scholarly journals Flexible stop’s force determining method in a combined plate using profiled flooring

Vestnik MGSU ◽  
2021 ◽  
pp. 997-1005
Author(s):  
Linur R. Gimranov ◽  
Alsou E. Fattakhova
Keyword(s):  
Computer Calculation ◽  
Existing Buildings ◽  
Joint Work ◽  
Steel Reinforced Concrete ◽  
Aspect Ratios ◽  
Cross Section Area ◽  
Solution Convergence ◽  
Section Area ◽  
Frame Buildings ◽  
Steel Frame Buildings

Introduction. Steel-reinforced concrete floors with profiled decking are most often used in steel frame buildings. The joint work of the floor slab and tertiary beam is ensured by shear studs. The article discusses a shear studs stress determining method from horizontal load. Studs are placed along the slab’s perimeter. The method based on the bolts’ group calculation analogy. Materials and methods. Based on the bolts group calculation design expressions were derived to determine the force in shear studs. To determine the obtained values reliability a finite element calculation was performed using the Lira-CAD software package. Different aspect ratios slabs samples were considered. The solution’s convergence was determined by various methods for a plate with 0.6 × 0.6 m dimensions with a small number of studs, after which the proposed solution convergence was studied for real dimensions of plates with a large number of flexible stops. Results. The resulting formula allows determining the stress in each flexible stop, in particular in the most loaded corner studs. The computer calculation was performed for the proposed method clarity and using possibility. The method’s use restriction was determined. In addition, the shear studs’ geometric characteristic’s definition explanations are given. Conclusions. The proposed calculation method allows to determinate any structural section’s shear stud’s stress. Therefore, it allows to choose stud’s optimal cross-section area or check its bearing capacity in the existing buildings and structures floors. Moreover, the stress value allows to determine the stud’s and a whole slab’s deformations.

First approximations to the energy release of giant dikes at Cerberus Fossae, Mars 

2021 ◽  
Author(s):  
Sam Rivas-Dorado ◽  
Javier Ruiz ◽  
Ignacio Romeo
Keyword(s):  
First Episode ◽  
Aspect Ratios ◽  
Cross Section Area ◽  
Section Area ◽  
Induced Fractures ◽  
Seismic Moment Release ◽  
Rock Mechanical Properties ◽  
Lower Size ◽  
Insight Mission ◽  
Cerberus Fossae

<p>Historical dike intrusions in the vicinity of volcanic edifices on Earth are known to produce swarms of seismic activity with cumulative seismic moments between 1·10<sup>12</sup> and 1·10<sup>20</sup> Nm, equivalent to moment magnitudes between 2 and 7. On Mars, long linear graben systems are likely to host giant dike complexes at depth, which possibly produced significant seismicity during their intrusion. Not only this, but dike intrusions are also candidates to produce crustal seismicity at present day, which may be detected during the lifespan of the InSight mission. In this work we infer the possible geometry of dikes underneath Cerberus Fossae, and make estimations of the energy released during their intrusion.</p><p>We used cross section area balancing on topographic profiles orthogonal to several of the Cerberus Fossae graben to estimate proxies for the geometry of the underlying dikes (aperture, height, depth, etc.). This technique has already been used to approximate dike properties at the nearby Elysium Fossae, with successful results. At Cerberus Fossae, the obtained dike aspect ratios are consistent with sublinear scaling, which is characteristic of fluid-induced fractures (as expected for dikes). These results support the presence of giant dikes underneath Cerberus, which may be up to 700 m thick, 140 km long, and have heights of up to 20 km.</p><p>Additionally, we used the inferred geometries and assumptions about the host rock mechanical properties to estimate various energy quantities related to dike intrusion, and compared them with the energy releases in terrestrial diking episodes. Two calculations are of special interest; M<sub>d</sub>, the energy associated to dike inflation, and M<sub>s</sub>, an approximation to the cumulative seismic moment release. The obtained M<sub>d</sub> values are between 3.1·10<sup>20</sup> and 5.0·10<sup>21</sup> Nm, and are 1 to 2 orders of magnitude larger than the equivalent moments in terrestrial events. M<sub>s</sub> was calculated from M<sub>d</sub> with two key assumptions; 1) that all aseismic energy was released by the dike, and 2) values of seismic efficiency (the percentage of seismic relative to the total energy released) based on terrestrial examples. The obtained M<sub>s</sub> are between 6.3·10<sup>19</sup> and 2.2·10<sup>21</sup> Nm, which are equivalent to moment magnitudes of 6.5 and 7.9. These are comparable to, albeit slightly larger than, the cumulative moments of some of the largest terrestrial diking events, such as the first episode in the Manda-Hararo sequence (Ethiopia, 2005, M<sub>s </sub>= 6.2) or the Miyake-jima event (Japan, 2000, M<sub>s </sub>= 6.8).</p><p>The Elysium volcanic province is thought to have been active until very recent times, and possibly even at present day. If this is the case, then intrusions in the lower size of the spectrum investigated at Cerberus, and smaller-sized events, may be detected by InSight as a series of crustal seismic events with cumulative moment magnitudes <6. Further research is needed to fully assess the validity of the comparisons between terrestrial and Martian events, and the possible energy releases of dike-induced marsquakes.</p>

