scholarly journals Effective shaping of a bisymmetrical cross section of beams under shear stresses constraints

2021 ◽  
Vol 1199 (1) ◽  
pp. 012062
Author(s):  
K Magnucki ◽  
D Witkowski
Keyword(s):  
Objective Function ◽  
Cross Section ◽  
Analytical Study ◽  
Shear Stresses ◽  
Constraint Condition ◽  
Inertia Moment ◽  
The Subject ◽  
The Cross

Abstract The subject of the studies is effective shaping of an analytically defined, bisymmetrical cross section of beams. The objective function concerns the maximum of the inertia moment and minimum of the area of the cross section. The constraint condition takes into account the maximum shear stresses. The effective shapes of the exemplary beams are derived. Results of the analytical study are presented in Tables and Figures.

scholarly journals Progress in Measurements of 0.1–10 GeV Neutrino–Nucleus Scattering and Anticipated Results from Future Experiments

2018 ◽  
Vol 68 (1) ◽  
pp. 105-129 ◽  
Author(s):  
Kendall Mahn ◽  
Chris Marshall ◽  
Callum Wilkinson
Keyword(s):  
Cross Section ◽  
Neutrino Oscillation ◽  
Neutrino Interactions ◽  
Current State ◽  
Nucleus Scattering ◽  
The Subject ◽  
The Cross ◽  
Exotic Physics ◽  
Nuclear Targets

Neutrino interactions with nuclei have been the subject of intense interest during the last 15 years. Current and future measurements of neutrino oscillation and exotic physics use order 0.1–10 GeV neutrinos on a range of nuclear targets (12C,16O,40Ar). As the precision of these experiments has increased, information from their detectors and dedicated experiments has indicated deficiencies in the modeling of neutrino interactions on nuclear targets. Here, we present the current state of knowledge about neutrino–nucleus interactions, the challenge of extracting the cross section of these processes, and current experimental puzzles in the field. We also look forward to new and novel measurements and future efforts that seek to resolve these questions.

scholarly journals Optimization of the cross-sectional shape of the belts of trihedral lattice supports

2019 ◽  
Vol 7 (4) ◽  
pp. 5-8
Author(s):  
Linar Sabitov ◽  
Ilnar Baderddinov ◽  
Anton Chepurnenko
Keyword(s):  
Objective Function ◽  
Nonlinear Optimization ◽  
Cross Section ◽  
Optimization Methods ◽  
Cross Sectional ◽  
Maximum Value ◽  
Axial Moment ◽  
The Cross ◽  
Nonlinear Optimization Methods ◽  
Sectional Shape

The article considers the problem of optimizing the geometric parameters of the cross section of the belts of a trihedral lattice support in the shape of a pentagon. The axial moment of inertia is taken as the objective function. Relations are found between the dimensions of the pentagonal cross section at which the objective function takes the maximum value. We introduce restrictions on the constancy of the consumption of material, as well as the condition of equal stability. The solution is performed using nonlinear optimization methods in the Matlab environment.

scholarly journals ЩОДО ПИТАННЯ ПРО РАЦІОНАЛЬНУ ФОРМУ ПРЕСОВАНОГО БУЛЬБОКОСИНЦЯ

2020 ◽  
pp. 165-172
Author(s):  
А. Г. Дибир ◽  
А. А. Кирпикин ◽  
Н. И. Пекельный
Keyword(s):  
Service Life ◽  
Residual Stresses ◽  
Cross Section ◽  
Transverse Load ◽  
Shear Stresses ◽  
Cross Sectional ◽  
The Cross ◽  
Sectional Shape ◽  
Aircraft Panels ◽  
Better Than

In airplane building and helicopter engineering a bulb angle bar  an angle bar with a bulb at the end of a wall are widespread. They are better than a simple angle bar, since they have higher critical stresses under compression more than the proportionality limit. They are better than T bar, as T bar are fastened with two rows of rivets, which impairs tightness. Bulb angle bar are better than Z bar. The latter are higher, which reduces the structural height of the cross section and increases the load on the panel and usually have an excess cross-sectional area. Bulb angle bars are widely used in the structure of metal fuselages of airplanes and helicopters, in the tail boom of helicopters, in the wing and tail unit of light aircraft, in flaps, ailerons and rudders. However, modern the bulb angle bar have a significant drawback.When a bulb angle bar is loaded by a transverse load from the skin in the wing structure, tail unit, fuselage, except of normal stresses from bending of the stringer with attached skin, supported by ribs or frames, additional normal and shear torsional stresses arise. This torsion is caused by the fact that the lateral load is not applied at the center of the bend. Additional stresses reduce the service life and tightness of the structure in this place. An altered cross-sectional shape of the bulb is proposed for use in light aircraft panels to increase their strength and service life. The change in shape had a significant impact on the location of the center of the bend in the cross section. The determination of the position of the center of the bend in the balloncube was carried out using the Wagner model with walls not working for shear stresses. The modified cross-sectional shape of the bulbogon allowed to reduce the level of residual stresses after the panels were assembled, to rationally transfer the load from the casing to the stringer and to improve the technology of their assembly in the panels. It is recommended to drill holes for rivets in the stringer in the middle of the entire width of its shelf, taking into account the wall.A modified cross-sectional shape of a corner with bulb is proposed for use in light aircraft panels. The change in shape had a significant impact on the location of the center of the bend in the cross section. This made it possible to reduce the level of residual stresses after the assembly of the panels, to rationally transfer the load from the casing to the stringer and to improve the technology of their assembly.

