An Application of the Maximum Shear Strain Increment in Searching Sliding Surfaces

2013 ◽  
Vol 423-426 ◽  
pp. 1618-1622 ◽  
Author(s):  
Liu Yong Cheng ◽  
Jian Li ◽  
Shan Xiong Chen ◽  
Xiao Jie Chu
Keyword(s):  
Shear Strain ◽  
Least Squares Method ◽  
Limit Equilibrium ◽  
Quadratic Function ◽  
Strain Increment ◽  
Vertical Line ◽  
Sliding Surface ◽  
Maximum Shear Strain ◽  
Sliding Surfaces ◽  
Different Depths

A slope landslides generally at the place where the shear strain increment is the largest. This position is considered as the standard of defining sliding surfaces to assess the slope stability under the action of the foundation. A new method is proposed to determine the potential sliding surface, which is based on the largest shear strain increment. Firstly, the stress and strain in the slope were calculated by using the finite difference software-FALC3D. Secondly, a series of vertical line would be set in the calculating section. And then the discrete coordinates of the sliding surface, where the shear strain is largest on the vertical line, would be found through programming fish program. At last the position and shape of the sliding surface can be obtained through carrying on curve fitting of the discrete points by using the least squares method. The concept of this method is clear and can reflect the true form of the sliding surface through contrasting with the limit equilibrium method. Sliding surfaces of different depths and distances of slope are researched and a quadratic function is put forward which can describe the trends of glide direction. Three coefficients of the quadratic function were analyzed and the corresponding expression was obtained which can provide a reference to specification revision and engineering.

scholarly journals Method and Mechanism of Dump Overlying the Bedrock with Large Dip Angle in Opencast Mine

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Hongze Zhao ◽  
Hairui Du ◽  
Zhigang Tao ◽  
Zechen Lin
Keyword(s):  
Shear Strain ◽  
Limit Equilibrium ◽  
Quadratic Function ◽  
Strain Increment ◽  
Open Pit ◽  
Stability Factor ◽  
Deformation And Failure ◽  
Dispersion Degree ◽  
Dip Angle ◽  
The Stability

Dump in the steep area of the open-pit mine is essential for safe production. The bedrock with the bumpy-surface blasting method effectively improves the stabilization of the dumpsite. The effect of the ratio and dispersion degree on the deformation and failure of the dumping bench at the largely inclined area was analyzed. Based on the limit equilibrium method, the equation about the stability factor and the blasted region ratio was deduced. Virtual experiments were performed to address how the ratio and dispersion degree affect deformation and failure. The results showed that the stability factor is a quadratic function of the ratio of the blasted area. The increase in the ratio results in a drastic reduction of displacement, and the direction of displacement significantly changes. The rise in the dispersion degree effectively reduces the displacement and shear strain increment, and the failure mode changes. There is a specific value for the ratio and dispersion degree, making the displacement and shear strain increment little. The research on bumpy surface blasting in this paper provides the theoretical foundation for the dump construction at the site with the large dip angle.

Interaction of tungsten in dry sliding against steel under high density electric current

2019 ◽  
pp. 101-109 ◽  
Author(s):  
M. I. Aleutdinova ◽  
V. V. Fadin ◽  
Yu. P. Mironov
Keyword(s):  
Electrical Contact ◽  
Analysis Data ◽  
Dry Sliding ◽  
Sliding Surface ◽  
X Ray ◽  
Sliding Surfaces ◽  
Quenched Steel ◽  
Sliding Electrical Contact ◽  
A Current ◽  
Tungsten Steel

The possibility of creating a wear-resistant dry sliding electrical contact tungsten/steel was studied. It was shown that tungsten caused severe wear of the quenched steel counterbody due to unlimited plastic flow of its surface layer at a current density up to 150 A/cm2 . This indicated the impossibility of achieving satisfactory characteristics of such a contact. Low electrical conductivity and wear resistance of the contact tungsten/steel were presented in comparison with the known high copper/steel contact characteristics under the same conditions. X-ray phase analysis data of the steel sliding surfaces made it possible to state that the cause of the unsatisfactory sliding of tungsten was the absence of the necessary concentration of FeO oxide on the sliding surface of the steel. 

