scholarly journals Analytical Method for Determination of Internal Forces of Mechanisms and Manipulators

Robotics ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 53 ◽  
Author(s):  
Muratulla Utenov ◽  
Tarek Sobh ◽  
Zhumadil Baigunchekov ◽  
Saltanat Zhilkibayeva ◽  
Sarosh Patel
Keyword(s):  
Cross Sections ◽  
Discrete Model ◽  
Discrete Models ◽  
Dynamic Loads ◽  
Dynamic Equations ◽  
Analytical Determination ◽  
Kinematic Characteristics ◽  
Internal Forces ◽  
Rigid Joints

This paper presents a theory for the analytical determination of internal forces in the links of planar linkage mechanisms and manipulators with statically determinate structures, considering the distributed dynamic loads. Linkage mechanisms and manipulators were divided into elements and joints. Discrete models were created for both the elements and the entire mechanism. The dynamic equations of equilibrium for the discrete model of the elements and the hinged and rigid joints, under the action of longitudinal and transverse distributed dynamic trapezoidal loads, were derived. In the dynamic equations of the equilibrium of the discrete model of the elements and joints, the connections between the components of the force vector in the calculated cross-sections and the geometric, physical, and kinematic characteristics of the element were established for its plane-parallel motion. According to the developed technique, programs were created in the Maple system, and animations of the motion of the mechanisms were produced. The links were constructed with the intensity of transverse- and longitudinal-distributed dynamic loads, bending moments, and shearing and normal forces, depending on the kinematic characteristics of the links.

Analytical Determination of Generation-Recombination Rate In Amorphous Silicon

1986 ◽  
Vol 70 ◽  
Author(s):  
Jože Furlan ◽  
Slavko Amon
Keyword(s):  
Analytical Solution ◽  
Amorphous Silicon ◽  
Cross Sections ◽  
Recombination Rate ◽  
Exponential Model ◽  
Localized States ◽  
Analytical Determination ◽  
Capture Cross ◽  
Capture Cross Sections

ABSTRACTA general expression for generation-recombination rate in a-Si based on classical SRH theory including different electron and hole capture cross-sections for donor-like and acceptor-like centers inside the mobility gap is derived. Applying appropriate approximations and two-exponential model for localized states distribution two methods of analytical solution are presented and discussed.

scholarly journals The concept of a prefabricated structure for protection of critical infrastructure facilities

2018 ◽  
Vol 67 (2) ◽  
pp. 133-144
Author(s):  
Kamil Sobczyk ◽  
Ryszard Chmielewski ◽  
Krzysztof Duda
Keyword(s):  
Reinforced Concrete ◽  
Computational Analysis ◽  
Critical Infrastructure ◽  
High Mobility ◽  
Dynamic Loads ◽  
Protective Structure ◽  
Internal Forces ◽  
Prefabricated Structure ◽  
Building Engineering

The paper presents the concept of a protective structure in the form of a prefabricated reinforced concrete protective dome intended for protection of a single critical infrastructure facility [1]. Unlike non-movable cast-in-place reinforced concrete structures, the protective structure can be assembled and disassembled repeatedly with the use of dedicated joining sockets. To provide the concept with a high mobility, the dimensions of single modules of the prefabricated reinforced concrete protective dome meet the transport limits dictated by the horizontal and vertical clearance of roads. A numerical computational analysis facilitated a determination of the distribution of internal forces in the protective stricture and dimensioning of the required reinforcement system [3]. The computations included standardized cases of steady and dynamic loads, and combinations thereof, complete with parameters of dynamic loads from an explosion impulse. Keywords: building engineering, protective structure, prefabricated dome

ANALYTICAL DETERMINATION OF THE PERMEABILITY FOR SLOW FLOW PAST PERIODIC ARRAYS OF CYLINDERS WITH DIFFERENT CROSS SECTIONS

2012 ◽  
Vol 15 (11) ◽  
pp. 1009-1018 ◽  
Author(s):  
A. Cihat Baytas ◽  
D. Erdem ◽  
H. Acar ◽  
O. Cetiner ◽  
H. Basci
Keyword(s):  
Cross Sections ◽  
Analytical Determination ◽  
Slow Flow ◽  
Periodic Arrays ◽  
Flow Past

scholarly journals Influence of breakages of cable groups on strength ofrubber-cable tractive-transporting element

