scholarly journals The Staple-Shape Plate Springs Engineering Calculation Method

2021 ◽  
Vol 20 (3) ◽  
pp. 268-274
Author(s):  
M. K. Sukach
Keyword(s):  
Cross Sections ◽  
Engineering Calculation ◽  
Middle Part ◽  
Leaf Spring ◽  
Elastic Suspension ◽  
Shock Absorbers ◽  
National University ◽  
Plate Spring ◽  
Load Action ◽  
The Moment

The new types of elastic devices – staple-shape plate spring and leaf spring - have been developed at the Kyiv National University of Construction and Architecture. The staple-shape plate spring is an elastic plate where the ends are deflected from its middle part in the same direction and are made in the form of consoles equipped with hinge attachments. The middle part of the plate as a parallel to the line of the load action is designed with variable length section. In each section, the axis, relative to which the moment of the section inertia is a maximum, is perpendicular to the spring bending plane, designed as the equal resistance beam. This article substantiates the feasibility of using a staple-shape plate spring to improve the elastic suspension of truck cabs. The recommendations for choosing the most promising mass production directions, as well as the engineering calculation methods of such springs, have been developed. Objects of the study are devices intended for machines and their components dynamic loads shock absorption, differing in having a bracket shape and being a subject to  bending in the plane of the highest rigidity of their cross sections, as well as shock absorbers using these springs, in particular KamAZ cabs suspension. This research implementation allows significantly reducing the metal consumption and elastic devices manufacture complexity, as well as can be useful in the design and operation of elastic car suspensions.Keywords: elastic device, staple-shaped plate spring, leaf spring, elastic suspension

scholarly journals APPLICATION OF DOMAIN INTEGRATED DESIGN METHODOLOGY FOR BIO-INSPIRED DESIGN- A CASE STUDY OF SUTURE PIN DESIGN

2021 ◽  
Vol 1 ◽  
pp. 487-496
Author(s):  
Pavan Tejaswi Velivela ◽  
Nikita Letov ◽  
Yuan Liu ◽  
Yaoyao Fiona Zhao
Keyword(s):  
Cross Sections ◽  
Design Methodology ◽  
Reaction Force ◽  
Integrated Design ◽  
Total Deformation ◽  
Insertion Force ◽  
Force Reaction ◽  
The Moment ◽  
Work Done

AbstractThis paper investigates the design and development of bio-inspired suture pins that would reduce the insertion force and thereby reducing the pain in the patients. Inspired by kingfisher's beak and porcupine quills, the conceptual design of the suture pin is developed by using a unique ideation methodology that is proposed in this research. The methodology is named as Domain Integrated Design, which involves in classifying bio-inspired structures into various domains. There is little work done on such bio-inspired multifunctional aspect. In this research we have categorized the vast biological functionalities into domains namely, cellular structures, shapes, cross-sections, and surfaces. Multi-functional bio-inspired structures are designed by combining different domains. In this research, the hypothesis is verified by simulating the total deformation of tissue and the needle at the moment of puncture. The results show that the bio-inspired suture pin has a low deformation on the tissue at higher velocities at the puncture point and low deformation in its own structure when an axial force (reaction force) is applied to its tip. This makes the design stiff and thus require less force of insertion.

Elastic Waves Created During Tensile Fracture: The Phenomenon of a Second Fracture

1953 ◽  
Vol 20 (1) ◽  
pp. 122-130
Author(s):  
Julius Miklowitz
Keyword(s):  
Cross Sections ◽  
Tensile Tests ◽  
Analog Computer ◽  
Tensile Fracture ◽  
Strain Waves ◽  
Unloading Wave ◽  
Second Fracture ◽  
Wave Compression ◽  
Initial Fracture ◽  
The Moment