Robust sliding mode control for a class of underactuated systems with mismatched uncertainties

2009 ◽  
Vol 223 (6) ◽  
pp. 785-795 ◽  
Author(s):  
D W Qian ◽  
X J Liu ◽  
J Q Yi
Keyword(s):  
Robust Control ◽  
Sliding Mode Control ◽  
Control Method ◽  
Sliding Mode ◽  
Underactuated Systems ◽  
Sliding Surface ◽  
Nominal System ◽  
Sliding Surfaces ◽  
Mode Control ◽  
Mismatched Uncertainties

Based on the sliding mode control methodology, this paper presents a robust control strategy for underactuated systems with mismatched uncertainties. The system consists of a nominal system and the mismatched uncertainties. Since the nominal system can be considered to be made up of several subsystems, a hierarchical structure for the sliding surfaces is designed. This is achieved by taking the sliding surface of one of the subsystems as the first-layer sliding surface and using this sliding surface and the sliding surface of another subsystem to construct the second-layer sliding surface. This process continues till the sliding surfaces of all the subsystems are included. A lumped sliding mode compensator is designed at the last-layer sliding surface. The asymptotic stability of all of the layer sliding surfaces and the sliding surface of each subsystem is proven. Simulation results show the validity of this robust control method through stabilization control of a system consisting of two inverted pendulums and mismatched uncertainties.

Slope Stability Analysis of Elastic Limit Equilibrium Method

2013 ◽  
Vol 275-277 ◽  
pp. 1423-1426
Author(s):  
Lin Kuang ◽  
Ai Zhong Lv ◽  
Yu Zhou
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Safety Factor ◽  
Slip Surface ◽  
Limit Equilibrium ◽  
Limit Equilibrium Method ◽  
Slope Stability Analysis ◽  
Sliding Surface ◽  
Tangential Stresses ◽  
Equilibrium Method

Based on finite element analysis software ANSYS, slope stability analysis is carried out by Elastic limiting equilibrium method proposed in this paper. A series of sliding surface of the slope can be assumed firstly, and then stress field along the sliding surface is analyzed as the slope is in elastic state. The normal and tangential stresses along each sliding surface can be obtained, respectively. Then the safety factor for each slip surface can be calculated, the slip surface which the safety factor is smallest is the most dangerous sliding surface. This method is different from the previous limit equilibrium method. For the previous limit equilibrium method, the normal and tangential stresses along the sliding surface are calculated based on many assumptions. While, the limit equilibrium method proposed in this paper has fewer assumptions and clear physical meaning.

Study on Thermal Cycling of Sn0.7Cu Solder

2013 ◽  
Vol 791-793 ◽  
pp. 362-365
Author(s):  
Li Yang ◽  
Ju Li Li ◽  
Jing Guo Ge ◽  
Meng Li ◽  
Nan Ji
Keyword(s):  
Shear Stress ◽  
Steady State ◽  
High Temperature ◽  
Thermal Cycling ◽  
Shear Strain ◽  
Maximum Shear Stress ◽  
Steady State Creep ◽  
Maximum Shear Strain ◽  
Cycle Number ◽  
State Cycle

Thermal cycling of a unit Sn0.7Cu solder was studied based on the steady-state creep constitutive equation and Matlab software. The results show that there is a steady-state cycle for the thermal cycling of unit Sn0.7Cu eutectic solder. In steady-state thermal cycling, the shear stress is increased with the increase of temperature. There is a stage of stress relaxation during high temperature. A liner relationship between maximum shear stress and maximum shear strain is observed during thermal cycling. The metastable cycle number is declined greatly with the increase of maximum shear strain.

scholarly journals Research on the Tunnel Excavated In Urumqi Glacier No. 1, Tianshan Glaciological Station, China

1987 ◽  
Vol 33 (113) ◽  
pp. 99-104 ◽  
Author(s):  
Huang Maohuan ◽  
Wang Zhongxiang
Keyword(s):  
Melting Point ◽  
Shear Strain ◽  
Maximum Shear Strain ◽  
Ice Surface ◽  
Basal Sliding ◽  
Glacier Ice ◽  
Glacier Motion

AbstractA tunnel was excavated in Urumqi Glacier No. 1, at the Tianshan Glaciological Station. Ice temperature, ice displacement, deformation, and basal sliding, etc. were observed at regular intervals. It is shown that the temperature near the glacier bed is close to the melting point and that the largest proportion of the overall glacier motion is within the lowermost ice layers. The glacier ice is in a state of compression. The maximum shear strain increases towards the entrance of the tunnel, corresponding to the change in slope of the ice surface, and also towards the bedrock.

