Journal articles: 'Subsurface stress'

1

Qin, Xiao Feng, Da Le Sun, and Li Yang Xie. "Research on the Approach for the Assessment of Subsurface Rolling Contact Fatigue Damage." Applied Mechanics and Materials 395-396 (September 2013): 845–51. http://dx.doi.org/10.4028/www.scientific.net/amm.395-396.845.

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In this paper, the distribution of different critical stresses, which were used in previous correlation articles for the assessment of subsurface rolling contact fatigue damage, was analyzed. The rationality of orthogonal shear stress was selected as the key stress controlling the subsurface rolling contact fatigue damage was clarified. Base on the linear fatigue damage accumulative theory and the modification equation for the range of asymmetrical stress, the influence of friction on subsurface rolling contact fatigue damage was studied. The results show that the subsurface orthogonal shear stress is a completely symmetrical stress when the friction coefficient is zero, while it is an asymmetrical stress with considering the friction. The stress ratio of subsurface orthogonal shear stress and subsurface rolling contact fatigue damage is increased with the increasing of friction.

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Harris, T. A., and Wei Kuei Yu. "Lundberg-Palmgren Fatigue Theory: Considerations of Failure Stress and Stressed Volume." Journal of Tribology 121, no. 1 (January 1, 1999): 85–89. http://dx.doi.org/10.1115/1.2833815.

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Load ratings and fatigue life prediction of rolling bearings is based on the Lundberg-Palmgren theory first published in Sweden in 1947. The basic equation of this theory includes the stressed volume of material in the bearing raceway subsurfaces as a major parameter. This volume of material is simplistically determined to have a nearly rectangular subsurface cross-sectional area bounded by the length of the maximum contact area ellipse and the depth at which the maximum failure-causing stress occurs. The latter stress is assumed to be effective over this area. In fact, a distribution of stress occurs, and in this investigation it is demonstrated that the subsurface volume with a potential for fatigue cracking is substantially different from that used by Lundberg and Palmgren. This difference in volume, particularly in the presence of surface shear stresses, can have a profound effect on the method and prediction of bearing fatigue lives.

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Mizozoe, Syunsuke, and Katsuyuki Kida. "Internal Shear Stress Distribution and Subsurface Cracks of PPS Thrust Bearings under Rolling Contact Fatigue in Water." Key Engineering Materials 858 (August 2020): 101–5. http://dx.doi.org/10.4028/www.scientific.net/kem.858.101.

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In this study, crack propagation in PPS thrust bearings under rolling contact fatigue (RCF) in water was observed, and relation between subsurface crack and internal shear stress parallel to the surface was investigated. It was found the cause of flaking was subsurface crack. They were evaluated in terms of contact stress and friction between their faces. It was discovered that subsurface cracks distributed around shear stress peak, and flaking failure was dominated by subsurface shear stress.

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INABA, Takuma, Takashi KATAGIRI, Hidekazu NOZUE, and Takashi MATSUMURA. "Residual Stress in Subsurface Finished in Milling." Proceedings of The Manufacturing & Machine Tool Conference 2019.13 (2019): A20. http://dx.doi.org/10.1299/jsmemmt.2019.13.a20.

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Bian, Gui Xue, Yue Liang Chen, Jian Jun Hu, and Yong Zhang. "Fatigue Microcrack Initiation and Propagation of Aluminum Alloy under Different Stress Level and Stress Ratio." Advanced Materials Research 239-242 (May 2011): 1495–500. http://dx.doi.org/10.4028/www.scientific.net/amr.239-242.1495.

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The microstructure of fatigue fracture of aluminum alloys under various stresses and stress ratios were studied by optical microscope and scanning electron microscope, and the influences of microstructure features on microcrack initiation and propagation were investigated. The results show that the fatigue microcrack originated from surface or subsurface of specimens. And with the increase of stress ratio, fatigue crack originated from deeper subsurface at the same stress level. With the increase of stress level, fatigue crack originated from shallower subsurface or surface at same stress ratio. There is an increase in crack propagation region as the stress level decreases at the same stress ratio. Increasing of stress ratio, increases crack propagation region under same stress level. Microcrack generally originated from secondary (S phase particles) and larger particles at low stress level and high stress ratio. Microcrack generally originated from larger constituent particles at high stress level and low stress ratio. Microcracks propagation is evidently impeded by grain boundaries at low stress level and high stress ratio.

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Wang, Cheng, Wei Yu, and Cheng Zu Ren. "An Accurate Method for Calculating the Contact Subsurface Stress Field of Hybrid Ceramic Ball Bearing." Solid State Phenomena 175 (June 2011): 215–18. http://dx.doi.org/10.4028/www.scientific.net/ssp.175.215.

