scholarly journals Structural Monitoring of Underground Structures in Multi-Layer Media by Dynamic Methods

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5241 ◽  
Author(s):  
Alexandr Lyapin ◽  
Alexey Beskopylny ◽  
Besarion Meskhi
Keyword(s):  
Half Space ◽  
Dynamic Load ◽  
Fourier Transforms ◽  
Sensor System ◽  
Structural Monitoring ◽  
Dynamic Features ◽  
Surface Source ◽  
Stress Strain ◽  
Dynamic Surface ◽  
Actual Problem

The actual problem of structural monitoring and modeling of dynamic response from buried building is considered in the framework of arbitrary dynamic load. The results can be used for designing underground transport constructions, crossings, buried reservoirs and foundations. In existing methods, the system of sensors that register the response to a dynamic action does not allow for effective interpretation of the signal without understanding the dynamic features and resonance phenomena. The analytical and numerical solution of the problem of the dynamics of a buried object in a layered medium is considered. A multilayer half-space is a set of rigidly interconnected layers characterized by elastic properties. At a distance, an arbitrary dynamic load acts on the half-space, which causes oscillations in the embedded structure, and the sensor system registers the response. The problem of assessing the dynamic stress-strain state (DSSS) is solved using Fourier transforms with the principle of limiting absorption. As an example, the behavior of an embedded massive structure of an underground pedestrian crossing under the influence of a dynamic surface source on a multilayer medium is considered, as well as instrumental support of the sensor system. The solution in the form of stress, strain and displacement fields is obtained and compared with the experimental data. The frequency-dependent characteristics of the system are determined and the possibility of determining the DSSS by a shock pulse is shown.

PERSONALITIES OF PSYCHOLOGY STUDENTS DYNAMIC FEATURES OF SELF-EFFICIENCY

2020 ◽  
Vol 65 (4) ◽  
pp. 170-177
Author(s):  
N. A. Kudusheva ◽  
◽  
I. K. Amanova ◽  
Keyword(s):  
Self Efficacy ◽  
Psychology Students ◽  
Dynamic Features ◽  
Actual Problem ◽  
Theoretical Approaches ◽  
The University ◽  
Multicomponent Nature ◽  
Independent Work ◽  
The Relationship ◽  
Linear Nature

The article deals with the problem of the dynamics of personal self-efficacy of psychology students during their studies at the University. Theoretical approaches to understanding the term "self-efficacy" and its relation to related concepts related to psychological confidence and personal potential are analyzed.The actual problem of personal self-efficacy of psychology students is discussed.The results of an empirical study of the dynamic characteristics of self-efficacy of a sample of 80 students are presented, and statistical indicators of subject self-efficacy and development of self-efficacy in communication, their relationship with the motivation for choosing a profession and the level of self-attitude are determined.Dynamism, integrity and multicomponent nature of self-efficacy; non-linear nature of its development at different stages of training; the relationship between the level of self-efficacy development and the experience of independent work.

The Effect of a Thin Layer Surface Inhomogeneity on Dynamic Surface Response

1978 ◽  
Vol 45 (1) ◽  
pp. 95-99 ◽  
Author(s):  
L. M. Brock
Keyword(s):  
Thin Layer ◽  
Half Space ◽  
Critical Parameter ◽  
Rigid Bodies ◽  
Layer Surface ◽  
Noticeable Effect ◽  
Dynamic Surface ◽  
Surface Inhomogeneity ◽  
Interface Waves ◽  
Surface Response

A thin layer surface inhomogeneity consisting of small, evenly distributed rigid bodies is perfectly bonded to an elastic half space. Constant normal and shear line loads are applied to the layer and the dynamic surface response is calculated by Laplace transform techniques. The product of the layer thickness and the rigid body/half-space mass densities proves to be a critical parameter in determining the response. It is found that the layer has a noticeable effect on the half-space surface response in relation to the free-surface behavior. In particular, while no standard surface-interface waves exist, evidence for small values of the critical parameter indicates the presence of pseudo-Rayleigh waves similar to those found in fluid-solid interface analyses.

