scholarly journals Sprinkler droplet impact angle affects shear stress distribution on soil surface – a case study of a ball-driven sprinkler

2021 ◽  
Author(s):  
Xin Hui ◽  
Haijun Yan ◽  
Yuncheng Xu ◽  
Haibin Tan
Keyword(s):  
Shear Stress ◽  
Soil Erosion ◽  
Stress Distribution ◽  
Sprinkler Irrigation ◽  
Impact Angle ◽  
Droplet Impact ◽  
Nozzle Diameter ◽  
Shear Stresses ◽  
Operating Pressure ◽  
Impact Angles

Abstract Droplet shear stress is the main cause of soil erosion under sprinkler irrigation, and the effect of droplet impact angle on the shear stress distribution cannot be ignored. In this study, a ball-driven sprinkler was selected to investigate the radial distributions of droplet impact angles under three operating pressures (0.25, 0.30, and 0.35 MPa) and two nozzle diameters (1.9 and 2.2 mm), which are commonly used in agricultural irrigation. The effect of droplet impact angles on the distances from the sprinkler, droplet impact velocities, and shear stresses were analyzed by a 2DVD instrument. Irrespective of the nozzle diameter or operating pressure, the droplet velocities and impact angles near the sprinkler were distributed at 1.0–5.5 m s−1 and 70–90°, respectively, and the droplet shear stress increased with the distance from the sprinkler. Suitable operating pressure and distance from the sprinkler significantly reduced the droplet shear stress. Although the nozzle diameter had a certain effect on the maximum shear stress, the overall effect was insignificant. We developed the models for the radial distribution of droplet shear stresses, which were in good agreement with the measurement. This study proposes a new method for accurately predicating the soil erosion under sprinkler irrigation.

scholarly journals Assessing Machine Learning versus a Mathematical Model to Estimate the Transverse Shear Stress Distribution in a Rectangular Channel

Mathematics ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 596
Author(s):  
Babak Lashkar-Ara ◽  
Niloofar Kalantari ◽  
Zohreh Sheikh Khozani ◽  
Amir Mosavi
Keyword(s):  
Shear Stress ◽  
Stress Distribution ◽  
Fuzzy Inference ◽  
Rectangular Channel ◽  
Tsallis Entropy ◽  
Shear Stress Distribution ◽  
Data Series ◽  
Shear Stresses ◽  
Inference System ◽  
Aspect Ratios

One of the most important subjects of hydraulic engineering is the reliable estimation of the transverse distribution in the rectangular channel of bed and wall shear stresses. This study makes use of the Tsallis entropy, genetic programming (GP) and adaptive neuro-fuzzy inference system (ANFIS) methods to assess the shear stress distribution (SSD) in the rectangular channel. To evaluate the results of the Tsallis entropy, GP and ANFIS models, laboratory observations were used in which shear stress was measured using an optimized Preston tube. This is then used to measure the SSD in various aspect ratios in the rectangular channel. To investigate the shear stress percentage, 10 data series with a total of 112 different data for were used. The results of the sensitivity analysis show that the most influential parameter for the SSD in smooth rectangular channel is the dimensionless parameter B/H, Where the transverse coordinate is B, and the flow depth is H. With the parameters (b/B), (B/H) for the bed and (z/H), (B/H) for the wall as inputs, the modeling of the GP was better than the other one. Based on the analysis, it can be concluded that the use of GP and ANFIS algorithms is more effective in estimating shear stress in smooth rectangular channels than the Tsallis entropy-based equations.

scholarly journals Shear Stress Distribution in the Opening Chords of Hybrid R/C T-Beams with Opening

2018 ◽  
Vol 147 ◽  
pp. 01005
Author(s):  
Jonie Tanijaya
Keyword(s):  
Shear Stress ◽  
Stress Distribution ◽  
Shear Force ◽  
Maximum Shear Stress ◽  
Shear Stress Distribution ◽  
Shear Stresses ◽  
Web Openings ◽  
The Right ◽  
Lower Corner ◽  
T Beam