Seismic Coefficients for Simplified Deepwater Slope Stability Assessment Under Earthquake Loading

2021 ◽  
Author(s):  
Aurelian C. Trandafir
Keyword(s):  
Finite Element ◽  
Slope Stability ◽  
Shear Strain ◽  
Limit Equilibrium ◽  
Slope Instability ◽  
Earthquake Loading ◽  
Complex Deformation ◽  
Correlation Relationship ◽  
Stability Analyses ◽  
Seismic Coefficient

Abstract Pseudostatic limit-equilibrium based slope stability analyses are carried out on a routine basis to evaluate stability of submarine slopes under earthquake loading. For slopes in deepwater settings, a major challenge in performing pseudostatic slope stability analyses is selection of an appropriate seismic coefficient. Most published displacement-based methodologies for seismic coefficient selection were developed using simplified sliding block models for seismic slope performance evaluation that are unable to capture the complex deformation mechanism of deepwater slopes during earthquakes. To address this challenge, this study employs two-dimensional dynamic finite-element based deformation analysis to investigate the earthquake response of submarine clay slopes characterized by morphology, stratigraphic architecture and geotechnical properties representative for the deepwater environment. Finite-element computed seismic slope performance indicators, including horizontal peak ground acceleration at the seafloor and earthquake-induced maximum shear strain within the slope, along with horizontal seismic coefficients required to trigger slope instability in limit-equilibrium based pseudostatic stability analyses are used to develop a rational shear strain-based correlation relationship for deepwater slope seismic coefficient selection.

scholarly journals The theory of plane plastic strain for anisotropic metals

1949 ◽  
Vol 198 (1054) ◽  
pp. 428-437 ◽  
Keyword(s):  
Plastic Strain ◽  
Strain Rate ◽  
Shear Strain ◽  
Plane Strain ◽  
Yield Criterion ◽  
Elliptic Functions ◽  
Shear Strain Rate ◽  
Maximum Shear Strain ◽  
Geometrical Properties ◽  
Plane Plastic

A yield criterion and plastic stress-strain relations are formulated for anisotropic metals deformed under conditions of plane strain. The equations are shown to be hyperbolic, the characteristics coinciding with the directions of maximum shear strain-rate. When the anisotropy is uniformly distributed, the variation of the stresses along the characteristics is expressed in terms of elliptic functions, and geometrical properties of the field of characteristics are established. The theory is applied to the problem of indentation by a flat die.

Longitudinal movements and resulting shear strain of the arterial wall

2006 ◽  
Vol 291 (1) ◽  
pp. H394-H402 ◽  
Author(s):  
Magnus Cinthio ◽  
Åsa Rydén Ahlgren ◽  
Jonas Bergkvist ◽  
Tomas Jansson ◽  
Hans W. Persson ◽  
...  
Keyword(s):  
Blood Flow ◽  
Shear Strain ◽  
Arterial Wall ◽  
Ultrasonic Method ◽  
Vascular Diseases ◽  
Maximum Shear Strain ◽  
Healthy Humans ◽  
New Information ◽  
Early Systole ◽  
Diameter Change

There has been little interest in the longitudinal movement of the arterial wall. It has been assumed that this movement is negligible compared with the diameter change. Using a new high-resolution noninvasive ultrasonic method, we measured longitudinal movements and diameter change of the common carotid artery of 10 healthy humans. During the cardiac cycle, a distinct bidirectional longitudinal movement of the intima-media complex could be observed in all the subjects. An antegrade longitudinal movement, i.e., in the direction of blood flow, in early systole [0.39 mm (SD 0.26)] was followed by a retrograde longitudinal movement, i.e., in the direction opposite blood flow [−0.52 mm (SD 0.27)], later in systole and a second antegrade longitudinal movement [0.41 mm (SD 0.33)] in diastole. The corresponding diameter change was 0.65 mm (SD 0.19). The adventitial region showed the same basic pattern of longitudinal movement; however, the magnitude of the movements was smaller than that of the intima-media complex, thereby introducing shear strain and, thus, shear stress within the wall [maximum shear strain between the intima-media complex and the adventitial region was 0.36 rad (SD 0.26). These phenomena have not previously been described. Measurements were also performed on the abdominal aorta ( n = 3) and brachial ( n = 3) and popliteal ( n = 3) arteries. Our new information seems to be of fundamental importance for further study and evaluation of vascular biology and hemodynamics and, thus, for study of atherosclerosis and vascular diseases.

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