Abstract In some tensile tests with brittle materials, it was noted that fractures were produced at two different cross sections of the specimen when the rupture load was reached. The phenomenon of the second fracture prompted the present investigation. It is believed that the second fracture is caused by the destructive action of the elastic strain waves created during the first of the two fractures. The analytical and experimental work carried out was focused on describing the character of these waves. Consideration of the mechanics involved reduces the problem to that of a vibrating cantilever beam with time-dependent boundary conditions. Two types of waves are shown to exist. The first is a longitudinal unloading wave (compression). The other is a group of flexural strain waves caused by the moment that develops at the initial fracture section. The methods of operational mathematics and the electric-analog computer have been employed in the analytical study.

scholarly journals Laryngeal Papillomatosis in Adults: Assessment for Ten Years at the ENT Department of the National University Hospital of Fann (Dakar, Senegal)

2020 ◽  
Vol 2020 ◽  
pp. 1-5
Author(s):  
N. Ndour ◽  
S. Maiga ◽  
A. Houra ◽  
R. E. A. Deguenonvo ◽  
C. Ndiaye ◽  
...  
Keyword(s):  
Benign Tumor ◽  
University Hospital ◽  
Malignant Degeneration ◽  
Age Group ◽  
Laryngeal Papillomatosis ◽  
Common Benign Tumor ◽  
National University ◽  
Laryngeal Dyspnea ◽  
The Mean ◽  
The Moment

Objectives. The aim of this study was to describe the epidemiological, diagnostic, and therapeutic aspects of adult laryngeal papillomatosis in Senegal. Patients and Methods. This is a retrospective descriptive study of patients aged above 18 years with laryngeal papillomatosis and followed at the ENT department of the NUH of Fann between 01 January 2009 and 31 December 2018. Results. The mean age at diagnosis was 37.74 years and a sex ratio of 0.93. The 20–29 age group was the most represented (45.2%). The average consultation delay was 8.34 years. All patients had dysphonia at the moment of the diagnostic and in 35.5% of cases, and it was associated with laryngeal dyspnea. Glottis localization was present in all our patients, i.e., 100% of the cases. A tracheotomy was performed in 9.67% of cases. All of our patients have had their papilloma peeled per endoscopic with tweezers. No cases of malignant degeneration were found in our study. Conclusion. Laryngeal papillomatosis is the most common benign tumor of the larynx in both children and adults. Despite the progress of endoscopy and antiviral treatments, its treatment poses many problems in our undermedicalized countries.

scholarly journals Premature destruction of two-span RC beams exposed to high temperature caused by a redistribution of shear forces

2016 ◽  
Vol 23 (4) ◽  
pp. 431-439 ◽  
Author(s):  
Robert KOWALSKI ◽  
Michał GŁOWACKI ◽  
Marian ABRAMOWICZ
Keyword(s):  
High Temperature ◽  
Cross Sections ◽  
Bending Moment ◽  
Middle Part ◽  
Transverse Reinforcement ◽  
Shear Load ◽  
Bending Moments ◽  
Rc Beams ◽  
Shear Forces ◽  
Load Bearing Capacity

When multi-span RC elements are exposed to fire one usually observes a yielding of span cross-sections while a safety reserve of support cross-sections is still significant. Due to this phenomenon a redistribution of bending moments occurs and the values of sagging moment in span cross-sections decrease while the values of hogging moment in support cross-sections increase. This paper shows the results of tests conducted on two-span RC beams in a situation when only one span has been exposed to high temperature from the bottom. The beams were 12×16 cm in their cross-section. The length of the span was 165 cm. The load has been applied by two forces put on each span. The beams were made of C25/30 concrete with siliceous aggregate. As a result of significant stiffness decrease of the heated span, redistribution of shear forces and bending moment occurs. Due to this redistribution the tested beams were prematurely damaged due to exhaust of the shear load bearing capacity in the middle part of the beam span where there was no transverse reinforcement.