NUMERICAL INVESTIGATION OF THERMOMECHANICAL PROCESSES UNDER SHORT-PULSED LASER IRRADIATION OF A HALF-SPACE

2021 ◽  
Vol 6 ◽  
pp. 55-65
Author(s):  
Kamila Storchak ◽  
◽  
Nina Yakovenko ◽  
Olga Polonevych ◽  
Irina Sribna ◽  
...  
Keyword(s):  
Residual Stress ◽  
Laser Irradiation ◽  
Half Space ◽  
Strain State ◽  
Thermal Stresses ◽  
Equations Of Motion ◽  
Thermomechanical Loading ◽  
Stress Strain ◽  
Stress Strain State ◽  
Residual Strains

The laser irradiation of metallic surfaces by intense heat sources is used for the generation of short probing pulses, which propagate into thin specimens and enable one to estimate their structure and mechanical properties within the framework of the classical acoustic approach. High thermal stresses and residual strains occur during the short-term irradiation of the surface of a construction by an energy source of high density. In the present work, we solve the axially symmetric problem of a half-space under thermomechanical loading. We take into account the influence of volume and inelastic characteristics of separate phases on the residual stress-strain state of the half-space. The statement of the problem includes: Cauchy relations, equations of motion, heat conduction equation, initial conditions, thermal and mechanical boundary conditions. The thermomechanical behavior of an isotropic material is described by the Bodner-Partom unified model of flow. The problem is solved with using the finite element technique. The numerical realization of our problem is performed with the help of step-by-step time integration. The equations of motion are integrated by the Newmark method. The residual stress-strain state is described using the method of numerical solution of the axisymmetric dynamic problem for a half-space under thermomechanical loading and the flow model. We established that microstructural transformations, which are taken into account due to the thermophase volume strain and dependence of inelastic characteristics of the material on the phase composition, significantly reduce residual inelastic strain and promote the appearance of compressive stresses. The three-zone region of residual stresses field formation is obtained.

scholarly journals Dynamic Load Balancing of Samr Applications on Distributed Systems

2002 ◽  
Vol 10 (4) ◽  
pp. 319-328 ◽  
Author(s):  
Zhiling Lan ◽  
Valerie E. Taylor ◽  
Greg Bryan
Keyword(s):  
Distributed Systems ◽  
Load Balancing ◽  
Dynamic Load ◽  
Adaptive Mesh Refinement ◽  
Heuristic Method ◽  
Adaptive Mesh ◽  
Dynamic Load Balancing ◽  
Dynamic Features ◽  
Structured Adaptive Mesh Refinement ◽  
Two Phases

Dynamic load balancing(DLB) for parallel systems has been studied extensively; however, DLB for distributed systems is relatively new. To efficiently utilize computing resources provided by distributed systems, an underlying DLB scheme must address both heterogeneous and dynamic features of distributed systems. In this paper, we propose a DLB scheme for Structured Adaptive Mesh Refinement(SAMR) applications on distributed systems. While the proposed scheme can take into consideration (1) the heterogeneity of processors and (2) the heterogeneity and dynamic load of the networks, the focus of this paper is on the latter. The load-balancing processes are divided into two phases: global load balancing and local load balancing. We also provide a heuristic method to evaluate the computational gain and redistribution cost for global redistribution. Experiments show that by using our distributed DLB scheme, the execution time can be reduced by 9%- to using parallel DLB scheme which does not consider the heterogeneous and dynamic features of distributed systems.

scholarly journals A note on dynamic surface displacements in an elastic half-space

1973 ◽  
Vol 17 (1-2) ◽  
pp. 145-152 ◽  
Author(s):  
O. F. Afandi ◽  
R. A. Scott
Keyword(s):  
Half Space ◽  
Elastic Half Space ◽  
Dynamic Surface ◽  
Surface Displacements
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