scholarly journals Numerical Simulation on the Effect of Rock Joint Roughness on the Stress Field

2022 ◽  
Vol 2148 (1) ◽  
pp. 012025
Author(s):  
J Wang ◽  
J Liu ◽  
Y Q Fu
Keyword(s):  
Numerical Simulation ◽  
Shear Stress ◽  
Stress Concentration ◽  
Stress Field ◽  
Compression Test ◽  
Maximum Shear Stress ◽  
Normal Pressure ◽  
Joint Roughness ◽  
Axial Shear ◽  
Joint Plane

Abstract In view of the influence of Joint Roughness Coefficient (JRC), which is for quantitative description of the joint surface roughness, on the stress field of the rock mass, compression test and shear-compression test were simulated on models with different joint roughness. The photoelasticity technique is applied to examine the feasibility of numerical simulation. The results show that numerical simulation results are in agreement with the results of photoelastic experiments. The stress concentration area is distributed near the joint plane. Thus, the joint plane controls the shear strength of the rock. In compression test, the maximum shear stress of the model is proportional to JRC and the normal pressure. In shear-compression test, when the ratio of the axial shear to the normal pressure is small, the maximum shear stress is nonlinearly positively correlated with JRC. When the ratio of the axial shear to the normal pressure is relatively large, the relationship curve between the maximum shear stress and JRC is parabolic. When the JRC is small, as the ratio of the axial shear force to the normal pressure increases, the maximum shear stress changes abruptly, and the maximum shear stress after the mutation decreases significantly. The reason is that the upper and lower parts of the model have slipped, resulting in a redistribution of stress. In addition, when the JRC is 6 to 12, it is more likely to cause stress concentration.

Numerical Simulation of the Stress Field of Thick 7B04 Aluminum Alloy Board during Continuous Manufacture Procedure

2007 ◽  
Vol 127 ◽  
pp. 259-264
Author(s):  
Hong Yuan Fang ◽  
Cheng Iei Fan
Keyword(s):  
Numerical Simulation ◽  
Aluminum Alloy ◽  
Stress Concentration ◽  
Stress Field ◽  
Solution Treatment ◽  
Simulation Method ◽  
The Core ◽  
Manufacturing Procedure ◽  
Continuous Manufacture ◽  
Simulation Results

Numerical simulation method is employed in the article to analyze the stress field of thick 7B04 aluminum alloy board during manufacturing procedure of solution treatment, calendaring and stretching. The simulation results show that the surface of the board endures compressive stress while the core segment endures tensile stress, and the distribution of the stress is very inhomogeneous. The calendaring procedure helps to decrease the stress and redistribute the stress uniformly, but it also leads to stress concentration at the two ends of the board, which engenders bad influence on the subsequent processing. The board deforms plastically when being stretched, thus the stress decreases greatly and is redistributed uniformly.

scholarly journals Iosipescu Shear Test of Composite Joint Specimens in Tensile Loading

1995 ◽  
Vol 4 (4) ◽  
pp. 096369359500400 ◽  
Author(s):  
Jang-Kyo Kim ◽  
Joo Hyuk Park
Keyword(s):  
Shear Stress ◽  
Stress Field ◽  
Composite Laminates ◽  
Shear Test ◽  
Pure Shear ◽  
Maximum Shear Stress ◽  
Tensile Loading ◽  
Composite Joint ◽  
Loading Method ◽  
Iosipescu Shear Test

The stress field arising in tensile loading of the Iosipescu shear test is analyzed by means of finite element method. In a parametric study on a composite laminates-adhesive joint, the tensile loading method is shown more effective in creating a pure shear stress field with negligible normal stresses in the notched area than the conventional compressive loading method, although the maximum shear stress is marginally higher for the former method than the latter.

Internal Stresses in Elastohydrodynamic Lubrication of Rolling/Sliding Contacts

1989 ◽  
Vol 111 (1) ◽  
pp. 180-187 ◽  
Author(s):  
Farshid Sadeghi ◽  
Ping C. Sui
Keyword(s):  
Shear Stress ◽  
Stress Distribution ◽  
Internal Stress ◽  
Maximum Shear Stress ◽  
Elastohydrodynamic Lubrication ◽  
Normal Pressure ◽  
Internal Stresses ◽  
Stress Distributions ◽  
Principal Stresses ◽  
Dimensionless Velocity

The internal stress distribution in elastohydrodynamic lubrication of rolling/sliding line contact was obtained. The technique involves the full EHD solution and the use of Lagrangian quadrature to obtain the internal stress distributions in the x, y, z-directions and the shear stress distribution as a function of the normal pressure and the friction force. The principal stresses and the maximum shear stress were calculated for dimensionless loads ranging from (2.0452 × 10−5) to (1.3 × 10−4) and dimensionless velocity of 10−10 to 10−11 for slip ratios ranging from 0 to pure sliding condition.