2021 ◽  
Vol 64 ◽  
pp. 166-174
Author(s):  
I Belmas ◽  
D Kolosov ◽  
O Dolgov ◽  
H Tantsura ◽  
S Onyshchenko
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Strain State ◽  
Elastic Shell ◽  
Practical Significance ◽  
Analytical Determination ◽  
Shear Stresses ◽  
Stress Strain ◽  
Stress Strain State

Purpose. Development and justification of a method of analytical determination of a stress-strain state of a flat rubber-cable tractive-transporting element with breakages of continuity of cable groups in different cross-sections. Methodology of research is in development of a mathematical model of interaction of tractive-transporting element parts considering breakages of groups of random cables, construction of analytical solutions for determining dependencies of force distribution between cables and shear stresses in an elastic shell of a tractive-transporting element with random locations of breakages of cable groups in different cross-sections. Findings. A model of a flat rubber-cable tractive-transporting element with random locations of breakages of cable groups in different cross-sections is developed. Expressions that allow determining a stress-strain state of a flat rubber-cable tractive-transporting element of a hoisting and transporting machine with random locations of breakages of cable groups in different cross-sections are obtained analytically in a closed form. Strength conditions are formulated. Scientific novelty is in establishment of dependencies of interaction of disturbance fields of a stress-strain state of a rubber-cable tractive-transporting element with breakages of continuity of random cable groups in different cross-sections. It is established that disturbance fields caused by breakages of adjacent cables overlap when the breakages are located in one cross-section and there are less than three whole cables located between the broken cables. Disturbance fields also overlap when the same cable or the adjacent cable is broken in both cross-sections and the distance between cross-sections of breakage does not exceed the value, which depends on the design of a flat rubber-cable tractive-transporting element and mechanical properties of its components. Practical significance. The obtained algorithms and strength conditions allow determining a stress-strain state and preventing the breakage of the entire flat rubber-cable tractive-transporting element with breakages of cable groups in different cross-sections. These cross-sections can be: cross-section of the edge of a butt joint, where cables have breakages of continuity; cross-section, which includes the edge of an area of partial restoration of a tractive ability of the element, lost due to breakage of a cable; cross-section of cable or cable group breakage during operation. A possibility of establishing a stress-strain state and the strength conditions of a tractive-transporting element under such conditions allows reasonable determination of a possibility of its further operation in a hoisting and transporting machine.

Determination of displacements in cross-sections of four-bar mechanism links from distributed dynamic loads and their animation using MAPLE

2018 ◽  
Vol 98 (2) ◽  
pp. 45-56
Author(s):  
М. U. Utenov ◽  
◽  
S. К. Zhilkibayeva ◽  
Zh. Zh. Baygunchekov ◽  
◽  
...  
Keyword(s):  
Cross Sections ◽  
Dynamic Loads

New in Old: Simplified Equations for Linear-elastic Symmetric Arches and Insights on Their Behavior

2020 ◽  
Vol 61 (3) ◽  
pp. 227-240
Author(s):  
Branko Glisic
Keyword(s):  
Cross Sections ◽  
Normal Force ◽  
Approximate Equation ◽  
Structural Behavior ◽  
Structural Systems ◽  
Linear Elastic ◽  
Wide Range ◽  
Different Types ◽  
Internal Forces

Closed-form equations for determination of reactions and internal forces of linear-elastic symmetric arches with constant cross-sections are derived. The derivation of the equations was initially made for segmental, threehinged, two-hinged, and hingeless arches. Not all derived equations are simple, but still not excessively complex to apply, and they reveal several new insights into the structural behavior of arches. The first is an extremely simple approximate equation for horizontal reactions of a hingeless arch under self-weight, which could be also applied with excellent accuracy to catenary and parabolic arches, and with a desirable level of accuracy to two- and three-hinged arches with a relatively wide range of geometries. The second insight is an approximately linear relationship between reactions and between internal forces of arches with different structural systems, which helps understand the global structural behavior of arches in a new way and enables inference of some other insights presented in the paper. The third insight reflects the relationships between normal force distribution and its eccentricity in different types of arches. Finally, the fourth insight regards the comparison of behavior of arches under the self-weight with those loaded with uniformly distributed load along their span.