The Cross-Section of the Semi-Rigid Airship

1930 ◽  
Vol 34 (236) ◽  
pp. 690-722
Author(s):  
F. G. Evans
Keyword(s):  
Cross Section ◽  
Graphical Method ◽  
Loading Conditions ◽  
Points Of Interest ◽  
Primary Object ◽  
The Subject ◽  
The Cross

The scope of the paper is not so wide as the title may suggest. The primary object is to put forward a graphical method of determining the shape of the cross-section of the airship, and the loads in the envelope and rigging wires, in the plane of the cross-section, for different loading conditions.Various secondary matters, such as a brief review of other methods of dealing with the subject, and the effect of different schemes of rigging on “ breathing,” are included in the paper as points of interest.

scholarly journals ASSESSMENT OF THE PROXIMITY OF DESIGN TO MINIMUM MATERIAL CAPACITY SOLUTION OF PROBLEM OF OPTIMIZATION OF THE FLANGE WIDTH OF I-SHAPED CROSS-SECTION RODS WITH ALLOWANCE FOR STABILITY CONSTRAINTS OR CONSTRAINTS FOR THE VALUE OF THE FIRST NATIONAL FREQUE

2020 ◽  
Vol 16 (2) ◽  
pp. 71-82 ◽  
Author(s):  
Leonid Lyakhovich ◽  
Pavel Akimov ◽  
Boris Tukhfatullin
Keyword(s):  
Objective Function ◽  
Natural Frequency ◽  
Cross Section ◽  
Wall Thickness ◽  
Optimal Solution ◽  
Computational Process ◽  
Flange Thickness ◽  
The Cross ◽  
Special Approach ◽  
Shaped Cross Section

There are known methods for optimizing the flange width of I-shaped cross-section rods with stability constraints or the constraints for the value of the first natural frequency. Corresponding objective function has the form of the volume of the flange material for the case when only the flange width varies and the cross-section height, wall thickness and flange thickness are specified. Special criterion for assessment of proximity of corresponding an optimal solution to the design of minimal material capacity was formulated for the considering problem. In this case, the resulting solution may not meet some other unaccounted constraints, for example, strength requirements. Modification of solution in order to meet previously unaccounted constraints does not allow researcher to consider such design as optimal. In the distinctive paper allowance for strength requirements, stability constraints or constraints for the value of the first natural frequency are proposed within considering problem of optimization. Special approach is formulated, which proposes to assess proximity to the design of minimum of material capacity obtained as a result of optimization. Increment of the objective function and criteria corresponding to constrains and restrictions are under consideration within computational process.

scholarly journals Flexural Behaviour of Lightweight Foamed Concrete Beams Reinforced with GFRP Bars

2018 ◽  
Vol 4 (2) ◽  
pp. 278 ◽  
Author(s):  
Suhad M Abd ◽  
Dhamyaa Ghalib
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Analytical Formula ◽  
Analytical Equation ◽  
Shear Stresses ◽  
Concentrated Load ◽  
Section Shape ◽  
Foamed Concrete ◽  
Show Difference ◽  
The Cross

A three meter-length cantilever beam loaded with a concentrated load at its free end is studied to determine shear stresses. In the present study, three cross sections are considered: rectangle (R); I, and T. The study presents a comparison of maximum shear stresses obtained by means of two methods: classical analytical equation derived by Collingnon, and finite element method (FEM) software. Software programs ANSYS and SAP2000 were used. The results show difference between the maximum shear stresses obtained by the analytical equation and the software, being the last is always higher. The average differences for ANSYS and SAP2000, independently of the cross section, were 12.76% and 11.96%, respectively. Considering these differences, correction factors were proposed to the classical analytical formula for each cross section case to obtain more realistic results. After the correction, the average differences decrease to 1.48% and 4.86%, regardless of the cross section shape.