This study is carried out to evaluate the potential of three hybrid T-beams with web openings theoretical shear stresses distribution. The shear stresses at the opening edges were plotted at the working stage, yielding stage and collapse stage for these three tested beams. The available experimental results from the previous research was compared to the finite element results as well as the developed analytical. The shear stress distribution at the middle of the top and bottom chords of the opening in pure bending region are zero. At the upper and lower corners of the opening occurs the maximum shear stresses. The maximum shear stress occurs at the right lower corner chord at the high moment edge and at the left upper corner chord at the low moment edge in beams with openings at high shear and high flexural – shear region. Furthermore, an extensive parametric study is performed on these beams to find the distributing ratio of the shear force between the opening chords. The shear force at an opening in hybrid R/C T-beam is carried by the top and bottom chords of the opening according to the area – moment of inertia root ratio with the correction factor 0.70.

Effect of Combination Factors of Operating Pressure, Nozzle Diameter and Riser Height on Sprinkler Irrigation Uniformity

2014 ◽  
Vol 695 ◽  
pp. 380-383 ◽  
Author(s):  
Manal Osman ◽  
Suhaimi B. Hassan ◽  
Khamaruzaman B. Wan Yusof
Keyword(s):  
Irrigation System ◽  
Sprinkler Irrigation ◽  
Nozzle Diameter ◽  
Operating Pressure ◽  
Irrigation Uniformity ◽  
Distribution Uniformity ◽  
Coefficient Of Uniformity ◽  
Riser Height ◽  
Design Factors ◽  
Pressure Nozzle

The irrigation uniformity of sprinkler irrigation system depends on many design factors such as nozzle type, nozzle diameter, operating pressure and riser height. An experimental study was performed to investigate the effect of combination factors of operating pressure, nozzle diameter and riser height on sprinkler irrigation uniformity. Different operating pressures, nozzle diameters and riser heights have been used. The irrigation uniformity coefficients such as coefficient of uniformity (CU) and distribution uniformity of low quarter (DUlq) have been studied. This study concluded that, the irrigation uniformity of sprinkler irrigation system was more affected by the combination of operating pressure, nozzle diameter and riser height.

The Fluid Shear Stress Distribution on the Membrane of Leukocytes in the Microcirculation

2003 ◽  
Vol 125 (5) ◽  
pp. 628-638 ◽  
Author(s):  
Masako Sugihara-Seki ◽  
Geert W. Schmid-Scho¨nbein
Keyword(s):  
Shear Stress ◽  
Stress Distribution ◽  
Fluid Shear Stress ◽  
Cell Function ◽  
Shear Stress Distribution ◽  
Shear Stresses ◽  
Fluid Shear ◽  
Stress Gradients ◽  
Freely Suspended ◽  
Microvessel Wall

Recent in-vivo and in-vitro evidence indicates that fluid shear stress on the membrane of leukocytes has a powerful control over several aspects of their cell function. This evidence raises a question about the magnitude of the fluid shear stress on leukocytes in the circulation. The flow of plasma on the surface of a leukocyte at a very low Reynolds number is governed by the Stokes equation for the motion of a Newtonian fluid. We numerically estimated the distribution of fluid shear stress on a leukocyte membrane in a microvessel for the cases when the leukocyte is freely suspended, as well as rolling along or attached to a microvessel wall. The results indicate that the fluid shear stress distribution on the leukocyte membrane is nonuniform with a sharp increase when the leukocyte makes membrane attachment to the microvessel wall. In a microvessel (10 μm diameter), the fluid shear stress on the membrane of a freely suspended leukocyte (8 μm diameter) is estimated to be several times larger than the wall shear stress exerted by the undisturbed Poiseuille flow, and increases on an adherent leukocyte up to ten times. High temporal stress gradients are present in freely suspended leukocytes in shear flow due to cell rotation, which are proportional to the local shear rate. In comparison, the temporal stress gradients are reduced on the membrane of leukocytes that are rolling or firmly adhered to the endothelium. High temporal gradients of shear stress are also present on the endothelial wall. At a plasma viscosity of 1 cPoise, the peak shear stresses for suspended and adherent leukocytes are of the order of 10 dyn/cm2 and 100 dyn/cm2, respectively.