Stress-Strain State of Reinforced Anisotropic Elements of Round and Annulus Section

2019 ◽  
Vol 968 ◽  
pp. 309-316
Author(s):  
Mechyslav Chekanovych ◽  
Svetlana Romanenko ◽  
Yanina Andriievska
Keyword(s):  
Cross Sections ◽  
Strain State ◽  
Recurrence Formula ◽  
Analytical Determination ◽  
State Equations ◽  
Stress Strain ◽  
Stress Strain State ◽  
Deformation Parameters ◽  
Stress And Deformation

The paper is dedicated to the analytical determination of stress and deformation parameters of reinforced anisotropic elements of round and annulus section, including columns, risers, supports, pipes, piles. The exact solution of stress-strain state equations for cross-sections of structures within initial data is performed on the basis of recurrence formula for integral of differential binominal.

Analysis of STEM micrographs of thick objects

1978 ◽  
Vol 36 (2) ◽  
pp. 106-107
Author(s):  
S. Golladay
Keyword(s):  
Inelastic Scattering ◽  
Multiple Scattering ◽  
Mass Distribution ◽  
Cross Sections ◽  
Phase Contrast ◽  
Image Point ◽  
Contrast Effects ◽  
Total Cross Sections ◽  
Elastic And Inelastic Scattering

The theory of multiple scattering has been worked out by Groves and comparisons have been made between predicted and observed signals for thick specimens observed in a STEM under conditions where phase contrast effects are unimportant. Independent measurements of the collection efficiencies of the two STEM detectors, calculations of the ratio σe/σi = R, where σe, σi are the total cross sections for elastic and inelastic scattering respectively, and a model of the unknown mass distribution are needed for these comparisons. In this paper an extension of this work will be described which allows the determination of the required efficiencies, R, and the unknown mass distribution from the data without additional measurements or models. Essential to the analysis is the fact that in a STEM two or more signal measurements can be made simultaneously at each image point.

A quantitative approach to inner shell losses

1978 ◽  
Vol 36 (1) ◽  
pp. 526-527 ◽  
Author(s):  
R.D. Leapman ◽  
P. Rez ◽  
D.F. Mayers
Keyword(s):  
Energy Transfer ◽  
Cross Section ◽  
Cross Sections ◽  
Accurate Determination ◽  
Background Intensity ◽  
Core Excitation ◽  
Quantitative Basis ◽  
Cross Section Differential ◽  
Bound Electrons

Microanalysis by EELS has been developing rapidly and though the general form of the spectrum is now understood there is a need to put the technique on a more quantitative basis (1,2). Certain aspects important for microanalysis include: (i) accurate determination of the partial cross sections, σx(α,ΔE) for core excitation when scattering lies inside collection angle a and energy range ΔE above the edge, (ii) behavior of the background intensity due to excitation of less strongly bound electrons, necessary for extrapolation beneath the signal of interest, (iii) departures from the simple hydrogenic K-edge seen in L and M losses, effecting σx and complicating microanalysis. Such problems might be approached empirically but here we describe how computation can elucidate the spectrum shape.The inelastic cross section differential with respect to energy transfer E and momentum transfer q for electrons of energy E0 and velocity v can be written as

Preparation And elemental analysis of ancient fibers

1987 ◽  
Vol 45 ◽  
pp. 410-411
Author(s):  
Allen Angel ◽  
Kathryn A. Jakes
Keyword(s):  
Cross Sections ◽  
Physical Structure ◽  
Energy Dispersive ◽  
Archaeological Sites ◽  
X Ray ◽  
Long Term Storage ◽  
Backscattered Electron ◽  
Electron Imaging

Fabrics recovered from archaeological sites often are so badly degraded that fiber identification based on physical morphology is difficult. Although diagenetic changes may be viewed as destructive to factors necessary for the discernment of fiber information, changes occurring during any stage of a fiber's lifetime leave a record within the fiber's chemical and physical structure. These alterations may offer valuable clues to understanding the conditions of the fiber's growth, fiber preparation and fabric processing technology and conditions of burial or long term storage (1).Energy dispersive spectrometry has been reported to be suitable for determination of mordant treatment on historic fibers (2,3) and has been used to characterize metal wrapping of combination yarns (4,5). In this study, a technique is developed which provides fractured cross sections of fibers for x-ray analysis and elemental mapping. In addition, backscattered electron imaging (BSI) and energy dispersive x-ray microanalysis (EDS) are utilized to correlate elements to their distribution in fibers.

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