Enhancement of Fluid Mixing in a Double T-Shaped Micromixer by Periodic Disturbances of Pressure

2011 ◽  
Vol 339 ◽  
pp. 118-123 ◽  
Author(s):  
Huan Chao Chiu ◽  
Jerry M Chen
Keyword(s):  
Reynolds Numbers ◽  
Mixing Efficiency ◽  
Low Reynolds Numbers ◽  
Periodic Disturbances ◽  
Side Channels ◽  
Aspect Ratios ◽  
Cross Section Area ◽  
Section Area ◽  
Channel Aspect Ratio ◽  
Phase Angles

This paper presents numerical simulations of mixing phenomena in a double T-shaped micromixer to which periodic pressure disturbances are added to enhance the mixing efficiency. The fluids were brought in contact at the upper T-junction. The pressure disturbances of various frequencies (0-50 Hz) and phase angles were introduced through the side channels of the lower T-structure. The simulations were carried out for microchannels having the same cross-section area but with different aspect ratios (1.6-10) at low Reynolds numbers (2.9-8.8). It is found that the mixing efficiency rapidly increases with an increase of the oscillation frequency in the lower range (0-8 Hz) to reach a maximum and then decreases in the higher frequency range except for the in-phase disturbance. The mixing is enhanced most significantly as the two pressure disturbances oscillate exactly out of phase. The effects due to channel aspect ratio and inlet velocity are also discussed.

On the Calibration of Irwin Probes for Flow in Rectangular Ducts With Different Aspect Ratios

2017 ◽  
Vol 139 (10) ◽  
Author(s):  
Raquel Faria ◽  
Almerindo D. Ferreira ◽  
A. M. G. Lopes ◽  
Antonio C. M. Sousa
Keyword(s):  
Experimental Data ◽  
Friction Coefficient ◽  
Turbulent Flow ◽  
Flow Region ◽  
Reynolds Numbers ◽  
Hydraulic Diameter ◽  
Equivalent Diameter ◽  
Aspect Ratios ◽  
Cross Section Area ◽  
Section Area

In this work, the suitability of pressure probes, commonly known as Irwin probes, to determine the local wall shear stress was evaluated for steady turbulent flow in rectangular ducts. Pressure measurements were conducted in the fully developed flow region of the duct and both the influence of duct aspect ratio (AR) (from 1:1.03 to 1:4.00) and Reynolds number (from 104 to 9 × 104) on the mean characteristics of the flow were analyzed. In addition, the sensitivity of the longitudinal and transversal placement of the Irwin probes was verified. To determine the most appropriate representation of the experimental data, three different characteristic lengths (l*) to describe Darcy's friction coefficient were investigated, namely: hydraulic diameter (Dh), square root of the cross section area (√A), and laminar equivalent diameter (DL). The comparison of the present experimental data for the range of tested Re numbers against the results for turbulent flow in smooth circular tubes indicates similar trends independently of the AR. The selection of the appropriate l* to represent the friction coefficient was found to be dependent on the AR of the duct, and the three tested scales present similar performance. However, the hydraulic diameter, being the commonly employed to compute turbulent flow in rectangular ducts, is the selected characteristic length scale to be used in the present study. A power function-based calibration equation is proposed for the Irwin probes, which is valid for the range of ARs and Reynolds numbers tested.

scholarly journals Calculations of the rigidity and the strength of concrete filled steel deck diaphragms