Erosion-Abrasion Behavior of Eutectic Al-Mn Alloy Matrix Composites Reinforced with Al2O3 Particulates

2010 ◽  
Vol 152-153 ◽  
pp. 1054-1057
Author(s):  
Bing Liu ◽  
Xin Mei Li ◽  
Xiang Liu ◽  
Chun Yao Wang
Keyword(s):  
Solid Solution ◽  
Shear Stress ◽  
Impact Angle ◽  
Matrix Composites ◽  
Alloy Matrix ◽  
Abrasion Test ◽  
Wear Rates ◽  
Impact Angles ◽  
The Impact ◽  
Worn Surface

Effects of different impact angles such as 45°and 90°on the erosion-abrasion properties of eutectic Al-Mn alloy and its composites reinforced with Al2O3 particulates were studied by rotating erosion-abrasion test, and the microstructure and the worn surfaces were analyzed. The results show that the as-cast Al-Mn alloy is composed of aluminium-manganese solid solution, MnAl6 and Al11Mn4 phase, while the δ-Al2O3 particles are included in the composites besides the aforementioned microstructures. With elongating the erosion time, the wear rates of the Al-Mn alloy and its composites increase at the impact angle of 90°, whereas they firstly increase and then decrease , and there is a maximum at 45°. The distortion wear caused by the normal stress is dominant at 90°, which lead to the erosion pits on the worn surface. However, the cutting wear by the shear stress is predominant at 45°, which result in the ploughs.

Numerical Analysis of Shear Stress on Adhesive Joint between FRP and Steel Structure in Civil Engineering

2012 ◽  
Vol 568 ◽  
pp. 216-221
Author(s):  
Shu Kuan Zhang ◽  
Pei Yan Huang ◽  
Hao Zhou ◽  
Chuan Yu Zhao
Keyword(s):  
Shear Stress ◽  
Stress Distribution ◽  
Adhesive Joint ◽  
Civil Engineering ◽  
Great Influence ◽  
Steel Structure ◽  
High Strength ◽  
Shear Stress Distribution ◽  
Shear Stresses ◽  
Accurate Analysis

Fiber reinforced polymer (FRP) is widely applied in the concrete and steel structure reinforcement field because of its high strength and convenient constructability in civil engineering. The adhesive joint is the weakness of the reinforced structure, but with the complicated stress distribution for analytic method. Numerical method provides the best solution to the further analysis. In this paper, a finite element method (FEM) of double lap joint model was established with ANSYS to investigate the shear stress in the adhesive joint of the reinforced structure, the shear stresses were analyzed in detail in both length and thickness direction in civil engineering. The results show that, 1) the FEM calculation results of shear stress of adhesive and the theoretical calculation values are consistent within the main part of the adhesive; 2) FEM is the effective method to further study the shear stress distribution of the adhesive, meshing size has great influence on the results of calculation; 3) to obtain more accurate analysis of shear stress distribution, the non-linear characteristics of the adhesive should be considered

Numerical Study of Cruciform Specimens for Biaxial Tensile Tests

2016 ◽  
Author(s):  
Luis F. Puente Medellín ◽  
Antonio Balvantin ◽  
J. A. Diosdado-De la Peña
Keyword(s):  
Shear Stress ◽  
Stress Distribution ◽  
Normal Stress ◽  
Sheet Metal ◽  
Numerical Study ◽  
Tensile Tests ◽  
Thickness Reduction ◽  
Shear Stresses ◽  
Normal Stress Distribution ◽  
Biaxial Tensile

This paper presents a numerical study of different geometries of cruciform specimens for biaxial tensile tests. The aim of these specimens is to be used on fixtures for biaxial tests mounted in universal testing machines. For the study, a model of isotropic material for steel sheet metal specimens was considered. Thus, only the mechanical properties of the sheet metal in the rolling direction were considered in the simulations. In this numerical analysis, the normal stress distribution and the consequent shear stress were studied. Additionally, the effect of the inclusion of multiple slots as well as a thickness reduction on the normal and shear stresses were assessed. Hence, a specimen in which a uniform normal stress distribution with zero shear stress, is necessary. The results of the analysis show that a specimen with features, multiple slots and a thickness reduction in the central area, provides a better performance in the simulations than dismissing any of these characteristics. Finally, a specimen model suitable for the mentioned test is proposed according to the obtained numerical results and the feasibility of manufacture of the experimental sample-test.