The Influence of the Coefficient of Friction on the Elastic Stress Concentration Factor for a Pin-Jointed Connection

1962 ◽  
Vol 13 (1) ◽  
pp. 17-29 ◽  
Author(s):  
T. H. Lambert ◽  
R. J. Brailey
Keyword(s):  
Shear Stress ◽  
Stress Concentration ◽  
Coefficient Of Friction ◽  
Stress Concentration Factor ◽  
Elastic Stress ◽  
Maximum Shear Stress ◽  
Interference Fit ◽  
Stress Load ◽  
The Coefficient Of Friction ◽  
Very High

SummaryThe benefit to be obtained by using an interference fit between the pin and plate in a pin-jointed connection has already been established. An examination of the published results shows that some non-linearity occurs in the mechanism of load transference from the pin to the plate since, except at very high initial interference, doubling the load on the joint more than doubles the maximum shear stress in the plate. An examination of the stress-load relationship shows a distinct discontinuity, the load at which this discontinuity occurs being dependent upon both the initial interference and the coefficient of friction between the pin and the plate. It is shown that the results hitherto published correspond to a coefficient of friction between the pin and the plate of 0.3 and results for lower and higher coefficients are given.

Numerical Simulation of Flow Field Dynamics Characteristics for One Novel Twin-Screw Kneader

2012 ◽  
Vol 271-272 ◽  
pp. 1049-1055
Author(s):  
Jing Wei ◽  
Xin Long Liang ◽  
Wei Sun ◽  
Li Cun Wang
Keyword(s):  
Numerical Simulation ◽  
Shear Stress ◽  
Flow Field ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Maximum Shear Stress ◽  
Twin Screw ◽  
Screw Rotors ◽  
Center Distance

The numerical simulation for dynamic characteristics of the flow field of a novel twin-screw kneader is carried out. The flow field model of the twin-screw kneader is established, and the three-dimensional, isothermal and steady numerical analysis of non-Newtonian fluid is presented based on computational fluid dynamics (CFD) theory, and the characteristics under the conditions of different speeds and center distances such as the distribution of pressure and velocity field, the maximum shear stress, the mass flow rate and so on, are studied. The research results show that: with increasing speed, the maximum flow pressure, the mass flow rate, the maximum shear stress will increase; the maximum shear stress increases first and then decreases with increasing of center distance of the screw rotors, while the mass flow rate increases with increasing of center distance; but when the center distance reaches a certain degree, the mass flow rate will be negative and the material will appear serious reflux which can lead the kneader to stopping working.

Stress analysis of some nut-bolt connections with modifications to the external shape of the nut

1987 ◽  
Vol 22 (4) ◽  
pp. 187-193 ◽  
Author(s):  
E A Patterson ◽  
B Kenny
Keyword(s):  
Shear Stress ◽  
Stress Concentration ◽  
Outer Surface ◽  
Maximum Stress ◽  
Maximum Shear Stress ◽  
Three Dimensional ◽  
Fatigue Tests ◽  
Steel Connections ◽  
Circumferential Groove ◽  
Stress Study

The effect on the stress levels in an axially loaded bolt has been investigated for the case where a nut which incorporated a circumferential groove in its outer surface was used. It was found from a three-dimensional photoelastic frozen stress study that the modified nut reduced the maximum stress in the bolt by 5 per cent. The addition of a bevel to the load bearing face of this nut further reduced the maximum stress to 74 per cent of its value in a standard connection. It has been established that these modifications reduce the maximum shear stress in the roots of the nut threads, and that the stress concentration associated with the groove was smaller than the maximum stress concentration in both the nut and bolt thread roots. The increase indicated by photoelastic analyses in the strength of the connection produced by these modifications, has also been substantiated by fatigue tests of steel connections, but these results are not reported in this paper.