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In order to predict fatigue life of hybrid ceramic ball bearing (HCBB) by Ioannides and Harris (IH) theory, the contact subsurface stress field is needed. The contact surfaces of ball and race groove are compatible. The closed-form analytical solution of compatible contact problem is hard to be obtained. The Finite Element Method (FEM) together with submodel technology is adopted to accurately and efficiently calculate the contact deformation and subsurface stress of ball–race groove contact. The result indicated that, the FEM with submodel technology considers the real contact deformation of ball-race groove, and can accurately and efficiently calculate the subsurface stress field. It is believed that the calculated subsurface stress field can be used in IH theory to predict fatigue life of HCBB.

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Elsharkawy, A. A., and B. J. Hamrock. "Subsurface Stresses in Micro-EHL Line Contacts." Journal of Tribology 113, no. 3 (July 1, 1991): 645–55. http://dx.doi.org/10.1115/1.2920673.

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The circular non-Newtonian fluid model associated with a limiting shear strength and the system approach were used to calculate the pressure, surface shear stress, and film thickness profiles in an elastohydrodynamically lubricated conjunction under isothermal conditions. The calculated pressure and surface shear stress were used to evaluate the maximum shear stress and the von Mises equivalent stress distributions in the solids. The effect of the slide-roll ratio for smooth lubricated surfaces, the effect of a single moving irregularity located on one of the smooth lubricated surfaces, and the effect of the amplitude and wavelength of a stationary sinusoidal wavy surface on the pressure, surface shear stress, and film thickness profiles, and hence on the subsurface stress pattern in the solids, were studied.

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Sulaiman, Mohd Syakir, Wani Sofia Udin, and Aweng Eh Rak. "Shear joints and its relations with subsurface structures in Batu Melintang, Jeli, Kelantan, Malaysia." Journal of Tropical Resources and Sustainable Science (JTRSS) 8, no. 2 (August 6, 2021): 86–93. http://dx.doi.org/10.47253/jtrss.v8i2.626.

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Shear joint is the common rock deformation structures formed in Batu Melintang, Jeli due to its location within Bentong-Raub Suture zone. The structural analysis of shear joint can give information about the direction of maximum and minimum stress exerted on a rock while undergoing deformation as the effect of stress fields in the study area. The subsurface structural analysis is done by using the geophysical resistivity method. It displays the subsurface structure in the area for confirmation of the structure found on the surface whether it is highly fractured, moderately fractured or low fractured. The research area was divided into six grids for systematic field measurement. The shear joints orientation were taken while conducting geological mapping and recorded using rose diagram analysis; while the geophysical resistivity method was carried out with a varied length of survey lines set at 200/100m and 1.25/2.5/5m electrode spacing. The subsurface depth of penetration for each survey line is varied, ranging from 0m to 50m. The data is processed in RES2DINV software to obtain the pseudosection profile of the subsurface. The study area principal stress was identified; the maximum stress force ?1 was directed in NW-SE in direction of S107°E and N287°W, while minimum stress ?3 was directed in NE-SW in direction of N17°E and S197°W. The pseudosection subsurface image also displayed a correlation between surface shear joint structures and subsurface structures. The subsurface investigation; according to the pseudosection found that the study area consists of highly fractured structure displayed as several weak zones and fractures of bedrock.

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Zong, Nanfu, Hui Zhang, Yang Liu, and Zhifang Lu. "Analysis of the off-corner subsurface cracks of continuous casting blooms under the influence of soft reduction and controllable approaches by a chamfer technology." Metallurgical Research & Technology 116, no. 3 (2019): 310. http://dx.doi.org/10.1051/metal/2018102.

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In the current study, the morphology of the off-corner subsurface cracks located on the cross section of continuous casting bloom under a soft reduction operation was observed. A 3D thermo-mechanical model was adopted to calculate the temperature history, bulging deformation and stress distributions in the reduction region, and then to analyze the formation of the off-corner subsurface cracks under the influence of soft reduction. The results showed that the off-corner subsurface cracks can be formed under the influence of the extensive stress fields which develop in the cracking temperature range, especially located on the loosed side of the bloom corner region. Adjusting the chamfer angle and chamfer length can decrease stress concentration and bulging deformation to minimize the risk of off-corner subsurface cracks during the soft reduction operation.

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10

Kida, Katsuyuki, Shintaro Hazeyama, Takuma Sado, Koshiro Mizobe, and Takuya Shibukawa. "Crack Initiation Observation in Early Stage of Rolling Contact Fatigue of SUJ2 Using a Single-Ball Apparatus." Applied Mechanics and Materials 620 (August 2014): 421–24. http://dx.doi.org/10.4028/www.scientific.net/amm.620.421.

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A single-ball RCF testing machine was used in order to investigate crack initiation of SUJ2 material at early stage of fatigue. This machine enables observation of a full cross section by sectioning the specimen only once. The RCF tests were carried out under a Hertzian stress of 5.3 GPa, at 3000 rpm. All of the cracks initiated from non-metallic inclusions on 300 mm2sized area were counted, and the relation between the number of cracks and their initiation depths was drawn. Furthermore subsurface shear stress distribution was calculated. Empirical data of the crack distributions and subsurface stress distribution was compared. It was found that the crack starts growing during 3.3×104- 1.0×105cycles by the subsurface shear stress.

