Optimum Design of Ribbon and Wire Wound Cylinders for Metal Forming Dies

1977 ◽  
Vol 99 (3) ◽  
pp. 733-737 ◽  
Author(s):  
J. Gro̸nbaek ◽  
T. Wanheim
Keyword(s):  
Shear Stress ◽  
Stress Distribution ◽  
Tensile Stress ◽  
Optimum Design ◽  
Metal Forming ◽  
Working Pressure ◽  
Internal Working ◽  
Shrink Fit

The ribbon winding process enables the manufacture of metal forming dies with higher allowable internal working pressure than is possible by conventional shrink-fit constructions. Varying the tensile stress in the ribbon in the winding process, the stress distribution in the die can be given a predetermined shape. Based on the assumption that all ribbon layers carry the same shear stress when the internal working pressure is acting, a new winding theory is derived. This method permits the internal working pressure to be increased about 30 percent compared to that of the previously known winding theories and about 60 percent compared to that of shrink-fit constructions.

AN ANALYTICAL SOLUTION FOR OPTIMUM DESIGN OF SHRINK-FIT MULTI-LAYER COMPOUND CYLINDERS

2012 ◽  
Vol 04 (04) ◽  
pp. 1250043 ◽  
Author(s):  
M. SHARIFI ◽  
J. ARGHAVANI ◽  
M. R. HEMATIYAN
Keyword(s):  
Shear Stress ◽  
Optimum Design ◽  
Maximum Shear Stress ◽  
Layer Compound ◽  
Compound Cylinder ◽  
Number Of Layers ◽  
Shrink Fitting ◽  
Tresca Criterion ◽  
Analytical Relations ◽  
Shrink Fit

In this paper, employing an analytical method, optimum design of multi-layer compound cylinders is investigated. To this end, considering Tresca criterion, maximum shear stress in each layer is minimized. Analytical relations for optimum values of a layer dimension, residual pressures and radial interferences are derived. A technique for shrink-fitting of layers is also proposed and relationships for radial interferences, residual pressures and required temperature differences during the shrink-fitting process are derived. Three different examples are presented to show the effectiveness of the proposed method. It is shown that increasing the number of layers makes shear stress distribution near to uniform. As a result, with specified maximum shear stress and inner radius, the weight of compound cylinder is decreased when the number of layers is increased. Moreover, compound cylinders with more layers have lower maximum shear stress for a specified weight. It is also concluded that if the ratio of outer to inner radii be larger, increasing the number of layers is more effective.

A New Approach for Bearing Capacity of SRC Columns with Bond Failure

2010 ◽  
Vol 163-167 ◽  
pp. 1157-1161
Author(s):  
Kai Wu ◽  
Jian Yang Xue ◽  
Ping Zhou Cao ◽  
Hong Tie Zhao ◽  
Jian Guang Yue
Keyword(s):  
Shear Stress ◽  
Stress Distribution ◽  
Tensile Stress ◽  
Bearing Capacity ◽  
Final Stage ◽  
Bond Failure ◽  
Rectangular Section ◽  
New Approach ◽  
Shear Model ◽  
Formula Derivation

Bond stress between concrete and shape steel makes both materials cooperate as a whole, but diminished at final stage of loading period. A shear model is established to throw illumination on mechanism of bond failure. Tensile stress in concrete leaded to bond cracks and eventually the bond failure, which is due to the shear passing from concrete to shape steel. A new approach for bearing capacity of SRC columns with bond failure is put forward which based on the equivalent law of shear stress and shear stress distribution of rectangular section for formula derivation, the calculated results are consistent with those of the test.

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.

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