Distinguishing Welding Defects from the Stress Concentration Zone Using Metal Magnetic Memory Field Parameters

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.

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Characterisation of stress concentration of ferromagnetic materials by metal magnetic memory testing

Nondestructive Testing And Evaluation ◽

10.1080/10589750902795366 ◽

2010 ◽

Vol 25 (2) ◽

pp. 145-151 ◽

Cited By ~ 14

Author(s):

Lihong Dong ◽

Binshi Xu ◽

Shiyun Dong ◽

Qunzhi Chen

Keyword(s):

Stress Concentration ◽

Ferromagnetic Materials ◽

Magnetic Memory ◽

Memory Testing ◽

Metal Magnetic Memory ◽

Metal Magnetic Memory Testing

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Eddy Current and Metal Magnetic Memory Testing Nondestructive Evaluation for Superficial Defects of Old Cylinder Barrel

Materials Science Forum ◽

10.4028/www.scientific.net/msf.850.107 ◽

2016 ◽

Vol 850 ◽

pp. 107-112

Author(s):

Chang Liang Shi ◽

Shi Yun Dong ◽

Wei Xue Tang ◽

Hao Zhan

Keyword(s):

Stress Concentration ◽

Eddy Current ◽

Eddy Current Testing ◽

Magnetic Memory ◽

Memory Testing ◽

Metal Magnetic Memory ◽

Current Testing ◽

Cylinder Barrel ◽

Metal Magnetic Memory Testing

Eddy current testing and metal magnetic memory testing, cooperated with special testing devices, were applied to detect the superficial defects of old cylinder barrel. It was indicated that there were three types of the signals, which were non-defect signals, discontinuous peak signals and continuous peak signals. Non-defect signals indicated that there was no defect in cylinder barrel, and the discontinuous peak signals denoted that there was circumferential cracking, and the continuous peak signals showed that there was longitudinal cracking in the surface of cylinder barrel. The amplitude of eddy current testing signals characterizes the depth of cracking, and the gradient of magnetic signals descript the degree of stress concentration. The method mentioned above detects the cracking and stress concentration in the superficial coat of old cylinder barrel, which effectively guarantee the quality of automobile cylinder.

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

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.725-726.955 ◽

2015 ◽

Vol 725-726 ◽

pp. 955-960 ◽

Cited By ~ 1

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.

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