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Moeggenborg, Kevin, Ian Manning, Jon Searson, and Gil Yong Chung. "Impact of Subsurface Damage on SiC Wafer Shape." Materials Science Forum 963 (July 2019): 530–33. http://dx.doi.org/10.4028/www.scientific.net/msf.963.530.

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The impact of surface stress due to polish and grind processes on wafer bow was studied as a function of abrasive size. Results indicate that sub-surface damage from these processes can introduce significant surface stress. For polishing processes, this stress is proportional to mean abrasive size. The study also investigates stress as a function of depth below the wafer surface and finds that most stress is concentrated near the wafer surface.

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12

Voskamp, A. P. "Subsurface Residual Stress Concentrations During Rolling Contact Fatigue." Materials Science Forum 347-349 (May 2000): 346–51. http://dx.doi.org/10.4028/www.scientific.net/msf.347-349.346.

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13

Feng, Xi Qiao, and M. Xu. "Solutions of Stress Intensity Factors of Subsurface Cracks." Key Engineering Materials 312 (June 2006): 83–88. http://dx.doi.org/10.4028/www.scientific.net/kem.312.83.

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In the present paper, an integral transform-based method is presented for calculating the stress intensity factors of subsurface cracks. Due to the interaction between the crack and the free surface, the crack tip fields are generally of I-II mixed mode. The solutions for two typical configurations, a Griffith crack and a circular crack beneath the free surface of a semi-infinite solid, are derived.

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14

Ma, Chien‐Ching, and Szu‐Kuzi Chen. "Dynamic Stress Intensity Factor for Subsurface Inclined Cracks." Journal of Engineering Mechanics 120, no. 3 (March 1994): 483–98. http://dx.doi.org/10.1061/(asce)0733-9399(1994)120:3(483).

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15

Hanson, Mark T., and Igusti W. Puja. "Elastic Subsurface Stress Analysis for Circular Foundations. I." Journal of Engineering Mechanics 124, no. 5 (May 1998): 537–46. http://dx.doi.org/10.1061/(asce)0733-9399(1998)124:5(537).

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Hanson, Mark T., and Igusti W. Puja. "Elastic Subsurface Stress Analysis for Circular Foundations. II." Journal of Engineering Mechanics 124, no. 5 (May 1998): 547–55. http://dx.doi.org/10.1061/(asce)0733-9399(1998)124:5(547).

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17

Mihailidis, A., V. Bakolas, and N. Drivakos. "Subsurface stress field of a dry line contact." Wear 249, no. 7 (July 2001): 546–56. http://dx.doi.org/10.1016/s0043-1648(01)00542-7.

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18

Pickard, Andrew C., and David E. Mills. "Modeling of subsurface ceramic inclusions in metallic matrices." Journal of Strain Analysis for Engineering Design 55, no. 5-6 (March 19, 2020): 134–44. http://dx.doi.org/10.1177/0309324720910935.

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All engineering materials have the potential to contain inhomogeneities that can act as initiators for fatigue cracks during cyclic loading. One class of inhomogeneity that can occur as a result of the processes used to create metallic materials is a ceramic inclusion, typically resulting from the raw material contamination during the melting process. This article examines the predicted behavior of hard ceramic inclusions in a nickel-base superalloy metallic matrix. Compressive residual stresses are created in the inclusion during cool down from a stress-free state at high temperature. The influence of the proximity of the inclusion to the surface of the matrix material is examined, together with the impact of subsequent uniaxial loading on the stress field in the inclusion and in the surrounding material. The stress field in the ceramic inclusion is observed to transition from compressive to tensile as a function of the proximity of the inclusion to the surface of the material and the applied uniaxial stress field. For deep subsurface inclusions, the uniaxial stress field required to achieve a tensile stress in the inclusion is close to the yield stress of the material. The sensitivity of this critical stress to material cyclic hardening behavior and to the temperature difference between the stress-free state and the operating state is also explored. The significance of these modeling results is discussed in terms of the sensitivity of nickel-base superalloys to crack formation and growth from ceramic inclusions and hence the impact on probabilistic fatigue life assessments of the presence, location and size of the ceramic inclusions.

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Hua, D. Y., K. Farhang, and L. E. Seitzman. "A Multi-Scale System Analysis and Verification for Improved Contact Fatigue Life Cycle of a Cam-Roller System." Journal of Tribology 129, no. 2 (January 9, 2007): 321–25. http://dx.doi.org/10.1115/1.2540572.