The Brittleness of Ebonite

1937 ◽  
Vol 10 (4) ◽  
pp. 778-786
Author(s):  
R. Ariano
Keyword(s):  
Mechanical Properties ◽  
Cross Section ◽  
Cross Sections ◽  
Test Specimen ◽  
The State ◽  
The Other ◽  
Appreciable Effect ◽  
Considerable Influence ◽  
Minimum Depth ◽  
The Moment

Abstract The results of tests of the brittleness of ebonite are described. Resilience is influenced chiefly by the moment of inertia of the cross section of the test-specimen, but it seems also to be affected by the form of the specimen. The state of vulcanization has considerable influence on these mechanical properties within the undercured range, but with thorough vulcanization the state of cure plays no appreciable part. Notching of test-specimens is not of great importance. It diminishes the resilience, but when the tests are compared on a basis of equal moments of inertia of the resistant cross sections, this diminution becomes inappreciable in the case of brittle ebonites. On the other hand, the shape of the notch in ebonites containing no loading ingredients does influence the resilience. With V-shaped notches, the depth of the notch and its angle of aperture influence considerably the resilience of this latter type of ebonite, and notches of minimum depth are sufficient to have an appreciable effect.

Structure, strain and AMS of the Uzunakhmat thrust sheet (Talas Range, Kyrgyz North Tian Shan)

2020 ◽  
Author(s):  
Anastasia Kushnareva ◽  
Artem Moskalenko ◽  
Alexander Pasenko
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Structural Evolution ◽  
Middle Part ◽  
Tien Shan ◽  
Initial Shape ◽  
Thrust Sheet ◽  
Structural Style ◽  
Thrust Sheets ◽  
Tian Shan

<p>The Talas Range forms the northwest part of the Caledonides of the Northern Tian Shan. Based on differences in the structural style, metamorphism and sedimentary successions, three thrust sheets have been identified – the Uzunakhmat, Talas, and Kumyshtag thrust sheets. The Talas and Kumyshtag thrust sheets consist of Neoproterozoic-Ordovician terrigenous and carbonate rock units, whereas the Uzunakhmat thrust sheet consists of Neoproterozoic terrigenous rocks metamorphosed up to greenschist facies. The Uzunakhmat thrust sheet is separated from the Talas and Kumyshtag thrust sheets by the southwest-dipping Central Talas thrust (CTT). The dextral strike-slip Talas-Fergana Fault bounds the Uzunakhmat thrust sheet in the southwest. The main deformation events occurred in the Middle-Late Ordovician.</p><p>Structural and strain studies were done along profiles normal to the strike of folds and faults and located in the northwest and southeast parts of the Uzunakhmat thrust sheet. We also incorporate in our study structural profile in the central part of the Uzunakhmat thrust sheet, documented by Khudoley (1993) and Voytenko & Khudoley (2012).</p><p>The main strain indicators were detrital quartz grains in sandstones. Rf/φ and Normalized Fry methods were used to identify the amount of strain. Oblate ellipsoids predominate with Rxz values varying mostly from 1,6 to 2,4. Long axes of strain ellipsoids are sub-horizontal with the southeast to east-southeast trend. Similar trends have long axes of the anisotropy magnetic susceptibility ellipsoid being parallel to fold axes, cleavage-bedding intersection and mineral lineation as well as the trend of the major thrusts, including CTT.</p><p>The modern shape of the Uzunakhmat thrust sheet is similar to an elongated triangle, pinching out northwest and expanding southeast. Cross-section balancing corrected for the amount of strain shows along-strike decreasing of shortening in the southeast direction. Total shortening varies from 35% to 55% between sections located about 15 km from each other. Such significant variation in shortening corresponds to variation in structural style with much more tight folds and more numerous thrusts for cross-sections with a higher amount of shortening. However, the restored length of all cross-sections is quite similar pointing to the approximately rectangular initial shape of the Uzunakhmat thrust sheet. Our interpretation is that during the Caledonian tectonic events, the Uzunakhmat thrust sheet was displaced in the northwest direction with accompanied thrusting and folding of rock units within the thrust sheet. These deformations formed the modern shape of the thrust sheet in accordance with the amount of shortening detected by cross-section balancing. This interpretation also implies that modern erosion did not significantly affect shape of the Uzunakhmat thrust sheet formed after the Caledonian deformation.</p><p>Khudoley, A.K., 1993. Structural and strain analyses of the middle part of the Talassian Alatau ridge (Middle Asia, Kirgiystan). J. Struct. Geol. 6, 693–706.</p><p>Voytenko N.V., Khudoley A.K. Structural evolution of metamorphic rocks in the Talas Alatau, Tien Shan, Central Asia: Implication for early stages of the Talas-Ferghana Fault. // C. R. Geoscience. 2012. V. 344. P. 138–148.</p>

scholarly journals IV. On the practical solution of the most general problems in continuous beams

