Frictional dissipation and stored energy in combined slip and sliding of two spherical grains

The work is actual due to the increased role of electrostatic energy in connection with the beginning of mass production of ionistors used in the power supply system of electric vehicles, and the need for the development of theoretical support. (Research purpose) The research purpose is in increasing the correctness of electrostatic calculations that exclude the possibility of obtaining unreliable results in the form of infinite electrostatic energy. (Materials and methods) Authors have used methods of mathematical modeling and analysis, studied the mathematical model as the equivalent of an object that reflects in mathematical form its most important properties, such as the laws that it obeys, and the relationships inherent in its constituent parts. (Results and discussion) Authors have studied the electrostatic field created by a system of two charges of the same name or different names. The article presents calculations for charges located in bodies that have the shape of balls. It was found that the results could be generalized to any form of charged objects. They gave three definitions: first, the total stored energy is the energy of the system or object, equal to the maximum work that the system or object can do if it is given such an opportunity. Second, the conditional realized stored energy is a part of the total stored energy of the system or object, equal to the work that the system or object can produce, limited by a condition that excludes the possibility of the system or object performing the maximum work that the system or object can hypothetically perform. The third is a conditional impossible reserved energy as a part of a complete stored energy system or an object that is equal to the work system or object can do and limited by the condition, which excludes the possibility of making a system or object maximum work that target system or object could hypothetically do. Five theorems were proved. (Conclusions) It was found that the main drawback of the actual potential energy formula is an infinitely large increase in energy at radius tending to 0. The obtained formulas for stored electrostatic energy are devoid of this drawback.

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Dynamics of the Ice-Crushing Process

Journal of Glaciology ◽

10.1017/s0022143000007085 ◽

1988 ◽

Vol 34 (118) ◽

pp. 318-326 ◽

Cited By ~ 36

Author(s):

Ian J. Jordaan ◽

Garry W. Timco

Keyword(s):

Ice Sheet ◽

Load Cycle ◽

Stored Energy ◽

Indentation Process ◽

Ice Particles ◽

Mode Of Failure ◽

Indentation Tests ◽

Energy Exchanges ◽

The Mean ◽

Crushed Ice

Abstract During fast indentation tests on ice sheets at constant rates, crushing is commonly observed at appropriate combinations of speed and aspect ratio. An analysis is made of this mode of failure, using as a basis a recently conducted test on an ice sheet under controlled conditions. The variation of load with time is given special attention, and cyclic variation of load is associated with periodic crushing (pulverization) events, followed by clearing of the crushed ice particles. An analysis of the clearing process is summarized in the paper, treating the crushed ice as a viscous material. A detailed analysis of the energy exchanges during the indentation process is given. Elastic variations of stored energy in the indenter and in the ice sheet are calculated; these are relatively minor. The dissipation of energy during a typical load cycle (3 mm movement during 0.05 s) is about 8 J. The energy required to create surfaces of the crushed ice particles is small (0.006 J), as is the work of crushing based on mechanical testing (0.09 J). It is concluded that the process of viscous extrusion of crushed ice is the main seat of energy dissipation, basically as a frictional process. A relationship for the mean thickness of the crushed ice layer is developed, based on energy-balance considerations.

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A Novel Damage Model for Strata Layers and Coal Mass

Energies ◽

10.3390/en13081928 ◽

2020 ◽

Vol 13 (8) ◽

pp. 1928 ◽

Cited By ~ 2

Author(s):

Faham Tahmasebinia ◽

Chengguo Zhang ◽

Ismet Canbulat ◽

Samad Sepasgozar ◽

Serkan Saydam

Keyword(s):

Constitutive Model ◽

Strain Energy ◽

Damage Model ◽

Rock Joint ◽

Coal Mass ◽

Stored Energy ◽

Rock Interaction ◽

Geological Factors ◽

Coal Rock ◽

Joint Quality

Coal burst occurrences are affected by a range of mining and geological factors. Excessive slipping between the strata layers may release a considerable amount of strain energy, which can be destructive. A competent strata is also more vulnerable to riveting a large amount of strain energy. If the stored energy in the rigid roof reaches a certain level, it will be released suddenly which can create a serious dynamic reaction leading to coal burst incidents. In this paper, a new damage model based on the modified thermomechanical continuum constitutive model in coal mass and the contact layers between the rock and coal mass is proposed. The original continuum constitutive model was initially developed for the cemented granular materials. The application of the modified continuum constitutive model is the key aspect to understand the momentum energy between the coal–rock interactions. The transformed energy between the coal mass and different strata layers will be analytically demonstrated as a function of the rock/joint quality interaction conditions. The failure and post failure in the coal mass and coal–rock joint interaction will be classified by the coal mass crushing, coal–rock interaction damage and fragment reorganisation. The outcomes of this paper will help to forecast the possibility of the coal burst occurrence based on the interaction between the coal mass and the strata layers in a coal mine.

