The Yield of Mild Steel with Particular Reference to the Effect of Size of Specimen

1939 ◽  
Vol 142 (1) ◽  
pp. 193-223 ◽  
Author(s):  
J. L. M. Morrison
Keyword(s):  
Shear Stress ◽  
Stress Distribution ◽  
Mild Steel ◽  
Heat Treating ◽  
Uniform Stress ◽  
Tension Tests ◽  
Tension And Compression ◽  
Shear Strain Energy ◽  
Material Tests ◽  
Surface Decarburization

The paper is a description of an investigation undertaken to determine, by tests under various conditions of uniform and non-uniform stress distribution, the criterion of yield in specimens of mild steel. Apparatus is described for heat-treating the material after machining in such a manner as to avoid surface decarburization, and for determining the stresses at yield of specimens tested in tension, compression, flexure, torsion, and combined tension and torsion. The results show that the material used is uniform and isotropic. No differences are found between the yield in tension and compression. Tension tests on thin tubes and on solid specimens of varying size indicate a progressive change from single-crystal stress-strain characteristics to the normal characteristics of polycrystalline material. Tests in combined tension and torsion give results which accord with the theory of yield at a critical value of the shear strain energy stored per unit volume of the material, but this is shown to be entirely due to the size of the specimens tested. In all cases of nonuniform stress distribution, the yielding is shown to depend on the specimen size, being delayed until a shear stress not less than the shear stress at yield under uniform stress is applied to a thickness of material of the order of a few crystal diameters.

The Departure from Equilibrium of Turbulent Boundary Layers

1968 ◽  
Vol 19 (1) ◽  
pp. 1-19 ◽  
Author(s):  
H. McDonald
Keyword(s):  
Boundary Layer ◽  
Shear Stress ◽  
Kinetic Energy ◽  
Stress Distribution ◽  
Boundary Layers ◽  
Turbulent Boundary Layers ◽  
Two Dimensional ◽  
Pressure Distributions ◽  
Momentum Integral ◽  
State Examination

SummaryRecently two authors, Nash and Goldberg, have suggested, intuitively, that the rate at which the shear stress distribution in an incompressible, two-dimensional, turbulent boundary layer would return to its equilibrium value is directly proportional to the extent of the departure from the equilibrium state. Examination of the behaviour of the integral properties of the boundary layer supports this hypothesis. In the present paper a relationship similar to the suggestion of Nash and Goldberg is derived from the local balance of the kinetic energy of the turbulence. Coupling this simple derived relationship to the boundary layer momentum and moment-of-momentum integral equations results in quite accurate predictions of the behaviour of non-equilibrium turbulent boundary layers in arbitrary adverse (given) pressure distributions.

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 Design of plate and screw anchors in dense sand: failure mechanism, capacity and deformation

2019 ◽  
Vol 92 ◽  
pp. 16010
Author(s):  
Benjamin Cerfontaine ◽  
Jonathan Knappett ◽  
Michael Brown ◽  
Aaron Bradshaw
Keyword(s):  
Shear Stress ◽  
Stress Distribution ◽  
Failure Mechanism ◽  
Progressive Failure ◽  
Vertical Direction ◽  
Shear Plane ◽  
Design Methods ◽  
Embedment Depth ◽  
Limiting State ◽  
Dense Sand

Plate and screw anchors provide a significant uplift capacity and have multiple applications in both onshore and offshore geotechnical engineering. Uplift design methods are mostly based on semi-empirical approaches assuming a failure mechanism, a normal and a shear stress distribution at failure and empirical factors back-calculated against experimental data. However, these design methods are shown to under- or overpredict most of the existing larger scale experimental tests. Numerical FE simulations are undertaken to provide new insight into the failure mechanism and stress distribution which should be considered in anchor design in dense sand. Results show that a conical shallow wedge whose inclination to the vertical direction is equal to the dilation angle is a good approximation of the failure mechanism in sand. This shallow mechanism has been observed in each case for relative embedment ratios (depth/diameter) ranging from 1 to 9. However, the stress distribution varies non-linearly with depth, due to the soil deformability and progressive failure. A sharp peak of normal and shear stress can be identified close to the anchor edge, before a gradual decrease with increasing distance along the shear plane. The peak stress magnitude increases almost linearly with embedment depth at larger relative embedment ratios. Although further research is necessary, these results lay the basis for the development of a new generation of design criteria for determining anchor capacity at the ultimate limiting state.

Plastic Analysis of Metal Sheet Forming with SD Effects

2013 ◽  
Vol 299 ◽  
pp. 216-220
Author(s):  
Zhen Yu Chen ◽  
Chun Du Wu ◽  
Zhong Xian Wang
Keyword(s):  
Shear Stress ◽  
Yield Criterion ◽  
High Strength ◽  
Sheet Forming ◽  
Metal Sheet ◽  
Film Stress ◽  
Strength Differential ◽  
Thin Film Stress ◽  
Plastic Analysis ◽  
Tension And Compression

Generally, many high-strength alloy materials used in aerospace, power and chemical industries have strength differential effect in tension and compression (SD effects). Usually, in mechanical calculations of sheet metal forming, Treasca yield criterion and Mises yield criterion are applied. Because the yield criterions don’t take SD effects into consideration, the calculation result may have errors for certain materials. However, generalized twin shear stress yield criterion, which takes into account the influence of the intermediate principal stress, is more suitable for most metal materials than Mohr-Coulomb strength theory. Therefore, this article has made plastic analysis on thin film stress issues of metal sheet forming with generalized twin shear stress yield criterion. We have obtained a unified plastic solution to the internal and external stretching issue of thin material with rounded holes and different tension and compression ratio. Providing a new result with wider applicability is very significant.

scholarly journals Wall Shear Stress Distribution of Small Aneurysms Prone to Rupture

Stroke ◽  
2014 ◽  
Vol 45 (1) ◽  
pp. 261-264 ◽  
Author(s):  
Vitor Mendes Pereira ◽  
Olivier Brina ◽  
Philippe Bijlenga ◽  
Pierre Bouillot ◽  
Ana Paula Narata ◽  
...  
Keyword(s):  
Shear Stress ◽  
Stress Distribution ◽  
Wall Shear Stress ◽  
Shear Stress Distribution ◽  
Wall Shear Stress Distribution ◽  
Wall Shear ◽  
Small Aneurysms
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