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Surface distress in the form of contact fatigue is encountered in cam-roller systems. The contact fatigue appears to be initiated at micrometer-scale subsurface region. High stress is a result of the macro-scale requirement on the cam-roller motion event that produces high contact loads due to inertia of the roller and its follower link. Sliding of the roller and its impact onto the cam surface further compounds the detrimental effect of contact load. While conventionally a Hertz contact stress analysis can be used in ascertaining contact stress and maximum subsurface von Mises stress, it generally underestimates the stress when compared to the micrometer-scale subsurface stresses due to the presence of surface roughness. Contact analyses of cam and roller with rough surfaces are performed to examine the effects of two surface treatments. These involve surface finishing process in which a surface is rendered smooth, and the addition of a coating to the roller surface. Measurements of such cam and roller surfaces are used in micro-contact analysis module of a Surface Distress Analytical Toolkit to examine the effect of surface finish and coating on maximum subsurface stress. It is found that smooth surface provides a 53% reduction in maximum subsurface stress. The analysis also shows that the addition of coating further reduces subsurface stress nearly 7%. The impact of the combined treatment of the surface is an increase in contact fatigue life of the cam-roller system by nearly two orders of magnitude. The above findings are confirmed by laboratory tests using six rollers with various degrees of finishing processes, and with and without addition of coating to the surfaces. Examination of the rollers indicates a general improvement in roller performance due to addition of coating. Most notably, the combination of finishing process and coating was found to provide the best contact fatigue life since the corresponding rollers showed no observable wear even after testing for 2161h, or the same number of cycles accumulated over about 500,000 truck miles.

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20

Mann, J. B., T. N. Farris, and S. Chandrasekar. "Effects of Friction on Contact of Transverse Ground Surfaces." Journal of Tribology 116, no. 3 (July 1, 1994): 430–37. http://dx.doi.org/10.1115/1.2928858.

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The two-dimensional plane-strain sliding contact of a smooth rigid roller on a transverse ground rough surface is analyzed. The rough surface is idealized as an elastic half-space with periodic roughness modeled as cylindrical ridges oriented transverse to the sliding direction. The contact problem is solved using a numerical iterative method in which each asperity contact is treated as a micro-Hertz contact, and the exact treatment of asperity interaction is included. The subsurface stress field is calculated using Westergaard stress functions. The subsequent analysis compares the rough surface stress fields with the corresponding smooth Hertz contact to evaluate the influence of surface roughness and friction on the subsurface stress distributions. The results show that the real area of contact is less than the corresponding smooth surface Hertz contact area, and the magnitude of the actual localized maximum contact pressure is always greater than the corresponding smooth surface contact pressure. The asperity level subsurface effective stresses are greater in magnitude than the maximum subsurface stress due to the macro-Hertz contact for low coefficients of friction, and for high coefficients of friction the maximum effective stresses occur on the bulk material surface.

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21

Chan, K. L. "Generation of the Solar Subsurface Shear." Symposium - International Astronomical Union 203 (2001): 173–76. http://dx.doi.org/10.1017/s0074180900219001.

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It is well known that a thin layer of angular velocity shear exists just below the solar surface. We propose that this layer is primarily generated by the radial-meridional component of the Reynolds stress. This Reynolds stress component is created by a characteristic upward-equatorward (or equivalently, downward-poleward) correlation of the turbulence velocity over a region in which the shear layer is embedded. Using 2D and 3D numerical experiments, we illustrate that this correlation is caused by vortices that get sucked down from the surface and turn aligned with the rotation vector (a la Taylor columns).

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Gu, Zonglin, Caichao Zhu, Huaiju Liu, and Jinyuan Tang. "Subsurface stress-field analysis of generating ground helical gear based on finite line-contact mixed elastohydrodynamic lubrication." Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology 235, no. 1 (May 13, 2020): 3–17. http://dx.doi.org/10.1177/1350650120925574.

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Tooth surface roughness and lubrication status have significant influence on the contact performance and fatigue life of helical gear pair. Yet, despite the development in elastohydrodynamic lubrication-based contact analysis and solution of subsurface stress field, researches in subsurface stress field of helical gears considering both lubrication and surface roughness are not quite comprehensive. In this study, three-dimensional surface roughness of generating ground gear is measured, a finite line-contact mixed elastohydrodynamic lubrication model is established to perform the contact analysis, and, on this basis, the influence of tooth surface roughness on the subsurface stress field is studied. Results show that compared with the smooth surface, the overall level of subsurface stress is raised; maximum stress values and plastic zones occur in the close vicinity of tooth surface, which adds to the risk of surface failure; within sections in the valley regions of roughness, locations of maximum stresses are generally similar to the smooth surface situation, i.e. in relatively deep zones, while within sections in the peak regions, the majority of locations with maximum stresses shift much closer to the surface; contact pressure and stress status see only mild undulation between different sections distributed along the contact line, but intense changes between sections distributed along the entraining direction.

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Fischer, F. D., K. Mayrhofer, and E. Parteder. "ELLIPTICAL SUBSURFACE CRACKS UNDER A NORMAL STRESS AND A RESIDUAL STRESS FIELD." Fatigue & Fracture of Engineering Materials & Structures 19, no. 1 (April 2, 2007): 129–39. http://dx.doi.org/10.1111/j.1460-2695.1996.tb00938.x.

