On the geodesic property of strain field patterns in elastoplastic composites

2008 ◽  
Vol 464 (2093) ◽  
pp. 1217-1227 ◽  
Author(s):  
Dominique Jeulin ◽  
Wei Li ◽  
Martin Ostoja-Starzewski
Keyword(s):  
Plastic Flow ◽  
Response Pattern ◽  
Computational Mechanics ◽  
Strain Fields ◽  
Field Patterns ◽  
The Matrix ◽  
Point Field ◽  
Perfect Bonding ◽  
Plastic Hardening ◽  
Sequential Inhibition

Under study is the geodesic (i.e. shortest path) character of strain fields occurring in inelastic response of matrix-inclusion composites. The spatially random morphology of composites is created by generating the inclusions centres through a sequential inhibition process based on a planar Poisson point field preventing any disc overlaps. Both phases (inclusions and matrix) are elastic–plastic hardening with the matrix being more compliant and weaker than the inclusions, and perfect bonding holding everywhere, so that the plastic flow occurs between the inclusions. A quantitative comparison of a response pattern obtained by computational mechanics with that found only by mathematical morphology indicates that (i) the regions of plastic flow are close (or even very close) to geodesics and (ii) a purely geometric (and orders of magnitude more rapid than by computational mechanics) assessment of these regions is possible.

Research of stamping of unequal channel bars. Part 3. Force parameters and shape change of the billet when extruding channels. 1. Kinematic and stress states of the billet

2021 ◽  
pp. 65-71
Author(s):  
A.L. Vorontsov
Keyword(s):  
Plastic Flow ◽  
Complete System ◽  
Shape Change ◽  
Plane Deformation ◽  
System Of Equations ◽  
Flow Rates ◽  
Die Forging ◽  
The Matrix ◽  
Stress States ◽  
Theory Of Plastic Flow

On the basis of the complete system of equations of the theory of plastic flow, the kinematic and stress states of the billet are determined when the channels are extruded under conditions of plane deformation of the misaligned position of the punch and the matrix. Keywords: die forging, extrusion, misaligned position, punch, matrix, plane deformation, plastic flow rates, stresses. [email protected]

Research of stamping of unequal channel bars. Part 3. Force parameters and shape change of the billet when extruding channels. 2. Determination of the extrusion force, maximum pressure on the matrix wall and the heights of the walls, taking into account the elastic deformation jf the matrix

2021 ◽  
pp. 63-69
Author(s):  
A.L. Vorontsov
Keyword(s):  
Plastic Flow ◽  
Elastic Deformation ◽  
Shape Change ◽  
Plane Deformation ◽  
Maximum Pressure ◽  
Extrusion Force ◽  
System Of Equations ◽  
The Matrix ◽  
Theory Of Plastic Flow

On the basis of the system of equations of the theory of plastic flow, the forces, the maximum pressure on the wall of the matrix and the heights of the obtained walls when extruding channels are determined, taking into account the elastic deformation of the matrix. Keywords: die forging, extrusion, misalignment, punch, matrix, plane deformation, stresses. [email protected]

scholarly journals MEASUREMENTS OF STRAIN FIELDS DUE TO NANOSCALE PRECIPITATES USING THE PHASE IMAGE METHOD

2011 ◽  
Vol 20 (3) ◽  
pp. 213
Author(s):  
Patricia Donnadieu ◽  
Kenji Matsuda ◽  
Thierry Epicier ◽  
Joel Douin
Keyword(s):  
Image Analysis ◽  
Strain Field ◽  
Dislocation Motion ◽  
Phase Image ◽  
Image Method ◽  
Hrem Image ◽  
Strain Fields ◽  
The Matrix ◽  
Field Information ◽  
The Impact

Owing the phase image method (Hytch, 1998), strain fields can be derived from HREM images. The method is here applied to the nanoscale precipitates responsible for hardening in Aluminum alloys. Since the method is a very sensitive one, we have examined the impact of several aspects of the image quality (noise, fluctuations, distortion). The strain field information derived from the HREM image analysis is further introduced in a simulation of the dislocation motion in the matrix.

scholarly journals Numerical Modelling of Stress/Strain Field Arising in Diamond-Impregnated Cobalt

