Residual Meso Stresses in Multilevel Crystal Plasticity Models

2014 ◽  
Vol 1040 ◽  
pp. 576-580 ◽  
Author(s):  
Pavel S. Volegov ◽  
Peter V. Trusov ◽  
Dmitry S. Gribov

The problems related to the construction of multi-level mathematical models of inelastic deformation of crystalline materials based on crystal plasticity are considered. The example of the two-level model for description the severe plastic deformation of fcc polycrystals is discussed. The issues relating to the description of hardening and rotations of crystal lattices of the grains are discussed. The focus is on the formation of residual mesostresses in individual grains in the case of polycrystalline stress relief with a representative volume in general.

2014 ◽  
Vol 1013 ◽  
pp. 249-256 ◽  
Author(s):  
Pavel S. Volegov ◽  
Peter V. Trusov

The general structure of the multilevel models of inelastic deformation of materials including the internal structure evolution description was considered in the present paper. It also provides variants to address the key issues of similar type models, which are important for further development of such models. A new approach for constitutive relations coupling between constitutive relations of different scale levels was described. The suggested approach establishes connection of similar characteristics in different scale levels. The proposed coupling method also provides an unambiguous determination of material frame indifferent derivative of the Cauchy stress tensor at the macro scale, which is necessary for the formulation of constitutive relations for large deformations. In order to make it clearer an example of a two-level model of polycrystalline metals is considered; based on the physical sense analysis the hardening laws and lattices rotations of crystallites are suggested.


Author(s):  
Eunyoung Kim ◽  
◽  
Soonbum Kwon ◽  
Meejung Chin ◽  
◽  
...  

2021 ◽  
Vol 11 (5) ◽  
pp. 656
Author(s):  
Pierluigi Zoccolotti ◽  
Paola Angelelli ◽  
Chiara Valeria Marinelli ◽  
Daniele Luigi Romano

Background. Skill learning (e.g., reading, spelling and maths) has been predominantly treated separately in the neuropsychological literature. However, skills (as well as their corresponding deficits), tend to partially overlap. We recently proposed a multi-level model of learning skills (based on the distinction among competence, performance, and acquisition) as a framework to provide a unitary account of these learning skills. In the present study, we examined the performance of an unselected group of third- to fifth-grade children on standard reading, spelling, and maths tasks, and tested the relationships among these skills with a network analysis, i.e., a method particularly suited to analysing relations among different domains. Methods. We administered a battery of reading, spelling, and maths tests to 185 third-, fourth-, and fifth-grade children (103 M, 82 F). Results. The network analysis indicated that the different measures of the same ability (i.e., reading, spelling, and maths) formed separate clusters, in keeping with the idea that they are based on different competences. However, these clusters were also related to each other, so that three nodes were more central in connecting them. In keeping with the multi-level model of learning skills, two of these tests (arithmetic facts subtest and spelling words with ambiguous transcription) relied heavily on the ability to recall specific instances, a factor hypothesised to underlie the co-variation among learning skills. Conclusions. The network analysis indicated both elements of association and of partial independence among learning skills. Interestingly, the study was based on standard clinical instruments, indicating that the multi-level model of learning skills might provide a framework for the clinical analysis of these learning skills.


2021 ◽  
Author(s):  
Artyom A. Tokarev ◽  
Anton Yu. Yants ◽  
Alexey I. Shveykin ◽  
Nikita S. Kondratiev

Sign in / Sign up

Export Citation Format

Share Document