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Shiozawa, Kazuaki, and L. Lu. "Effect of Non-Metallic Inclusion Size and Residual Stresses on Gigacycle Fatigue Properties in High Strength Steel." Advanced Materials Research 44-46 (June 2008): 33–42. http://dx.doi.org/10.4028/www.scientific.net/amr.44-46.33.

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Fatigue fracture of some high-strength steels occurs at small defect in the subsurface zone of a material at low stress amplitude level and in a high-cycle region of more than 106 cycles (gigacycle fatigue life), whereas surface fatigue crack initiation occurs at high-stress amplitude and low cycles. There is a definite stress range where the crack initiation site changes from a surface to a subsurface defect, giving a step-wise S-N curve or a duplex S-N curve. From the experimental results, fatigue fracture mode was classified into three types, such as, surface inclusion induced fracture mode, subsurface inclusion induced fracture mode without granular bright facet (GBF) area and that with the GBF, depending on stress amplitude level and stress ratio. The GBF area was observed in the vicinity of a non-metallic inclusion at the fracture origin inside the fish-eye in gigacycle fatigue regime. It was made clear from the discussion with fracture mechanics that the transition of fracture mode was affected by compressive residual stresses on the specimen surface. Fracture-mode transition diagram was proposed through the experimental and theoretical investigation. Also, from the evaluation of the fatigue life based on the estimated subsurface crack growth rate from the S-N data, effect of inclusion size on the dispersion of fatigue life was explained, and S-N curve for subsurface inclusion-induced fracture depended on the inclusion size was provided.

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Kida, Katsuyuki, Takashi Honda, Yoshihiko Seto, Edson Costa Santos, and Takuya Shibukawa. "Single-Ball Rolling Contact Fatigue of 13Cr-2Ni-2Mo Stainless Steels Quenched by Induction Heating Method." Applied Mechanics and Materials 300-301 (February 2013): 1372–76. http://dx.doi.org/10.4028/www.scientific.net/amm.300-301.1372.

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Rolling contact fatigue tests of 20mm-diameter 13Cr-2Ni-2Mo stainless steel bars was carried out using a newly developed single-ball system. The bars were quenched by induction heating method and after that tempered. Sectional observations of the subsurface cracks were made after the surface layer separations. Based on the observations, stress analysis was performed in order to investigate the relation between flaking failures and subsurface crack growth. From these calculations it was found that the shear stress propagated subsurface cracks and finally caused the flaking failures. Furthermore, eight specimens were fatigue tested and Weibull statics distribution of RCF life were calculated using Johnson's statistical method. It was found that the basic life (L10) of the bars under 5.3GPa Hertzian stress was 8.33×106 cycles.

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Oponowicz, Adrian, Marianna Marciszko-Wiąckowska, Andrzej Baczmański, Manuela Klaus, Christoph Genzel, Sebastian Wroński, Kamila Kollbek, and Mirosław Wróbel. "Gradient of Residual Stress and Lattice Parameter in Mechanically Polished Tungsten Measured Using Classical X-rays and Synchrotron Radiation." Metallurgical and Materials Transactions A 51, no. 11 (September 4, 2020): 5945–57. http://dx.doi.org/10.1007/s11661-020-05967-y.

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Abstract In this work, the stress gradient in mechanically polished tungsten sample was studied using X-ray diffraction methods. To determine in-depth stress evolution in the very shallow subsurface region (up to 10 μm), special methods based on reflection geometry were applied. The subsurface stresses (depth up to 1 μm) were measured using the multiple-reflection grazing incidence X-ray diffraction method with classical characteristic X-rays, while the deeper volumes (depth up to 10 μm) were investigated using energy-dispersive diffraction with white high energy synchrotron beam. Both complementary methods allowed for determining in-depth stress profile and the evolution of stress-free lattice parameter. It was confirmed that the crystals of tungsten are elastically isotropic, which simplifies the stress analysis and makes tungsten a suitable material for testing stress measurement methods. Furthermore, it was found that an important compressive stress of about − 1000 MPa was generated on the surface of the mechanically polished sample, and this stress decreases to zero value at the depth of about 9 μm. On the other hand, the strain-free lattice parameter does not change significantly in the examined subsurface region.

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Chen, Ren, and Lin. "Effect of Stress Wave between Adjacent Asperities Interaction on Subsurface Damage of Optical Glass in Precision Grinding." Materials 12, no. 8 (April 15, 2019): 1239. http://dx.doi.org/10.3390/ma12081239.

