scholarly journals EFFECT OF MICROSTRUCTURE OF CARDBOARD ON ITS MECHANICAL PROPERTIES

2021 ◽  
pp. 361-371
Author(s):  
Nikolay Petrovich Midukov ◽  
Viktor Sergeyevich Kurov
Keyword(s):  
Mechanical Properties ◽  
Cross Sections ◽  
Contact Lines ◽  
Modern Computer ◽  
Fiber Contact ◽  
Breaking Length ◽  
The Cross ◽  
Prediction Of Mechanical Properties ◽  
Almost All ◽  
Compression Resistance

The article is devoted to the prediction of mechanical properties on the study of the microstructure of the cross section of cardboard. The results of the work in the future can be used as an addition to standard methods for evaluating the mechanical properties of cardboard. On the basis of images of the microstructure of the cross sections of the two-layer test liner cardboard and their graphic processing using modern computer programs, the lengths of fiber contacts were determined. Guided by the fact that the most significant indicator of all geometric parameters of the microstructure is the length of fiber contacts, the main mechanical properties of cardboard were determined (bursting strength and compression resistance, breaking length, bending stiffness, interlayer strength)produced according to various technologies (conventional method of preparing recovered paper stock, dry defibration of recovered paper with aerodynamic formation of the top layer, dry defibration of recovered paper with subsequent supply of fibers to the stock and dry defibration of recovered paper with subsequent grinding in the stock). Each of the technologies allows to obtain cardboard with different mechanical parameters. It has been established that almost all mechanical indicators depend directly proportionally on the length of the fiber contact lines. The obtained dependencies can be used to predict the mechanical properties of cardboard in its production at industry enterprises.

Comparison of the Cross Sectional Area, the Loss in Volume and the Mechanical Properties of LAE442 and MgCa0.8 as Resorbable Magnesium Alloy Implants after 12 Months Implantation Duration

2010 ◽  
Vol 638-642 ◽  
pp. 675-680 ◽  
Author(s):  
Martina Thomann ◽  
Nina von der Höh ◽  
Dirk Bormann ◽  
Dina Rittershaus ◽  
C. Krause ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cross Sections ◽  
Degradation Process ◽  
Cross Sectional Area ◽  
Bending Test ◽  
Sectional Area ◽  
Cross Sectional ◽  
Initial Strength ◽  
Three Point Bending ◽  
The Cross

Current research focuses on magnesium based alloys in the course of searching a resorbable osteosynthetic material which provides sufficient mechanical properties besides a good biocompatibility. Previous studies reported on a favorable biocompatibility of the alloys LAE442 and MgCa0.8. The present study compared the degradation process of cylindrical LAE442 and MgCa0.8 implants after 12 months implantation duration. Therefore, 10 extruded implants (2.5 x 25 mm, cross sectional area 4.9 mm²) of both alloys were implanted into the medullary cavity of both tibiae of rabbits for 12 months. After euthanization, the right bone-implant-compound was scanned in a µ-computed tomograph (µCT80, ScancoMedical) and nine uniformly distributed cross-sections of each implant were used to determine the residual implants´ cross sectional area (Software AxioVisionRelease 4.5, Zeiss). Left implants were taken out of the bone carefully. After weighing, a three-point bending test was carried out. LAE442 implants degraded obviously slower and more homogeneously than MgCa0.8. The mean residual cross sectional area of LAE442 implants was 4.7 ± 0.07 mm². MgCa0.8 showed an area of only 2.18 ± 1.03 mm². In contrast, the loss in volume of LAE442 pins was more obvious. They lost 64 % of their initial weight. The volume of MgCa0.8 reduced clearly to 54.4 % which corresponds to the cross sectional area results. Three point bending tests revealed that LAE442 showed a loss in strength of 71.2 % while MgCa0.8 lost 85.6 % of its initial strength. All results indicated that LAE442 implants degraded slowly, probably due to the formation of a very obvious degradation layer. Degradation of MgCa0.8 implants was far advanced.

Finite Element Analysis of Concrete Frames after Fire with Fiber Model

2012 ◽  
Vol 193-194 ◽  
pp. 372-378 ◽  
Author(s):  
Min Xia ◽  
Jiang Tao Yu ◽  
Zhou Dao Lu ◽  
Li Wen Zhang
Keyword(s):  
Mechanical Properties ◽  
Cross Sections ◽  
Temperature Fields ◽  
Structural Members ◽  
Concrete Frames ◽  
Element Analysis ◽  
Fiber Model ◽  
Concrete Frame ◽  
Residual Mechanical Properties ◽  
The Cross

In order to analyze the residual mechanical properties of concrete frame structures after fire, a novel numerical model considering the distribution of non-uniform temperature in the cross-sections of structural members and the changing of mechanical properties of materials damaged by fire is developed in this paper by dividing the cross-sections of structural members into a lot of concrete fibers and steel fibers based on the concept of fiber model. Besides, the Analytical System of Fire-damaged Concrete Frame (ASFCF) is established through the secondary development of ABAQUS Software that is completed by the programming language of Python. This system is used to analyze the temperature fields and the nonlinear mechanical performances of a multi-story, multi-span, three-dimensional concrete frame after fire. The results indicate that ASFCF can properly analyze the mechanical properties of concrete frames after fire, and it provides valuable references for assessing the residual mechanical properties of concrete frames after fire.

scholarly journals Cross-Sectional Performance of Hollow Square Prisms with Rounded Edges