2014 ◽  
Vol 59 (2) ◽  
pp. 443-446 ◽  
Author(s):  
J. Borowiecka-Jamrozek ◽  
J. Lachowski
Keyword(s):  
Strain Field ◽  
Diamond Crystal ◽  
Metallic Matrix ◽  
Stress And Strain ◽  
Stress Strain ◽  
Strain Fields ◽  
Matrix Potential ◽  
The Matrix ◽  
Saw Blade ◽  
Diamond Retention

Abstract The paper presents results of computer simulations of the stress/strain field built up in a cobalt matrix diamond impregnated saw blade segment during its fabrication and after loading the protruding diamond with an external force. The main objective of this work was to create better understanding of the factors affecting retention of diamond particles in a metallic matrix of saw blade segments, which are produced by means of the powder metallurgy technology. The effective use of diamond impregnated tools strongly depends on mechanical and tribological properties of the matrix, which has to hold the diamond grits firmly. The diamond retention capability of the matrix is affected in a complex manner by chemical or mechanical interactions between the diamond crystal and the matrix during the segment manufacture. Due to the difference between the thermal expansion coefficients of the diamond and metallic matrix, a complex stress/strain field is generated in the matrix surrounding each diamond crystal. It is assumed that the matrix potential for diamond retention can be associated with the amount of the elastic and plastic deformation energy and the size of the deformation zone occurring in the matrix around diamonds. The stress and strain fields generated in the matrix were calculated using the Abaqus software. It was found that the stress and strain fields generated during segment fabrication change to a large extent as the diamond crystal emerges from the cobalt matrix to reach its working height of protrusion.

Nano- and Microcrystal Investigations of Precipitates, Interfaces and Strain Fields in Ni-Ti-Nb by Various TEM Techniques

2013 ◽  
Vol 738-739 ◽  
pp. 65-71 ◽  
Author(s):  
Dominique Schryvers ◽  
Hui Shi ◽  
Gerardo T. Martinez ◽  
Sandra Van Aert ◽  
Jan Frenzel ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Martensite Plate ◽  
Structural Features ◽  
Present Contribution ◽  
Cast Material ◽  
Strain Fields ◽  
Transformation Temperatures ◽  
The Matrix ◽  
Concentration Changes ◽  
Microscopy Techniques

In the present contribution several advanced electron microscopy techniques are employed in order to describe chemical and structural features of the nano- and microstructure of a Ni45.5Ti45.5Nb9 alloy. A line-up of Nb-rich nano-precipitates is found in the Ni-Ti-rich austenite of as-cast material. Concentration changes of the matrix after annealing are correlated with changes in the transformation temperatures. The formation of rows and plates of larger Nb-rich precipitates and particles is described. The interaction of a twinned martensite plate with a Nb-rich nano-precipitate is discussed and the substitution of Nb atoms on the Ti-sublattice in the matrix is confirmed.

An Interpretation of Slip-Line Field Patterns in Plane Plastic Flow

1963 ◽  
Vol 30 (4) ◽  
pp. 625-627
Author(s):  
M. J. Hillier
Keyword(s):  
Plastic Flow ◽  
Slip Line ◽  
Horizontal Displacement ◽  
Field Pattern ◽  
Line Field ◽  
Slip Line Field ◽  
Contour Maps ◽  
Field Patterns ◽  
Comparison With Experiment ◽  
Plane Plastic

A method of interpretation of slip-line field solutions is proposed. Contour maps showing lines joining points of equal vertical or horizontal displacement velocity are plotted superimposed on the slip-line field pattern for a number of known solutions. The method has the advantage of emphasizing the nature of the theoretical characteristic curves and suggests a method of comparison with experiment.

scholarly journals The Performance Evolution of Match Play Styles in the Spanish Professional Basketball League

2020 ◽  
Vol 10 (20) ◽  
pp. 7056
Author(s):  
Miguel-Ángel Gómez ◽  
Ramón Medina ◽  
Anthony S. Leicht ◽  
Shaoliang Zhang ◽  
Alejandro Vaquera
Keyword(s):  
Mean Squared Error ◽  
Temporal Trends ◽  
Statistical Modelling ◽  
Positive Trend ◽  
Match Play ◽  
Professional Basketball ◽  
The Matrix ◽  
Point Field ◽  
Stable Performance ◽  
Play Styles