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Polyconvex hyperelastic modeling of rubberlike materials

Journal of the Brazilian Society of Mechanical Sciences and Engineering ◽

10.1007/s40430-021-03062-w ◽

2021 ◽

Vol 43 (7) ◽

Author(s):

Cyprian Suchocki ◽

Stanisław Jemioło

Keyword(s):

Experimental Data ◽

Power Law ◽

Curve Fitting ◽

Constitutive Relations ◽

Data Sets ◽

Power Law Model ◽

Stored Energy ◽

Data Approximation ◽

Exponential Power ◽

Hyperelastic Models

AbstractIn this work a number of selected, isotropic, invariant-based hyperelastic models are analyzed. The considered constitutive relations of hyperelasticity include the model by Gent (G) and its extension, the so-called generalized Gent model (GG), the exponential-power law model (Exp-PL) and the power law model (PL). The material parameters of the models under study have been identified for eight different experimental data sets. As it has been demonstrated, the much celebrated Gent’s model does not always allow to obtain an acceptable quality of the experimental data approximation. Furthermore, it is observed that the best curve fitting quality is usually achieved when the experimentally derived conditions that were proposed by Rivlin and Saunders are fulfilled. However, it is shown that the conditions by Rivlin and Saunders are in a contradiction with the mathematical requirements of stored energy polyconvexity. A polyconvex stored energy function is assumed in order to ensure the existence of solutions to a properly defined boundary value problem and to avoid non-physical material response. It is found that in the case of the analyzed hyperelastic models the application of polyconvexity conditions leads to only a slight decrease in the curve fitting quality. When the energy polyconvexity is assumed, the best experimental data approximation is usually obtained for the PL model. Among the non-polyconvex hyperelastic models, the best curve fitting results are most frequently achieved for the GG model. However, it is shown that both the G and the GG models are problematic due to the presence of the locking effect.

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Stored Energy Welding Technology of Ultra-Thin Sheet Stainless Steel

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.749.27 ◽

2013 ◽

Vol 749 ◽

pp. 27-30

Author(s):

Hao Bin Zhou ◽

Ju Lian Ma ◽

Xiang Qian Xu

Keyword(s):

Stainless Steel ◽

Spot Welding ◽

Joint Strength ◽

Thin Sheet ◽

Welding Parameter ◽

Welding Parameters ◽

Dynamic Resistance ◽

Stored Energy ◽

Welding Technology ◽

The Hard Problem

Considering the characteristics of the multilayered ultra-thin sheet stainless steel, by chosen the proper equipments and stored energy welding technology, the optimizing welding parameters are got from the condenser discharge spot welding experiments. The energy stored in the capacitor group is controlled by the energy required during welding and the discharge current is controlled by the size of dynamic resistance in resistance spot welding. So those control ways can better solve the hard problem of choosing welding parameter. The joint strength of ultra-thin sheet stainless steel is ensured by the reasonable quality assessment methods. The processed spot-welded joints are of good quality and appearance.

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An investigation of stored energy in uniaxial and biaxial directional rolling on mechanical properties and microstructure of pure copper

Mechanics Based Design of Structures and Machines ◽

10.1080/15397734.2021.1909484 ◽

2021 ◽

pp. 1-13

Author(s):

S. P. Sundar Singh Sivam ◽

R. Rajendran ◽

N. Harshavardhana

Keyword(s):

Mechanical Properties ◽

Pure Copper ◽

Stored Energy

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Limitations on stored energy densities in systems of separated ionicspecies

Journal of Propulsion and Power ◽

10.2514/3.23438 ◽

1992 ◽

Vol 8 (1) ◽

pp. 30-36 ◽

Cited By ~ 5

Author(s):

Mario E. Fajardo

Keyword(s):

Stored Energy

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An Assessment of Bulk and Local Stored Energy Measurements in Ultrafine Grained Interstitial Free Steel

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.89-91.244 ◽

2010 ◽

Vol 89-91 ◽

pp. 244-249 ◽

Cited By ~ 1

Author(s):

Sujoy S. Hazra ◽

Azdiar A. Gazder ◽

Elena V. Pereloma

Keyword(s):

Profile Analysis ◽

Energy Estimates ◽

Internal Stresses ◽

Line Profile Analysis ◽

Interstitial Free ◽

Stored Energy ◽

Scanning Calorimetry ◽

Angular Pressing ◽

Ultrafine Grained ◽

Interstitial Free Steel

The evolution of stored energy and associated thermal behaviour was investigated for an ultrafine grained Ti-IF steel severely deformed by Equal Channel Angular Pressing (ECAP) followed by cold rolling at ambient and liquid nitrogen temperatures. Bulk stored energy measurements by Differential Scanning Calorimetry (DSC) returned 350-600 whereas local stored energy estimates from microhardness, Electron Back-Scattering Diffraction (EBSD) and X-ray line profile analysis resulted in 5-140 . Higher bulk stored energy values correspond to the enthalpy release from all sources of strain in the material volume as well as Ti precipitation during annealing while the lower local stored energy range alludes only to dislocation content or internal stresses. An apparent activation energy of 500-550 suggests sluggish recrystallisation due to excess of Ti in solid solution.

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