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The interaction between adjacent asperities is a typical characteristic of the grinding process and plays an important role in the material removal mechanism. Therefore, in order to systematically investigate the formation mechanism of the subsurface damage, a precision grinding contact model between the diamond particle and optical glass with adjacent asperities is proposed in our research. The initiation and propagation mechanism of median/lateral cracks under residual stress, the propagation rules of the stress waves on the subsurface, and the interaction between the subsurface damage under stress superposition effect are fully investigated by a theoretical analysis and finite element simulation. The simulation results of the precision grinding model are verified by experiments, which show that the proposed numerical analysis model is reasonable and the finite element analysis process is feasible.

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Arakere, Nagaraj K., Erik Knudsen, Gregory R. Swanson, Gregory Duke, and Gilda Ham-Battista. "Subsurface Stress Fields in Face-Centered-Cubic Single-Crystal Anisotropic Contacts." Journal of Engineering for Gas Turbines and Power 128, no. 4 (November 3, 2005): 879–88. http://dx.doi.org/10.1115/1.2180276.

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Single-crystal superalloy turbine blades used in high-pressure turbomachinery are subject to conditions of high temperature, triaxial steady and alternating stresses, fretting stresses in the blade attachment and damper contact locations, and exposure to high-pressure hydrogen. The blades are also subjected to extreme variations in temperature during start-up and shutdown transients. The most prevalent high-cycle fatigue (HCF) failure modes observed in these blades during operation include crystallographic crack initiation/propagation on octahedral planes and noncrystallographic initiation with crystallographic growth. Numerous cases of crack initiation and crack propagation at the blade leading edge tip, blade attachment regions, and damper contact locations have been documented. Understanding crack initiation/propagation under mixed-mode loading conditions is critical for establishing a systematic procedure for evaluating HCF life of single-crystal turbine blades. This paper presents analytical and numerical techniques for evaluating two- and three-dimensional (3D) subsurface stress fields in anisotropic contacts. The subsurface stress results are required for evaluating contact fatigue life at damper contacts and dovetail attachment regions in single-crystal nickel-base superalloy turbine blades. An analytical procedure is presented for evaluating the subsurface stresses in the elastic half-space, based on the adaptation of a stress function method outlined by Lekhnitskii (1963, Theory of Elasticity of an Anisotropic Elastic Body, Holden-Day, Inc., San Francisco, pp. 1–40). Numerical results are presented for cylindrical and spherical anisotropic contacts, using finite element analysis. Effects of crystal orientation on stress response and fatigue life are examined. Obtaining accurate subsurface stress results for anisotropic single-crystal contact problems require extremely refined 3D finite element grids, especially in the edge of contact region. Obtaining resolved shear stresses on the principal slip planes also involves considerable postprocessing work. For these reasons, it is very advantageous to develop analytical solution schemes for subsurface stresses, whenever possible.

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Fischer, Karsten, Andrew Pearce, Xavier Garcia-Teijeiro, Andrew Mallinson, Ian Lloyd, Stephen Anderson, Francisco Gomez, Saad Kisra, and Adrian Rodriguez-Herrera. "Seismic-scale finite element stress modeling of the subsurface." Geomechanics for Energy and the Environment 28 (December 2021): 100245. http://dx.doi.org/10.1016/j.gete.2021.100245.

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Ludian, Tomasz, Marcin Kocan, Henry J. Rack, and Lothar Wagner. "Residual-stress-induced subsurface crack nucleation in titanium alloys." International Journal of Materials Research 97, no. 10 (October 2006): 1425–31. http://dx.doi.org/10.3139/146.101387.

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31

Song, Wen Jie, and Wei Li. "Subsurface Crack Initiation and Propagation Mechanisms in Very High Cycle Regime." Advanced Materials Research 482-484 (February 2012): 1524–29. http://dx.doi.org/10.4028/www.scientific.net/amr.482-484.1524.

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Rotary bending fatigue test was adopted to study the subsurface fracture property of a low alloy steel in very high cycle regime. As a result, the subsurface crack initiation and propagation with fine granular area (FGA) induced by subsurface incision is the predominant reason for fatigue facture of this low alloy steel in very high cycle regime of N>106, which can be divided into three stages to discuss: (I) small crack propagation inside of FGA, (II) stable crack propagation in the fish-eye region outside of FGA and (III) final catastrophic fracture outside of fish-eye. The crack growth rate in the first stage is lower than 10-11m/cycle, which means that the progress of FGA formation is extremely slow and consumes the great majority of total fatigue life. The interior stress intensity factor range corresponding to subsurface inclusion and the stress intensity factor ranges of FGA and fish-eye (ΔKint-th, ΔKFGA and ΔKfish-eye) can be regarded as the threshold values of controlling subsurface crack propagation in these three stages, respectively.

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Voskamp, A. P. "Material Response to Rolling Contact Loading." Journal of Tribology 107, no. 3 (July 1, 1985): 359–64. http://dx.doi.org/10.1115/1.3261078.