Symmetry ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 996
Author(s):  
Hiroyuki Shima ◽  
Nao Furukawa ◽  
Yuhei Kameyama ◽  
Akio Inoue ◽  
Motohiro Sato
Keyword(s):  
Mechanical Properties ◽  
Mathematical Model ◽  
Cross Sections ◽  
Cross Sectional ◽  
Hollow Section ◽  
Buckling Resistance ◽  
The Cross ◽  
The Stability ◽  
External Forces ◽  
Sectional Shape

Hollow-section columns are one of the mechanically superior structures with high buckling resistance and high bending stiffness. The mechanical properties of the column are strongly influenced by the cross-sectional shape. Therefore, when evaluating the stability of a column against external forces, it is necessary to reproduce the cross-sectional shape accurately. In this study, we propose a mathematical method to describe a polygonal section with rounded edges and vertices. This mathematical model would be quite useful for analyzing the mechanical properties of plants and designing plant-mimicking functional structures, since the cross-sections of the actual plant culms and stems often show rounded polygons.

Numerical Analysis and Simulation of Spatial Concrete Frames after Fire

2012 ◽  
Vol 204-208 ◽  
pp. 3423-3432
Author(s):  
Min Xia ◽  
Jiang Tao Yu ◽  
Zhou Dao Lu
Keyword(s):  
Mechanical Properties ◽  
Cross Sections ◽  
Numerical Models ◽  
Element Model ◽  
Frame Structures ◽  
Slab Thickness ◽  
Fire Damage ◽  
Concrete Frames ◽  
Concrete Frame ◽  
The Cross

In order to analyze the mechanical properties under three conditions of fire-damage, rehabilitation and strengthening of spatial concrete frame structures after fire, two novel numerical models are developed in this paper by dividing the cross-sections of beams and columns into a lot of concrete fibers and steel fibers and dividing slabs into several layers along the direction of the slab thickness based on the concept of the fiber element model and the layered shell element model. These two models can consider the distribution of non-uniform temperature in the cross-sections of structural members and the changing of mechanical properties of fire-damaged, rehabilitated and strengthened materials. Besides, the Analytical System of Fire-damaged Concrete Frame (ASFCF) is established through the secondary development of ABAQUS Software that is completed by the programming language of Python. This system is used to analyze and compare the mechanical responses under three conditions of fire-damage, rehabilitation and strengthening of a multi-story, multi-span spatial concrete frame after fire. The results indicate that ASFCF can properly analyze the mechanical properties under three conditions of fire-damage, rehabilitation and strengthening of spatial concrete frames after fire, and it provides valuable references for assessing the residual mechanical properties and the mechanical properties after rehabilitation and strengthening of global concrete frame structures after fire.

The cross sections for different channels in heavy ion nuclear reactions

1971 ◽  
Vol 32 (1) ◽  
pp. 7-9 ◽  
Author(s):  
J. Galin ◽  
D. Guerreau ◽  
M. Lefort ◽  
X. Tarrago
Keyword(s):  
Cross Sections ◽  
Nuclear Reactions ◽  
Heavy Ion ◽  
The Cross

Experimental Studies Of Multilayer Glass Structures On Compression, Compression With Bending And Simple Bending

2019 ◽  
pp. 22-30
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Applied Load ◽  
Experimental Studies ◽  
Strength Properties ◽  
Research Topic ◽  
Normative Values ◽  
Laminated Glass ◽  
The Cross ◽  
Experimental Values

The work of multilayer glass structures for central and eccentric compression and bending are considered. The substantiation of the chosen research topic is made. The description and features of laminated glass for the structures investigated, their characteristics are presented. The analysis of the results obtained when testing for compression, compression with bending, simple bending of models of columns, beams, samples of laminated glass was made. Overview of the types and nature of destruction of the models are presented, diagrams of material operation are constructed, average values of the resistance of the cross-sections of samples are obtained, the table of destructive loads is generated. The need for development of a set of rules and guidelines for the design of glass structures, including laminated glass, for bearing elements, as well as standards for testing, rules for assessing the strength, stiffness, crack resistance and methods for determining the strength of control samples is emphasized. It is established that the strength properties of glass depend on the type of applied load and vary widely, and significantly lower than the corresponding normative values of the strength of heat-strengthened glass. The effect of the connecting polymeric material and manufacturing technology of laminated glass on the strength of the structure is also shown. The experimental values of the elastic modulus are different in different directions of the cross section and in the direction perpendicular to the glass layers are two times less than along the glass layers.

scholarly journals Total cross sections of eγ → $$ eX\overline{X} $$ processes with X = μ, γ, e via multiloop methods

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Roman N. Lee ◽  
Alexey A. Lyubyakin ◽  
Vyacheslav A. Stotsky
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Elliptic Integral ◽  
High Energy ◽  
Calculation Methods ◽  
Complete Elliptic Integral ◽  
Total Cross Sections ◽  
Multiloop Calculation ◽  
The Cross ◽  
Analytical Expressions

Abstract Using modern multiloop calculation methods, we derive the analytical expressions for the total cross sections of the processes e−γ →$$ {e}^{-}X\overline{X} $$ e − X X ¯ with X = μ, γ or e at arbitrary energies. For the first two processes our results are expressed via classical polylogarithms. The cross section of e−γ → e−e−e+ is represented as a one-fold integral of complete elliptic integral K and logarithms. Using our results, we calculate the threshold and high-energy asymptotics and compare them with available results.

Sign in / Sign up

Export Citation Format

Share Document