. Assuming reasonable charge distributions and charge densities, the calculated transducer constants are in good agreement with the measured values. Both the theoretical model and the measurements show the reciprocity of the transducer constants.

scholarly journals Theory of efficient shell implosions

1989 ◽  
Vol 7 (2) ◽  
pp. 189-205 ◽  
Author(s):  
Masakatsu Murakami ◽  
Katsunobu Nishihara ◽  
Hideaki Takabe
Keyword(s):  
Theoretical Model ◽  
Neutron Yield ◽  
Mass Density ◽  
Coupling Efficiency ◽  
Experimental Results ◽  
Moderate Intensity ◽  
Ion Temperature ◽  
Hollow Shell ◽  
Theoretical Predictions ◽  
Good Agreement

A theoretical model of spherical ablative implosion is presented. The implosion performances such as the target coupling efficiency are estimated from the aspect ratio and initial mass density of a target shell, provided the laser is fixed at moderate intensity for a given wavelength. The model is applied to the experimental results obtained for both plastic hollow shell targets and DT gas-filled GMB targets by use of the twelve-beam green GEKKO XII laser. In addition to the target coupling efficiency, it is shown for the gas-filled targets that the theoretical predictions of neutron yield, ion temperature, and fuel ρ and ρR are in good agreement with the experimental results. Reduction of neutron yields due to irradiation nonuniformity is also discussed, and 5% of absorption nonuniformity is found to be required for explaining the discrepancies in neutron yield between the experiments and the theory.

Breathing Vibrations of a Horizontal Circular Cylindrical Tank Shell, Partially Filled With Liquid

1995 ◽  
Vol 117 (2) ◽  
pp. 187-191 ◽  
Author(s):  
M. Amabili ◽  
G. Dalpiaz
Keyword(s):  
Dynamic Behavior ◽  
Theoretical Approach ◽  
Cylindrical Shells ◽  
Horizontal Axis ◽  
Experimental Results ◽  
Liquid Level ◽  
Mode Shapes ◽  
Cylindrical Tank ◽  
Qualitative Explanation ◽  
Good Agreement

A theoretical approach to study breathing vibrations of cylindrical shells with horizontal axis, partially filled with liquid, is delineated and the results of some modal tests conducted on an industrially-manufactured tank are presented and discussed. The good agreement between theoretical and experimental results is preliminarily verified in the case of both an empty and completely full shell, in order to confirm that it is possible to apply the theoretical approach to real structures. The modal properties of a partially-filled shell as a function of liquid level are then experimentally studied, the mode shapes are compared using the Modal Assurance Criterium and a qualitative explanation of the dynamic behavior is proposed.

scholarly journals Модель растворения пор на границах зерен при отжиге ультрамелкозернистого алюминиевого сплава

2021 ◽  
Vol 47 (18) ◽  
pp. 40
Author(s):  
М.Ю. Гуткин ◽  
Т.С. Орлова ◽  
Н.В. Скиба
Keyword(s):  
Theoretical Model ◽  
Grain Boundary ◽  
Total Energy ◽  
Grain Boundaries ◽  
Ultrafine Grained ◽  
Model Pore ◽  
Ultrafine Grained Materials ◽  
Good Agreement ◽  
Zr Alloy

A theoretical model which describes the mechanism of pore dissolution at grain boundaries in ultrafine-grained materials during the ageing annealing is suggested. Within the framework of the model, pore dissolution occurs due to the emission of vacancies and the climb of grain-boundary dislocations along the grain boundary towards the pore. It is shown that in this case there is a significant decrease in the total energy of the system. The results of the model are in good agreement with the available experimental observations of pore dissolution during annealing of ultrafine-grained Al-Zr alloy.

scholarly journals Optimization of Thick Film Resistors for Low Drift

1980 ◽  
Vol 7 (1-3) ◽  
pp. 87-91 ◽  
Author(s):  
Gunnar Björklund ◽  
Lars Linde
Keyword(s):  
Theoretical Model ◽  
Thick Film ◽  
Transition Zone ◽  
Experimental Results ◽  
Film Resistor ◽  
Theoretical Predictions ◽  
Thick Film Resistor ◽  
Theoretical Results ◽  
Low Drift ◽  
Good Agreement

In order to minimize drift in a thick film resistor both printing and trimming parameters have to be optimized carefully.With the aid of a linear theoretical model it is shown how the resistance drift in the bulk transition zone and terminals of the resistor can be calculated for both trimmed and untrimmed resistors.The theoretical results are used for optimization of laser trimmed high ohmic resistors. The experimental results are in good agreement with the theoretical predictions and confirm that thick film resistors can be optimized for low drift.

THERMAL FLUCTUATION INFLUENCE ON THE RESISTIVE NOISE IN High-Tc GRANULAR SUPERCONDUCTORS

1999 ◽  
Vol 13 (22n23) ◽  
pp. 783-789
Author(s):  
V. POPESCU ◽  
M. CRISTEA ◽  
A. STEPANESCU
Keyword(s):  
Magnetic Field ◽  
Theoretical Model ◽  
Electrical Resistance ◽  
Thermal Noise ◽  
Thermal Fluctuation ◽  
Experimental Results ◽  
High Tc ◽  
Dc Magnetic Field ◽  
Granular Superconductors ◽  
Good Agreement

Using a recently developed percolative model, we have simulated the contribution of the thermal noise to the total electrical resistance fluctuation in YBCO granular superconductors under a dc magnetic field. The theoretical model is in good agreement with the experimental results.

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.

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