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The material response to rolling contact loading has been analyzed using quantitative X-ray diffraction methods. This has led to the discovery of preferred crystalline orientation in very narrow subsurface regions of endurance-tested 6309 deep groove ball bearing inner rings. The high hydrostatic pressure field, derived from the load-induced three-dimensional stress field in each Hertzian contact load cycle, allows substantial microplastic deformation to be accommodated in the subsurface layers. This microplastic deformation is accompanied by transformation of retained austenite, decay of martensite and the development of texture and residual stresses, one of which is a subsurface tensile stress in a direction normal to the surface. Both the preferred orientation and the tensile residual stress allow for crack propagation parallel to the rolling contact surface. Based on these findings, an outline of a qualitative model for rolling contact fatigue is presented.

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Denkena, Berend, and Bernd Breidenstein. "Pre PVD-Coating Processes and their Effect on Substrate Residual Stress in Carbide Cutting Tools." Key Engineering Materials 438 (May 2010): 17–22. http://dx.doi.org/10.4028/www.scientific.net/kem.438.17.

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Cohesive damage of PVD-coated cemented carbide cutting tools is ascribed to the residual stress state of the substrate subsurface. The present paper shows the formation of the substrate residual stress in the process chain as well as the stability of the single process steps referred to the scattering of the residual stress values. Depth resolved residual stress measurements across coating and substrate subsurface show a layer in the substrate, where possibly tensile stress occurs, from where cohesive damage may be initialized during tool use. Results of experiments are presented, where the influence of parameter variations in pre coating processes on the residual stress state is investigated. The characteristics of compressive residual substrate stress during the final PVD-process is presented as well as a correlation between coating and substrate stress.

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Czan, Andrej, Jozef Holubjak, Igor Daniš, Juraj Martinček, Matej Mikloš, Robert Čep, Michal Hatala, and Šarka Malotova. "Analysis of residual stress in subsurface layers after precision hard machining of forging tools." MATEC Web of Conferences 157 (2018): 01005. http://dx.doi.org/10.1051/matecconf/201815701005.

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This paper is focused on analysis of residual stress of functional surfaces and subsurface layers created by precision technologies of hard machining for progressive constructional materials of forging tools. Methods of experiments are oriented on monitoring of residual stress in surface which is created by hard turning (roughing and finishing operations). Subsequently these surfaces were etched in thin layers by electro-chemical polishing. The residual stress was monitored in each etched layer. The measuring was executed by portable X-ray diffractometer for detection of residual stress and structural phases. The results significantly indicate rise and distribution of residual stress in surface and subsurface layers and their impact on functional properties of surface integrity.

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Kim, Tae Wan, Sang Don Lee, and Yong Joo Cho. "Contact Fatigue Life Prediction under EHL Contact." Key Engineering Materials 297-300 (November 2005): 22–27. http://dx.doi.org/10.4028/www.scientific.net/kem.297-300.22.

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In this study, the simulation of contact fatigue based on stress analysis is conducted under Elastohydrodynamic Lubrication (EHL) state. To predict a crack initiation life accurately, it is necessary to calculate contact stress and subsurface stresses accurately. Contact stresses are obtained by contact analysis of a semi-infinite solid based on the use of influence functions and the subsurface stress is obtained using rectangular patch solutions. The numerical algorithm using newton-rapson method was constructed to calculate the EHL pressure. Based on these stress values, three multiaxial high-cycle fatigue criteria are used. As a result, the effects of EHL on contact fatigue life are calculated.

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Dai, Houfu, Shaobo Li, and Genyu Chen. "Molecular dynamics simulation of subsurface damage mechanism during nanoscratching of single crystal silicon." Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology 233, no. 1 (March 27, 2018): 61–73. http://dx.doi.org/10.1177/1350650118765351.

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Three-dimension molecular dynamics (MD) simulation is employed to investigate the nanoscratching process of monocrystalline silicon with diamond tools. The effects of tool geometry on subsurface damage and scratching surface integrity are investigated by analyzing phase transformation, chip, defect atoms, hydrostatic stress, von Mises stress and workpiece deformation. In addition, a theoretical analytical model to study the subsurface damage mechanism by analyzing the zone size of phase transformation and normal force with diamond tools at different half-apex angles on silicon surfaces is established. The results show that a bigger half apex angle causes a higher hydrostatic stress, a larger chip volume, a higher temperature and a higher potential energy, and increases subsurface damage. The results also reveal that the evolution of crystalline phases is consistent with the distribution of hydrostatic stress and temperature. In addition, tip scratching with a bigger half-apex angle would result in a larger scratching force and a bigger phase transformation zone, which is in good agreement with the results of the theoretical analytical model.

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Ventura, Carlos EH, Bernd Breidenstein, and Berend Denkena. "Influence of customized cutting edge geometries on the workpiece residual stress in hard turning." Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture 232, no. 12 (January 6, 2017): 2132–39. http://dx.doi.org/10.1177/0954405416685388.