scholarly journals Assessing Machine Learning versus Mathematical Modeling to Estimate the Transverse Shear Stress Distribution in a Rectangular Channel

2021 ◽  
Author(s):  
Lashkar-Ara ◽  
Niloofar Kalantari ◽  
Zohreh Sheikh Khozani ◽  
Amir Mosavi
Keyword(s):  
Shear Stress ◽  
Stress Distribution ◽  
Fuzzy Inference ◽  
Rectangular Channel ◽  
Tsallis Entropy ◽  
Shear Stress Distribution ◽  
Data Series ◽  
Shear Stresses ◽  
Inference System ◽  
Aspect Ratios

One of the most important subjects of hydraulic engineering is the reliable estimation of the transverse distribution in rectangular channel of bed and wall shear stresses. This study makes use of the Tsallis entropy, Genetic Programming (GP) and adaptive neuro-fuzzy inference system (ANFIS) methods to assess the shear stress distribution (SSD) in rectangular channel. To evaluate the results of the Tsallis entropy, GP and ANFIS models, laboratory observations were used in which shear stress was measured using an optimized Preston tube. This is then used to measure the SSD in various aspect ratios in the rectangular channel. To investigate the shear stress percentage, 10 data series with a total of 112 different data for were used. The results of the sensitivity analysis show that the most influential parameter for the SSD in smooth rectangular channel is the di-mensionless parameter B/H, Where the transverse co-ordinate is B, and the flow depth is H. With the parameters (b/B), (B/H) for the bed and (z/H), (B/H) for the wall as inputs, the modeling of the GP was better than the other one. Based on the analysis, it can be concluded that the use of GP and ANFIS algorithms is more effective in estimating shear stress in smooth rectangular channels than the Tsallis entropy-based equations.

Shear Stresses in Bulk Carriers Due to Shear Loading

1975 ◽  
Vol 19 (03) ◽  
pp. 155-163
Author(s):  
M. A. Shama
Keyword(s):  
Shear Stress ◽  
Stress Distribution ◽  
Structural Model ◽  
Maximum Shear Stress ◽  
Shear Loading ◽  
Shear Stress Distribution ◽  
Shear Stresses ◽  
Shearing Force ◽  
Dynamic Component ◽  
Geometrical Properties

A brief note is given on various components of the longitudinal vertical shearing force. The stillwater component is examined with particular emphasis on the effect of local cargo loading and the mechanism of shear load transmission. The main factors affecting the wave-induced and dynamic components are indicated and an approximate method is given for estimating the impulsive dynamic component. A method is then given for calculating the shear stress distribution over a typical section of a bulk carrier. The ship section is idealized by a simplified structural model comprising closed and open cells. The structural model retains all the geometrical properties of the original section. Two numerical examples are considered to examine the effect of ship section parameters on shear stress distribution. It is shown that:(i) High shear stresses may be developed in the side shell plating.(ii) The variation of ship section parameters has a negligible effect on the maximum shear stress and may have a significant local effect.(iii) The shear carrying capacity of a given ship section could be easily estimated. Alternatively, for a given shearing force, a "shear coefficient," representing shear capability, could be estimated.

Extensional Effects in Constrained Viscoelastic Layer Damping

1974 ◽  
Vol 25 (3) ◽  
pp. 225-231 ◽  
Author(s):  
B C Nakra ◽  
P Grootenhuis
Keyword(s):  
Shear Stress ◽  
Stress Distribution ◽  
Loss Factor ◽  
Vibration Damping ◽  
Shear Stress Distribution ◽  
Viscoelastic Layer ◽  
Shear Stresses ◽  
Combined Effects ◽  
Resonant Modes

SummaryThe vibration damping in unsymmetrical, multi-layer beams is obtained by the combined effects of extensional and shear stresses in the viscoelastic layer. The shear stress distribution is not constant across such a layer, although previous work has ignored this. The error in an estimate based on the previous work of the overall loss factor can be large, in particular for the lower resonant modes of long beams with a stiff damping layer.

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