METHODOLOGICAL PROBLEMS IN EXPERIMENTAL STUDIES AND VERIFICATION OF THE GOVERNING EQUATIONS OF THE THEORY OF ELASTICITY FOR AN ISOTROPIC BODY WITH DIFFERENT MODULI IN TENSION AND COMPRESSION

2020 ◽  
Vol 61 (6) ◽  
pp. 979-985
Author(s):  
A. A. Adamov
Keyword(s):  
Experimental Studies ◽  
Isotropic Body ◽  
Theory Of Elasticity ◽  
Governing Equations ◽  
Tension And Compression ◽  
Methodological Problems

Methodology of studying the mechanical properties of composite materials (reinforced concrete)

2018 ◽  
Vol 84 (12) ◽  
pp. 61-67
Author(s):  
V. A. Eryshev
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Experimental Studies ◽  
Analytical Relationship ◽  
Hardened Concrete ◽  
Deformation Model ◽  
Joint Work ◽  
Concrete Shrinkage ◽  
Axial Tension ◽  
Tension And Compression

The mechanical properties of a complex composite material formed by steel and hardened concrete, are studied. A technique of operative quality control of new credible concrete and reinforcement, both in laboratory and field conditions is developed for determination of the strength and strain characteristics of materials, as well as cohesion forces determining their joint operation under load. The design of the mobile unit is presented. The unit provides a possibility of changing the direction of loading and testing the reinforced element of the given shape both for tension and compression. Moreover, the nomenclature of testing equipment and the number of molds for manufacturing concrete samples substantially decrease. Using the values of forcing resulting in concrete cracking when the joint work of concrete and reinforcement is disrupted the values of the inherent stresses and strains attributed to the concrete shrinkage are determined. An analytical relationship between the forces and deformations of the reinforced concrete sample with central reinforcement is derived for axial tension and compression, with allowance for strains and stresses in the reinforcement and concrete resulted from concrete shrinkage. The results of experimental studies are presented, including tension diagrams and diagrams of developing axial deformations with an increase in the load under the central loading of the reinforced elements. A methodology of accounting for stresses and deformations resulted from concrete shrinkage is developed. The applicability of the derived analytical relationships between stresses and deformations on the material diagrams to calculations of the reinforced concrete structures in the framework of the deformation model is estimated.

The History and Status of the Journal of Sport Psychology: 1979-1985

1986 ◽  
Vol 8 (3) ◽  
pp. 149-163 ◽  
Author(s):  
Daniel M. Landers ◽  
Stephen H. Boutcher ◽  
Min Q. Wang
Keyword(s):  
Sport Psychology ◽  
Statistical Tests ◽  
Experimental Studies ◽  
The Past ◽  
Subject Selection ◽  
Research Areas ◽  
Time Period ◽  
Methodological Problems ◽  
The Common ◽  
Single Set

In the past 7 years JSP has evolved to become a respected sport psychology journal. The journal has been uncompromising in the strong research posture it has taken. It is currently the only journal entirely devoted to sport psychology that uses a single set of criteria for evaluating the scientific merit of submitted manuscripts. Over this time period the submitted manuscripts have shown an increase in the number of female principal authors as well as authors being affiliated with departments other than physical education. Survey studies were the most common submittals, but lately there has been a greater emphasis in field experimental studies. Some potential problem areas are noted in subject selection and choice of statistical tests. An examination of research areas revealed that in recent years "motivation" was the most frequently submitted topic. It appeared that other research areas varied in terms of their publishability. The common methodological problems associated with rejection of these types of manuscripts are discussed.

A Refined Theory for Laminated Anisotropic, Cylindrical Shells

1974 ◽  
Vol 41 (2) ◽  
pp. 471-476 ◽  
Author(s):  
J. M. Whitney ◽  
C.-T. Sun
Keyword(s):  
Shear Deformation ◽  
Shell Theory ◽  
Theory Of Elasticity ◽  
Small Radius ◽  
Refined Theory ◽  
Normal Strain ◽  
Governing Equations ◽  
Transverse Normal Strain ◽  
Anisotropic Cylindrical Shell ◽  
Good Agreement