Asymptotic Stress Fields for Stationary Cracks Along the Gradient in Functionally Graded Materials

2002 ◽  
Vol 69 (3) ◽  
pp. 240-243 ◽  
Author(s):  
V. Parameswaran ◽  
A. Shukla
Keyword(s):  
Shear Stress ◽  
Stress Field ◽  
Functionally Graded Materials ◽  
Maximum Shear Stress ◽  
Functionally Graded ◽  
Stress Fields ◽  
Shear Mode ◽  
Graded Materials ◽  
Opening Mode ◽  
Constant Maximum

Stress field for stationary cracks, aligned along the gradient, in functionally graded materials is obtained through an asymptotic analysis coupled with Westergaard’s stress function approach. The first six terms of the stress field are obtained for both opening mode and shear mode loading. It is observed that the structure of the terms other than r−1/2 and r0 are influenced by the nonhomogeneity. Using this stress field, contours of constant maximum shear stress are generated and the effect of nonhomogeneity on these contours is discussed.

PHOTOELASTIC STUDY ON THE MECHANICAL PROPERTIES OF FRACTAL ROCK JOINTS

Fractals ◽  
1996 ◽  
Vol 04 (04) ◽  
pp. 521-531 ◽  
Author(s):  
HEPING XIE ◽  
WEIHONG XIE ◽  
PENG ZHAO
Keyword(s):  
Mechanical Properties ◽  
Shear Stress ◽  
Shear Strength ◽  
Fractal Dimension ◽  
Maximum Shear Stress ◽  
Fractal Dimensions ◽  
Rock Joints ◽  
Peak Shear Strength ◽  
Joint Roughness ◽  
Contact Points

In this paper, the fractal rock joints are manufactured on the photoelastic material plate. Based on the visualized photoelastic experiments, the mechanical properties of the fractal joints with different roughness (different fractal dimensions) are investigated under uniaxial and shear compression. The research results indicate that the joint roughness (the fractal dimension of the joints) significantly influences the peak shear strength, the position of the maximum shear stress, and the number of contact points.

scholarly journals Slope stability monitoring from microseismic field using polarization methodology

2003 ◽  
Vol 3 (6) ◽  
pp. 515-521 ◽  
Author(s):  
Yu. I. Kolesnikov ◽  
M. M. Nemirovich-Danchenko ◽  
S. V. Goldin ◽  
V. S. Seleznev
Keyword(s):  
Numerical Simulation ◽  
Shear Stress ◽  
Stress Concentration ◽  
Slope Stability ◽  
Tien Shan ◽  
Polarization Analysis ◽  
Horizontal Polarization ◽  
Stability Monitoring ◽  
Landslide Slope ◽  
Northern Tien Shan

Abstract. Numerical simulation of seismoacoustic emission (SAE) associated with fracturing in zones of shear stress concentration shows that SAE signals are polarized along the stress direction. The proposed polarization methodology for monitoring of slope stability makes use of three-component recording of the microseismic field on a slope in order to pick the signals of slope processes by filtering and polarization analysis. Slope activity is indicated by rather strong roughly horizontal polarization of the respective portion of the field in the direction of slope dip. The methodology was tested in microseismic observations on a landslide slope in the Northern Tien-Shan (Kyrgyzstan).

Numerical Simulation and Analysis of Interior Shear Stress in Centrifugal Cardio Pump

2013 ◽  
Vol 732-733 ◽  
pp. 426-431
Author(s):  
Xue Bing Dai ◽  
Jian Pu Xu ◽  
Liang Zhang
Keyword(s):  
Numerical Simulation ◽  
Shear Stress ◽  
Stress Distribution ◽  
Geometric Modeling ◽  
Optimization Design ◽  
Maximum Shear Stress ◽  
Critical Shear Stress ◽  
Flow Distribution ◽  
Shear Stress Distribution ◽  
Recirculation Region

Two centrifugal cardio pumps with recirculation region and anti-recirculation region are designed by speed coefficient method. We can obtain the flow distribution of impeller and inside the shell at design conditions from geometric modeling and numerical simulation of two cardio pumps by using related software, and compared the interior shear stress distribution of two cardio pumps at the same condition. The results show that the maximum shear stress in the cardio pump with the recirculation region is lower about 10% than the pump with the anti-recirculation region and the region of the shear stress is exceed the critical shear stress (150Pa) which produced hemolytic is less about 2/3 than the cardio pump with the anti-recirculation region from the shear stress distribution. As a result a tiny destroys are caused to the blood cell and the pump with the anti-recirculation region model correspond with the demand of the haemophysiology, the research results provide the theory reference and basis in the optimization design for such artificial cardio pump.

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