2021 ◽  
Vol 274 ◽  
pp. 03014
Author(s):  
Oleg Efimov ◽  
Linur Gimranov ◽  
Alsou Fattakhova
Keyword(s):  
Shear Stress ◽  
Shear Stresses ◽  
Horizontal Load ◽  
Joint Work ◽  
Shear Deformations ◽  
Floor Slabs ◽  
Frame Buildings ◽  
Steel Frame Buildings ◽  
Two Sides ◽  
Steel Deck

Calculations of horizontal loads such as wind are required even for low-rise buildings. With stores number increasing their influence increases. The horizontal loads are perceived by the flooring discs. Steelreinforced concrete floors with profiled decking are most often used in steel frame buildings. Floor slabs and frame’s joint work is ensured by shear studs. The article discusses a shear studs’ stress determining method from horizontal load. There are different slab supporting variants: slap supported on two sides and along slab's perimeter. The goal was to determine shear stress in each flexible stop. The tasks were solved by calculating and by computing. Then the results were compared. Therefore, the resulting formula allows determining shear stresses not only in square slab but in rectangular ones too. Shear stress knowledge in the studs allows to determinate frames’ displacements by horizontal loads. Frame displaces relative to the floor slab due to studs shear and flexibility. The derived displacements determining formula takes into account shear deformations and anchor compliance in different directions. Herewithin the article, proposed displacements formula is not checked, but only the components determining a method is proposed.

EFFECT OF BEDLOAD SEDIMENT NATURAL COMPOSITION ON GEOMETRIC AND DINAMIC CHARACTERISTICS OF CHANNEL FORMS

2018 ◽  
pp. 36-39
Author(s):  
N Ikramov ◽  
T Majidov
Keyword(s):  
Research Work ◽  
Laboratory Data ◽  
Hydroelectric Station ◽  
Negative Consequences ◽  
Movement Velocity ◽  
Reservoir Volume ◽  
Pump Station ◽  
Cross Section Area ◽  
Section Area ◽  
Bedload Sediment

The article brings up data on sediment diversity at watercourse bed and on their movement in the form of ridges. The ridge form movement of sediment leads to the reduction of reservoir volume and canal cross section area, which has an effect on their carrying capacity, filling of pump station forechambers and hydroelectric station pressure basins with sediment. The presence of sediment in flow leads to abrasive deterioration of pumps, water motors and pressure pipes and to other negative consequences. Research work tasks on the study of these effects have been examined with the purpose of preventing such negative consequences. On the basis of laboratory data diagrams and relationships were obtained for ridge length, height and movement velocity vs. sediment hydraulic and geometric sizes.

scholarly journals Long-term evaluation of rootstock effects on cropping and tree parameters of selected sweet cherry cultivars

2020 ◽  
Vol 47 (No. 1) ◽  
pp. 13-20
Author(s):  
Jitka Blažková ◽  
František Paprštein ◽  
Lubor Zelený ◽  
Adéla Skřivanová ◽  
Pavol Suran
Keyword(s):  
Sweet Cherry ◽  
Cross Section Area ◽  
Section Area ◽  
Natural Tendency ◽  
Term Evaluation ◽  
The Mean ◽  
Sweet Cherry Cultivars ◽  
Tree Characteristics ◽  
Gisela 5

The cropping of six sweet cherry cultivars that originated in the Research and Breeding Institute of Pomology at Holovousy, and a standard one, ‘Burlat’, were evaluated on three rootstocks in the period of 2007–2017. Trees planted in a spacing of 1.5 m × 5.0 m were trained as tall spindle axes utilising their natural tendency to develop a central leader. On the standard rootstock, P-TU-2, ‘Tim’ was the most productive with a mean total harvest of 47.6 kg per tree. ‘Sandra’ yielded the most on the PHLC rootstock with 56.2 kg per tree and ‘Helga’ yielded the most on Gisela 5 with a mean total harvest of 55.9 kg per tree. The mean impact of the rootstock on the tree vigour, measured upon the trunk cross section area, ranged from 148.4 cm2 on the standard rootstock P-TU-2 to 114.1 cm2 on the PHLC and 125.2 cm2 on Gisela 5 . On the standard rootstock P-TU-2, the most vigorous one according to this criterion was ‘Jacinta’ (178.0 cm2) whereas ‘Justyna’ (109.7 cm2) was the least vigorous. On the PHLC, the most vigorous was ‘Sandra’ (147.2 cm2) and the least was ‘Amid’ (94.0 cm2). The other tree characteristics were mainly dependant on the cultivar and minimally, or not at all, influenced by the rootstock vigour.

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