A set of governing equations and boundary conditions are derived which describe the static deformation of a laminated anisotropic cylindrical shell. The theory includes both transverse shear deformation and transverse normal strain, as well as expansional strains. The validity of the theory is assessed by comparing solutions obtained from the shell theory to results obtained from exact theory of elasticity. Reasonably good agreement is observed and both shear deformation and transverse normal strain are shown to be of importance for shells having a relatively small radius-to-thickness ratio.

scholarly journals The Work-family Field: Gaps and Missing Links as Opportunities for Future Research

Innovar ◽  
2017 ◽  
Vol 27 (66) ◽  
pp. 57-74 ◽  
Author(s):  
Katherina Kuschel
Keyword(s):  
Selection Bias ◽  
Effect Size ◽  
Meta Analysis ◽  
Experimental Studies ◽  
Future Research ◽  
Positive Side ◽  
Self Selection ◽  
Conference Presentations ◽  
Methodological Problems ◽  
Work Family

This review presents a synthesis and a critique of the development of the existing workfamily (WF) literature during the last decade in order to highlight gaps and limitations in current research. The study revises 83 peer-reviewed articles, book chapters and conference presentations (2004-2014) related to WF in economics, management and psychology disciplines, and classifies the current research into three broad themes for future research paths: i) definitions and theories; ii) background and outcomes of wf conflict, balance and enrichment; and iii) methodological gaps. Advances have been made this decade on meta-analysis and the understanding of the positive side of WF interface. Future research opportunities in this field will include a deeper understanding of how to effectively cope with WF conflict, how to achieve WF enrichment, the use of different methods (qualitative, longitudinal and experimental studies) on samples of new occupations, and how researchers could address methodological problems (causality, endogeneity, simultaneity, effect size, and self-selection bias) to better handle the complexity of WF issues.

Bending analysis of sandwich plates with composite face sheets and compliance functionally graded syntactic foam core

2016 ◽  
Vol 230 (20) ◽  
pp. 3606-3630 ◽  
Author(s):  
Mohammad Javad Lashkari ◽  
Omid Rahmani
Keyword(s):  
Plate Theory ◽  
Theory Of Elasticity ◽  
Functionally Graded ◽  
Shear Stresses ◽  
Rectangular Plates ◽  
Governing Equations ◽  
Positive Role ◽  
Virtual Displacement ◽  
The Core ◽  
Composite Face

In this paper, the problem of a rectangular plate with functionally graded soft core and composite face sheets is considered using high order sandwich plate theory. This theory applies no assumptions on the displacement and stress fields in the core. Face sheets were treated using classical theory and core was exposed to the theory of elasticity. Governing equations and boundary conditions are derived using principle of virtual displacement and the governing equations are based on eight primary variables including six displacements and two shear stresses. This solution is able to present localized displacements and stresses in places where concentrated loads are exerted to the structure since the displacements in the core can take a nonlinear form which could not be seen in the previous theories such as classical and higher order shear theories. This theory is suitable for rectangular plates under all types of loadings distributed or concentrated which can be different on upper and lower face sheets at the same point. The results were compared with the published literature using theory of elasticity and showed good agreement confirming the accuracy of the present theory. Subsequently, the solution for the core with functionally graded material is presented and effectively indicates positive role of functionally graded core.

Axial Loading of Annular Bonded Rubber Blocks

2003 ◽  
Vol 76 (5) ◽  
pp. 1194-1211 ◽  
Author(s):  
J. M. Horton ◽  
G. E. Tupholme ◽  
M. J. C. Gover
Keyword(s):  
Experimental Data ◽  
Stress Distribution ◽  
Closed Form ◽  
Cross Section ◽  
Classical Theory ◽  
Cross Sections ◽  
Axial Loading ◽  
Theory Of Elasticity ◽  
Governing Equations ◽  
Annular Cross Section

Abstract Closed-form expressions are derived using a superposition approach for the axial deflection and stress distribution of axially loaded rubber blocks of annular cross-section, whose ends are bonded to rigid plates. These satisfy exactly the governing equations and conditions based upon the classical theory of elasticity. Readily calculable relationships are derived for the corresponding apparent Young's modulus, Ea, and the modified modulus, Ea′, and their numerical values are compared with the available experimental data. Elementary expressions for evaluating Ea and Ea′ approximately are deduced from these, in forms which are closely analogous to those given previously for blocks of circular and long, thin rectangular cross-sections. The profiles of the deformed lateral surfaces of the block are discussed and it is confirmed that the assumption of parabolic lateral profiles is not valid generally.

