scholarly journals Residual Stress Measurement of Shot-Peened Steel Rings by Barkhausen Noise, ESPI Hole-Drilling and X-Ray Diffraction

2014 ◽  
Vol 996 ◽  
pp. 380-385 ◽  
Author(s):  
Theo J. Rickert ◽  
James J. Thomas ◽  
Lasse Suominen
Keyword(s):  
Stress Measurement ◽  
Nondestructive Method ◽  
Fatigue Properties ◽  
Hole Drilling ◽  
Barkhausen Noise ◽  
Surface Zone ◽  
Near Surface ◽  
Generate Surface ◽  
Noise Measurements ◽  
Quantitative Stress

Shot-Peening is used to generate surface-near compressive residual stresses in final shape parts, usually to improve their fatigue properties. The success of the process can be checked in different ways. XRD and Hole-Drilling determine quantitative stress depth profiles in specific locations. Barkhausen noise measurements evaluate a near-surface zone in real-time and can cover large areas quickly. It is a fully nondestructive method. This study compares ESPI Hole-Drilling, which is a very fast technique, and XRD, which is very precise but slower, to Barkhausen Noise results for the case of three steel rings shot-peened with different intensities.

Measurement of Residual Stresses within a PWR Swaged Heater Tube

2011 ◽  
Vol 70 ◽  
pp. 279-284 ◽  
Author(s):  
D.M. Goudar ◽  
Ed J. Kingston ◽  
Mike C. Smith ◽  
Sayeed Hossain
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Stress Measurement ◽  
Measurement Techniques ◽  
Residual Stress Distribution ◽  
Hole Drilling ◽  
Shear Stresses ◽  
Outer Diameter ◽  
Near Surface ◽  
Heater Tube

Frequent failures of the pressuriser heater tubes used in Pressurised Water Reactors (PWRs) have been found. Axial cracks initiating from the tube outer diameter have been detected in some tubes as well as the resulting electrical problems. Replacement of the heater tubes requires an undesirably prolonged plant shutdown. In order to better understand these failures a series of residual stress measurements were carried out to obtain the near surface and through-thickness residual stress profiles in a stainless steel pressuriser heater tube. Three different residual stress measurement techniques were employed namely, Deep-Hole Drilling (DHD), Incremental Centre Hole Drilling (ICHD) and Sachs’ Boring (SB) to measure the through thickness residual stress distribution in the heater tubes. Results showed that the hoop stresses measured using all three techniques were predominantly tensile at all locations, while the axial stresses were found to be tensile at the surface and both tensile and compressive as they reduce to small magnitudes within the tube. The magnitude of the in-plane shear stresses was small at all measurement depths at all locations. The various measurement methods were found to complement each other well. All the measurements revealed a characteristic profile for the through-thickness residual stress distribution.

Residual Stress Measurement, Finite Element Mapping and Flaw Simulation for a Girth Welded Pipe

2015 ◽  
Author(s):  
Xavier Ficquet ◽  
Karim Serasli ◽  
Ed J. Kingston
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Structural Integrity ◽  
Oil And Gas ◽  
Stress Measurement ◽  
Hole Drilling ◽  
Fe Model ◽  
Mapping Procedure ◽  
Near Surface ◽  
Welded Pipe

Optimising the structural integrity of an oil and gas pipeline is hugely important for its productivity and hence profitability. The structural integrity of a pipeline is influenced by factors such as: stress (i.e. applied and residual), material properties, environment, and the size and orientation of contained flaws. For example, whilst in operation, the integrity of a pipeline can be extended by reducing its applied stresses e.g. the flow and pressure of the oil and gas running within. Prior to operation however the integrity of the pipeline can easily be extended by reducing the residual stresses generated during installation or even “negatively pre-loading” the pipeline using residual stresses to help cancel out some of the applied stresses. Therefore understanding the distribution of residual stresses within a pipeline can be of great benefit to Oil and Gas engineers. In this paper, complementary residual stress measurement techniques are used to obtain near surface and through-thickness residual stress distributions in a fully circumferential butt welded pipe. The deep hole drilling (DHD) method was used to obtain the axial and hoop residual stresses along radial lines through the pipe wall. Near surface measurements on the outer surface of the pipe were obtained using the incremental centre-hole drilling (ICHD) method. The measurements were made only at limited points in and adjacent to the circumferential weld. In order to estimate the complete residual stress field present in the pipe, a mapping procedure utilising a finite element (FE) method was implemented. This entailed introducing the measured residual stresses into a FE model of the pipe as an initial condition and allowing redistribution. Naturally, the stresses at the measurement locations should remain at their initial values. Consequently, the method was developed to allow redistribution while retaining the measured values. The paper provides these estimates of the full residual stress state present in the pipe based on this mapping procedure. The FE model was then used to simulate the influence of various sizes of flaw on the mapped residual stresses field. An assessment of the acceptability of areas of loss of the wall thickness in internally pressurised pressure vessels was then performed.