scholarly journals Thermal Actions on the Materials During Deck and Pavement Construction

2018 ◽  
Vol 64 (4) ◽  
pp. 101-118
Author(s):  
B. Chmielewska ◽  
A. Garbacz ◽  
G. Adamczewski ◽  
B. Rymsza
Keyword(s):  
Cross Section ◽  
Bridge Deck ◽  
Asphalt Pavements ◽  
Gas Emission ◽  
Temperature Changes ◽  
Gaseous Products ◽  
Bituminous Materials ◽  
The Subject ◽  
The Cross ◽  
Pavement Construction

AbstractThe article presents the results of the research on thermal actions on the materials occurring in the cross section along the depth of the bridge deck and bituminous pavement during its construction. The impulse to curried out the research was the need to explain the causes of the blistering of bituminous waterproofing membranes and asphalt pavements often observed on the bridge decks. The paper presents the examples of such failures and the analyses of possible mechanisms of the phenomenon. Research indicates a significant influence of all technological processes on the temperature of materials in the cross section as well as daily temperature changes. The probability of initiation of reactions between concrete components with gaseous products has been confirmed in such conditions. The susceptibility of bituminous materials to gas emission and blistering is the subject of a separate study. The research was part of a research project carried out under the contract INNOTECHK3/IN3/50/229332 /NCBR /14 [13].

Experimental and Analytical Study of Gas Resonance Oscillations in the Closed Tube with the Cross-Section Jump

2021 ◽  
Vol 42 (9) ◽  
pp. 2135-2139
Author(s):  
D. A. Gubaidullin ◽  
L. A. Tkachenko ◽  
L. R. Shaidullin ◽  
A. A. Kabirov
Keyword(s):  
Cross Section ◽  
Analytical Study ◽  
Closed Tube ◽  
The Cross ◽  
Resonance Oscillations

scholarly journals On the distribution of velocity in a viscous fluid over the cross-section of a pipe, and on the action at the critical velocity

1905 ◽  
Vol 76 (509) ◽  
pp. 205-216 ◽  
Keyword(s):  
Viscous Fluid ◽  
Velocity Distribution ◽  
Critical Velocity ◽  
Cross Section ◽  
Viscous Fluids ◽  
Stream Line ◽  
The Subject ◽  
The Cross ◽  
The Stability ◽  
Lord Kelvin

1. Introduction .—An expression for the velocity at which stream-line motion breaks down in cylindrical pipes has been obtained by Osborne Reynolds, and together with many others he has measured the fall of pressure occurring in different lengths. Lord Kelvin, Lord Rayleigh, and Reynolds have investigated the stability of different kinds of flow for viscous and non-viscous fluids, but how nearly the theoretical conditions of velocity distribution actually occur has not hitherto formed the subject of research. Experiments have often been made on the variation of mean linear velocities in the eddying state, but when the motion is irrotational, these are too low to admit of accurate measurement by any method so far employed. The objects of the present paper are to determine these velocities, to investigate the change which takes place at the critical velocity, and to find the relation between the velocity and the pressure to which it gives rise in a “ Pitot ” gauge of the form used.

scholarly journals Determining Optimal Gear Ratios of a Two-stage Helical Reducer for Getting Minimal Acreage of Cross Section

2018 ◽  
Vol 213 ◽  
pp. 01008 ◽  
Author(s):  
Nguyen Khac Tuan ◽  
Vu Ngoc Pi ◽  
Nguyen Thi Hong Cam ◽  
Tran Thi Phuong Thao ◽  
Ho Ky Thanh ◽  
...  
Keyword(s):  
Computer Program ◽  
Objective Function ◽  
Cross Section ◽  
Equilibrium Condition ◽  
Optimization Problem ◽  
Design Equation ◽  
Two Stage ◽  
Moment Equilibrium ◽  
The Cross ◽  
Optimal Calculation

This article introduces a study on the optimal calculation of gear ratios of a two-stage helical reducer. In the study, the acreage of the cross section of the reducer was chosen as the objective function of the optimization problem. Also, the design equation for pitting resistance of a gear set was investigated. Furthermore, the equations on moment equilibrium condition of a two-stage helical reducer and their regular resistance condition were analysed. A computer program was performed to determine the optimal partial transmission ratios for getting the minimal acreage of the cross section of the system. From the results of the computer program, two models for determining the optimal gear ratios of a two-stage reducer were proposed. Using these models, the gear ratios can be calculated accurately in a simple way.

Sign in / Sign up

Export Citation Format

Share Document