scholarly journals Vibration, synchronization and localization of three-bladed rotor: theoretical and experimental studies

2021 ◽  
Author(s):  
Z. Szmit
Keyword(s):  
Experimental Studies ◽  
Experimental Tests ◽  
Experimental Methods ◽  
Forced Response ◽  
Governing Equations ◽  
Complex Dynamic ◽  
Flexible Beams ◽  
Free And Forced Vibrations ◽  
Bladed Rotor ◽  
Rotating Structure

AbstractNumerical and experimental methods in free and forced vibrations of the rotating structure consisting of the rigid hub and three flexible beams are considered. Firstly, the system of four mutually coupled dimensionless differential governing equations is presented and then forced response of the system as well as synchronization phenomenon are investigated. Next, the finite elements method is used to design the rotating structure and analyse complex dynamic response. During the numerical calculations symmetric, as well as de-tuned rotor are analyzed. Finally, results obtained from ordinary differential equations and numerical simulations are compared with experimental tests.

scholarly journals A modification of the CABARET scheme for numerical simulation of multicomponent gaseous flows in two-dimensional domains

2015 ◽  
pp. 436-445
Author(s):  
А.В. Данилин ◽  
А.В. Соловьев ◽  
А.М. Зайцев
Keyword(s):  
Numerical Simulation ◽  
Initial Conditions ◽  
Experimental Studies ◽  
Two Dimensional ◽  
Governing Equations ◽  
Cabaret Scheme ◽  
Gaseous Flows ◽  
Multicomponent Gas ◽  
Good Agreement ◽  
Made In

Предложен явный численный алгоритм для расчета течений смесей идеальных газов в двумерных областях. Приведены физическая модель и уравнения движения смеси в консервативной и характеристической формах. Дискретизация уравнений движения произведена по методике Кабаре. Алгоритм испытан на задачах о прохождении ударной волны в воздухе через неоднородности из легкого и тяжелого газов, начальные условия для которых адаптированы из рассмотренных другими авторами натурных и численных экспериментов. Показано хорошее совпадение расчетов по предложенному алгоритму с результатами этих экспериментов. An explicit numerical algorithm for calculation of two-dimensional motion of multicomponent gas mixtures is proposed. A physical model as well as conservative and characteristic forms of governing equations are given. The discretization of the governing equations is made in accordance with the CABARET (Compact Accurately Boundary Adjusting-REsolution Technique) approach. The proposed algorithm is tested on problems of air shock waves passing through dense and dilute volume inhomogeneities with initial conditions adopted from numerical and experimental studies of other authors. A good agreement between the results of these studies and those obtained by the CABARET approach is shown.

scholarly journals Two stage ejector as a pre-stage of the water ring vacuum pump

2019 ◽  
Vol 20 (7) ◽  
pp. 703
Author(s):  
Róbert Olšiak ◽  
Marek Mlkvik ◽  
František Ridzoň ◽  
Pavol Slovák
Keyword(s):  
Experimental Studies ◽  
Vacuum Pump ◽  
3D Printer ◽  
Cfd Analysis ◽  
Suction Pressure ◽  
Governing Equations ◽  
Flow Through ◽  
Definition Of ◽  
Water Ring ◽  
Liquid Ring

A supersonic gas ejector in conjunction with a liquid ring vacuum pump is used for creating and maintaining a vacuum in a chamber for technological purposes. In this paper, the authors submit an overview of the problematics of suction pressure reduction with a supersonic gas ejector used as a pre-stage of a liquid ring vacuum pump. This system has also the function of a cavitation protection due to the higher pressure present at the suction throat of the vacuum pump. A part of this paper is devoted to the governing equations used at the definition of the flow through an ejector. The CFD analysis of the problem was implemented with the package Fluent in 2 dimensions using the axisymmetric approach. The parts of the physical model were printed on a STRATASYS 3D printer, or were cast from technical resin. The experimental studies are then carried out in our own laboratory for validation purposes.

Sign in / Sign up

Export Citation Format

Share Document