1879 ◽  
Vol 29 (196-199) ◽  
pp. 493-505
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
General Problem ◽  
Bending Moment ◽  
Moment Of Inertia ◽  
Shearing Stress ◽  
Practical Solution ◽  
Continuous Beams ◽  
The Moment

1. It is not necessary to enter into the question of the advisability of employing continuous girders in bridges with spans of less than 200 feet, but it is generally conceded that the increased economy due to the employment of continuous girders in longer spans more than counterbalances the well-known practical objections to continuity. Hence the practical solution of the general problem—given the conditions at the ends of a continuous girder, the spans, the moment of inertia of all cross sections, and the loading, to find the bending moment and shearing stress in every cross-section, is not unworthy of our attention.

scholarly journals Electron transport in silicon nanowires having different cross-sections

2016 ◽  
Vol 7 (2) ◽  
pp. 8-25 ◽  
Author(s):  
Orazio Muscato ◽  
Tina Castiglione
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Silicon Nanowires ◽  
Maximum Entropy Principle ◽  
Optical Phonons ◽  
Poisson System ◽  
Moment System ◽  
Entropy Principle ◽  
Closure Relations ◽  
The Moment

AbstractTransport phenomena in silicon nanowires with different cross-section are investigated using an Extended Hydrodynamic model, coupled to the Schrödinger-Poisson system. The model has been formulated by closing the moment system derived from the Boltzmann equation on the basis of the maximum entropy principle of Extended Thermodynamics, obtaining explicit closure relations for the high-order fluxes and the production terms. Scattering of electrons with acoustic and non polar optical phonons have been taken into account. The bulk mobility is evaluated for square and equilateral triangle cross-sections of the wire.

scholarly journals Application of UV-cured resin as embedding/mounting media for practical, time-saving otolith specimen preparation

2018 ◽  
Author(s):  
Carlos Augusto Strüssmann ◽  
Kaho Miyoshi ◽  
Shota Mitsui
Keyword(s):  
Cross Sections ◽  
Epoxy Resins ◽  
Specimen Preparation ◽  
Otolith Growth ◽  
Time Saving ◽  
Demographic Traits ◽  
Sound Detection ◽  
Otolith Core ◽  
The Moment ◽  
Microstructural Examination

AbstractOtoliths are calcified structures located in the inner ears of fish, as in most vertebrates, that are responsible primarily for the perception of gravity, balance and movement, and secondarily of sound detection. Microstructural and chemical analyzes of the inner otolith growth layers, called increments, constitute powerful tools to estimate fish age and elucidate many life history and demographic traits of fish populations. Otolith analyzes often require the production of a thin cross section that includes in the same plane of view the otolith core and all microscopic layers formed from birth until the moment of collection (otolith edge). Here we report on the usefulness of UV-cured resins that have become recently popular among nail artists and hobbyists for otolith specimen preparation. We show that single-component UV-cured resins can replace successfully and advantageously the commonly used two-component Epoxy resins to obtain otolith cross sections suitable for both microstructural examination and chemical analysis by electron probe microanalysis. UV-cured resins provide on-demand, extremely rapid (minute-order) hardening and high transparency, while providing similar adhesion and mechanical support for the otoliths during processing and analysis as Epoxy resins. UV-cured resins may revolutionize otolith specimen preparation practically- and time-wise, and may be particularly useful in teaching and workshop situations in which time for otolith embedding is a constraint.

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