DISPERSION IN SEISMIC SURFACE WAVES

Geophysics ◽  
1951 ◽  
Vol 16 (1) ◽  
pp. 63-80 ◽  
Author(s):  
Milton B. Dobrin
Keyword(s):  
Surface Waves ◽  
Water Waves ◽  
Seismic Refraction ◽  
Wave Theory ◽  
Wave Dispersion ◽  
Surface Zone ◽  
Surface Wave Dispersion ◽  
Near Surface ◽  
Arrival Times ◽  
Ground Roll

A non‐mathematical summary is presented of the published theories and observations on dispersion, i.e., variation of velocity with frequency, in surface waves from earthquakes and in waterborne waves from shallow‐water explosions. Two further instances are cited in which dispersion theory has been used in analyzing seismic data. In the seismic refraction survey of Bikini Atoll, information on the first 400 feet of sediments below the lagoon bottom could not be obtained from ground wave first arrival times because shot‐detector distances were too great. Dispersion in the water waves, however, gave data on speed variations in the bottom sediments which made possible inferences on the recent geological history of the atoll. Recent systematic observations on ground roll from explosions in shot holes have shown dispersion in the surface waves which is similar in many ways to that observed in Rayleigh waves from distant earthquakes. Classical wave theory attributes Rayleigh wave dispersion to the modification of the waves by a surface layer. In the case of earthquakes, this layer is the earth’s crust. In the case of waves from shot‐holes, it is the low‐speed weathered zone. A comparison of observed ground roll dispersion with theory shows qualitative agreement, but it brings out discrepancies attributable to the fact that neither the theory for liquids nor for conventional solids applies exactly to unconsolidated near‐surface rocks. Additional experimental and theoretical study of this type of surface wave dispersion may provide useful information on the properties of the surface zone and add to our knowledge of the mechanism by which ground roll is generated in seismic shooting.

STUDYING OF SPACE WEATHER ELECTROMAGNETIC PARAMETERS OF IONOSPHERE IN «OBSTANOVKA 1-STEP» EXPERIMENT ON THE RUSSIAN SEGMENT OF THE ISS

2021 ◽  
pp. 20-41
Author(s):  
Stanislav I. KLIMOV ◽  
Valery A. GRUSHIN Valery A ◽  
Kalman BALAJTHY ◽  
Dichko Enchev BACHVAROV ◽  
Serhiy M. BELYAEV ◽  
...  
Keyword(s):  
Plasma Wave ◽  
Space Weather ◽  
Space Station ◽  
Scientific Instrument ◽  
Surface Zone ◽  
Electromagnetic Parameters ◽  
Wave Processes ◽  
Near Surface ◽  
Ionosphere Plasma ◽  
Electric And Magnetic Fields

The program and results of physical research in the international (5 countries) space experiment «The situation (1 stage)», conducted onboard the Russian segment of the International Space Station (ISS) in the period 27.02.2013 to 09.05.2015, is presented. The methods and scientific tasks of the experiment and the composition of the Plasma-wave complex based on the combined wave diagnostics method are described in detail, and designed to conduct geophysical studies through long-term monitoring measurements of the electromagnetic parameters of the ionosphere plasma and plasma-wave processes associated with the manifestation in the ionosphere of the solar-magnetosphere-ionosphere and ionosphere-atmosphere relationships, i. e., parameters of space weather. Studies in the near-surface zone of plasma-wave processes of interaction of an extra-large spacecraft, like ISS, with the ionosphere are necessary for both applied and fundamental geophysical studies. The electric and magnetic fields and currents measured at the surface of the ISS are determined by the parameters of the surrounding ionosphere plasma and the nature of the interaction of the materials on the surface with this medium. Key words: orbital space station, fundamental space research, ionosphere plasma, plasma-wave processes, electromagnetic fields and radiation, scientific instrument, space weather.

scholarly journals Modern Geodetic Measurement Techniques in Gravimetric Studies on the Example of Gypsum Karst in the Siesławice Region

2018 ◽  
Vol 35 ◽  
pp. 03002 ◽  
Author(s):  
Sławomir Porzucek ◽  
Monika Łój ◽  
Karolina Matwij ◽  
Wojciech Matwij
Keyword(s):  
Laser Scanning ◽  
Measurement Techniques ◽  
Three Dimensional ◽  
Digital Terrain Model ◽  
Field Studies ◽  
Surface Zone ◽  
Three Dimensional Model ◽  
Geodetic Measurement ◽  
Near Surface ◽  
Gypsum Karst

In the region of Siesławice (near Busko-Zdrój, Poland) there are unique phenomena of gypsum karst. Atmospheric factors caused numerous gypsum outcrops, canals and underground voids. The article presents the possibility of using non-invasive gravimetric surveys supplemented with geodetic measurements to illustrate karst changes occurring around the void. The use of modern geodetic measurement techniques including terrestrial and airborne laser scanning enables to generate a digital terrain model and a three-dimensional model of voids. Gravimetric field studies allowed to map the anomalies of the gravitational field of the near-surface zone. Geodetic measurement results have made it possible to accurately determine the terrain correction that supplemented the gravimetric anomaly information. Geophysical interpretation indicate the presence of weathered rocks in the near surface zone and fractures and loosened zones located surround the karst cave.

scholarly journals Stress measurement using magnetic Barkhausen noise and metal magnetic memory testing

2010 ◽  
Vol 21 (5) ◽  
pp. 055703 ◽  
Author(s):  
Ping Wang ◽  
Shougao Zhu ◽  
Gui Yun Tian ◽  
Haitao Wang ◽  
John Wilson ◽  
...  
Keyword(s):  
Stress Measurement ◽  
Barkhausen Noise ◽  
Magnetic Memory ◽  
Memory Testing ◽  
Metal Magnetic Memory ◽  
Magnetic Barkhausen Noise ◽  
Metal Magnetic Memory Testing

scholarly journals OS0711 Microstructure near Surface and Fatigue Properties of FPB-treated Pure Titanium

2009 ◽  
Vol 2009 (0) ◽  
pp. 280-281
Author(s):  
Sho NODA ◽  
Tatsuro MORITA ◽  
Hidemasa NAKAGUTI ◽  
Chuji KAGAYA ◽  
Yoshio MIYASAKA
Keyword(s):  
Pure Titanium ◽  
Fatigue Properties ◽  
Near Surface
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