The aim of this study is to analyse the performance evolution of all, and the dominant, team’s performances throughout an eight-season period within the Spanish professional basketball league. Match-related statistics were gathered from all regular season matches (n = 2426) played during the period 2009–2010 to 2016–2017. The non-metric multidimensional scaling model was used to examine the team’s profiles across seasons and for the most successful (playoff) teams. The main results showed that: 3-point field goals made (effect size, d = 0.61; 90% confidence interval, CI = 0.23; 1.37) and missed (d = 0.72; 90% CI = 0.35; 1.46), and assists (d = 1.27; 90% CI = 0.82; 1.86) presented a positive trend with an increased number of actions across the seasons; 2-point field goals made (d = 0.21; 90% CI = −1.25; 2.02) and missed (d = 0.27; 90% CI = −0.52; 0.92) were decreased; free throws made and missed, rebounds, fouls, blocks, steals and turnovers showed a relatively stable performance. The matrix solution (stress = 0.22, rmse (root mean squared error) = 7.9 × 104, maximum residual = 5.8 × 103) indicated minimal season-to-season evolution with the ordination plot and convex hulls overlapping. The two most dominant teams exhibited unique match patterns with the most successful team’s pattern, a potential benchmark for others who exhibited more dynamic evolutions (and less success). The current findings identified the different performances of teams within the Spanish professional basketball league over eight seasons with further statistical modelling of match play performances useful to identify temporal trends and support coaches with training and competition preparations.

A Versatile PC-Based Method for the Processing of the Large Matrices

1999 ◽  
Author(s):  
Emil M. Oanta ◽  
Bogdan Nicolescu
Keyword(s):  
Programming Languages ◽  
Computer Aided Design ◽  
High Performance ◽  
Computational Mechanics ◽  
Experimental Mechanics ◽  
Current Application ◽  
Software Applications ◽  
The Matrix ◽  
Aided Design ◽  
High Performance Computers

Abstract In the paper we present a general solution for handling the large matrices. This solution is general because of the wide use of the matrix based approach in problems concerning numerical methods, experimental mechanics, computational mechanics, CFD, computer aided design, economical problems, etc. Some of the major advantages of this solution are: 1. lack of requirements regarding the use of some high-performance computers, the constraints being connected to the size of the hard-disk (at present increasing and being cheaper); 2. Windows operating system may be used but it is not absolutely necessary; 3. it represents an interface between the programming languages; 4. it can easily be used for development of multi-language software applications; 5. applicability in all the domains which use, at the logical level, ‘matrices’ (mathematics, engineering, economics); 6. there are no constraints regarding the use of ‘classic’ solutions techniques; 7. it is easy to implement in software applications already written; 8. data type used as interface may easily be modified in order to be adapted in an optimum way to the current application to be developed. By the use of this solution we solved a series of computer problems and ‘dedicated’ applications in some areas like: Mathematics, Experimental Mechanics, Computational Mechanics, Physics, etc.

PUNCHING CUPS WITH BOTTOM FLANGE BY DIRECT EXTRUSION WITH COUNTER-PUNCH. DETERMINATION OF KINEMATIC AND STRESS STATES IN THE SECOND PERIPHERAL REGION OF PLASTIC DEFORMATION

2020 ◽  
pp. 14-19 ◽  
Author(s):  
A. L. Vorontsov ◽  
I. A. Nikiforov
Keyword(s):  
Plastic Deformation ◽  
Plastic Flow ◽  
Extrusion Process ◽  
Peripheral Region ◽  
Maximum Pressure ◽  
Bottom Flange ◽  
The Matrix ◽  
Stress States ◽  
Theory Of Plastic Flow

Using the theory of plastic flow according to the method of A. L. Vorontsov, the formulas are obtained that are necessary for calculating the stresses and force parameters of the extrusion process with counter-punch of the peripheral region adjacent to the container with the matrix. The maximum pressure acting on the matrix wall and the height of the peripheral region of plastic deformation are determined.

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