Application of the dividing grid method in the investigation of plastic strain within the stress concentration zone

1983 ◽  
Vol 15 (9) ◽  
pp. 1336-1340
Author(s):  
V. I. Skripchenko ◽  
A. L. Kaplinskii ◽  
V. A. Khyuvenen
Keyword(s):  
Stress Concentration ◽  
Plastic Strain ◽  
Grid Method ◽  
Stress Concentration Zone ◽  
Concentration Zone

Roadway Deformation Test for Machine Excavation Disturbance

2012 ◽  
Vol 616-618 ◽  
pp. 370-375
Author(s):  
Shan Yang Wei ◽  
Lei Wang ◽  
Teng Li ◽  
Tian Bao Gao ◽  
Ming Liu
Keyword(s):  
Stress Concentration ◽  
Stress Concentration Zone ◽  
Concentration Zone ◽  
Stable Convergence ◽  
Working Face ◽  
Deformation Amount ◽  
Wall Deformation ◽  
Deformation Test ◽  
Roadway Deformation

It can be concluded that two abreast near ways were suffered disturbed effects by one another in the cause of one’s excavation by studying the disturbed effects between JI17-22300 air way and machine way of JI16-22320 working face in the course of excavation ofJI17-22300 air way in Pingmei Shares Shikuang. We found three kinds of phenomenons. Firstly, the biggest deformation was the floor. Secondly, the stress concentration zone was10m-20m in front of the head of the roadway and floor drum violent activities for a period of 6-7 days. Lastly, stress appeared on two walls earlier of that of roof and floor stress appearance, namely wall deformation happened in distance of head-on20m, wall deformation amount begins to tend stable convergence after50~60 meters of roadway, those were happened in the roadways which were 450m depth, 11m span and at the drivage speed of 10m/d.

Thermal-Fatigue Analysis of Turbine Discs under Complex Thermo-Mechanical Loading with Account of Plasticity and Creep Effects

2015 ◽  
Vol 725-726 ◽  
pp. 955-960 ◽  
Author(s):  
Igor Ignatovich ◽  
Artem S. Semenov ◽  
Sergey Semenov ◽  
Leonid Getsov
Keyword(s):  
Stress Concentration ◽  
Strain State ◽  
Local Strain ◽  
Complex Stress ◽  
Material Behavior ◽  
Stress Concentration Zone ◽  
Concentration Zone ◽  
Stress Strain ◽  
Thermomechanical Cycling ◽  
Stress Strain State

During operation of transport and maneuverable gas-turbine units, there are crack formation in turbine disc rims what exerted by thermomechanical cycling loads. For in-depth study of these problems we have to use theories of plasticity and creep which form the basis for determining the complex stress-strain state in the stress concentration zone for disc rims, and a modern failure criterion which can predict lifetime under conditions of simultaneous plastic and creep strain accumulation. There is a finite-element method (FEM) that allows us to evaluate the stress-strain state in a stress concentration zone for a non-elastic material behavior. With plasticity and creep theories, it is possible to determine local strain quiet reliable by FEM.

scholarly journals Improvement of Gas Drainage Efficiency via Optimization of Sealing Depth of Cross-Measure Boreholes

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Pu Li ◽  
Zhiheng Cheng ◽  
Liang Chen ◽  
Hongbing Wang ◽  
Jialin Cao
Keyword(s):  
Stress Concentration ◽  
Drainage System ◽  
Stress Concentration Zone ◽  
Concentration Zone ◽  
Air Leakage ◽  
In Situ Tests ◽  
Gas Drainage ◽  
Drainage Borehole

The sealing depth of a gas-drainage borehole is critically important as it directly affects the efficiency of the whole drainage system. In order to determine the shortest reasonable sealing depth, in this paper, a theoretical drainage model using different sealing depths was proposed. Based on theoretical analysis presented, two parts of the fractures system surrounding the drainage borehole were proposed, i.e. the fractures induced by roadway excavation and the fractures induced by borehole drilling. A series of geological in-situ tests and simulations research were conducted to determine the stress and fracture distributions in the surrounding rock of the borehole. The depths of crushing zones, plastic zones and stress concentration zones were determined as 5 m, 2 m and 12 m, respectively. Meanwhile, stress simulation shows that the depth of the stress concentration zone was 12 m from the roadway wall and the stress peak was located at the depth of 8 m, which can be verified by the results of drilling penetration velocity analysis. To determine the optimum sealing depth, gas drainage holes with different sealing depths were drilled in the field. The field results revealed that the crushing zones were the main area for air leakage, and the stress concentration induced by roadway excavation assisted in the reduction of air leakage. Therefore, the optimized sealing depth should both cover the plastic zone and the stress concentration zone. The research achievements can provide a quantitative method for the determination of optimum sealing depth in cross-measure drainage boreholes.

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