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Depending on the intensity of mechanical and thermal loads during hard turning, compressive and/or tensile residual stress can be obtained. However, only compressive residual stress contributes to avoid crack initiation and propagation and increase fatigue life. In order to induce compressive residual stress in the workpiece surface and subsurface, cutting edge geometry is one of the most important influence factors. Taking this into account, the influence of new customized cutting edge geometries on the parameters of a hook-shaped residual stress profile (typical of a hard turning process) is investigated and possible causes for the encountered phenomena are explained. It was found that edge geometries, which provide an increase in contact length between tool and workpiece, lead to higher compressive residual stress in the subsurface and deeper affected zones.

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Czan, Andrej, Lucia Zauskova, Michal Sajgalik, and Mario Drbul. "Triaxial Measurement Method for Analysis of Residual Stress after High Feed Milling by X-Ray Diffraction." Technological Engineering 13, no. 2 (December 1, 2016): 31–33. http://dx.doi.org/10.2478/teen-2016-0019.

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Abstract Surface integrity is a broad term which includes various quality factors affecting the functional properties of parts. Residual stress is one of these factors. Machining generates residual stresses in the surface and subsurface layers of the structural elements. X-ray diffractometry is a non-destructive method applicable for the measurement of residual stresses in surface and subsurface layers of components. The article is focused on the non-destructive progressive method of triaxial measurement of residual stress after machining the surface of sample by high feed milling technology. Significance of triaxial measuring is the capability of measuring in different angles so it is possible to acquire stress tensor containing normal and shear stress components acting in the spot of measuring, using a Cartesian coordinate system.

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Zou, Zhouyiao, Yanpeng Hao, Yao Zheng, Weiming He, Fangyuan Tian, Lin Yang, and Licheng Li. "Subsurface Stress Measurement in GIS Epoxy Composite by Using LCR Waves." Energies 13, no. 14 (July 20, 2020): 3725. http://dx.doi.org/10.3390/en13143725.

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Internal stress in basin insulators of gas-insulated metal-enclosed switchgear (GIS) can lead to cracks, which affects the safe operation of these apparatuses. In this research, we proposed a subsurface internal stress measurement method for GIS epoxy composites. This method is based on an ultrasonic longitudinal critically refracted (LCR) wave technique. In this study, some epoxy composite specimens were synthesized with similar materials and manufacturing processes to those of 252 kV GIS basin insulators. An ultrasonic stress measurement system that utilized the LCR wave technique was set-up to investigate the relationship between stress and LCR wave propagation time, as well as to measure the compressive stress of the epoxy specimen within 0–50 MPa. The results show that LCR wave propagation time linearly decreased when stress increased in the subsurface zone and the acoustoelastic coefficient was −4.95. We found the relative errors of stress measurements to be less than 13%.

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Morales-Espejel, Guillermo E., and Antonio Gabelli. "Application of a rolling bearing life model with surface and subsurface survival to hybrid bearing cases." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 233, no. 15 (May 8, 2019): 5491–98. http://dx.doi.org/10.1177/0954406219848470.

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A previously published rolling bearing life model that separates the surface and subsurface survival is briefly summarised. The model is applied to the case of hybrid bearings and discussed with regard to a selected set of application examples. Ball hybrid bearings under equal load condition show 12% higher Hertzian stress than all-steel bearings. However, field applications, typically under light load, poor lubrication and contamination, show that hybrid bearings have longer fatigue life than all-steel bearings. Traditional all-steel life models fail to predict this type of behaviour. In this paper, it is shown that hybrid bearing unique fatigue performance can be described using the idea of separation of surface and subsurface survival. The model applies the classical rolling contact fatigue in the subsurface region of the rolling contact while a newly developed tribologically dependent surface degradation models is used for the ceramic-steel raceway interface. It is found that the particular fatigue resistance of the ceramic-steel interface of the hybrid bearing raceway can, in most cases, compensate for the additional stress present in the subsurface region of the contact.

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Xu, Zongwei, Zhongdu He, Ying Song, Xiu Fu, Mathias Rommel, Xichun Luo, Alexander Hartmaier, Junjie Zhang, and Fengzhou Fang. "Topic Review: Application of Raman Spectroscopy Characterization in Micro/Nano-Machining." Micromachines 9, no. 7 (July 21, 2018): 361. http://dx.doi.org/10.3390/mi9070361.

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The defects and subsurface damages induced by crystal growth and micro/nano-machining have a significant impact on the functional performance of machined products. Raman spectroscopy is an efficient, powerful, and non-destructive testing method to characterize these defects and subsurface damages. This paper aims to review the fundamentals and applications of Raman spectroscopy on the characterization of defects and subsurface damages in micro/nano-machining. Firstly, the principle and several critical parameters (such as penetration depth, laser spot size, and so on) involved in the Raman characterization are introduced. Then, the mechanism of Raman spectroscopy for detection of defects and subsurface damages is discussed. The Raman spectroscopy characterization of semiconductor materials’ stacking faults, phase transformation, and residual stress in micro/nano-machining is discussed in detail. Identification and characterization of phase transformation and stacking faults for Si and SiC is feasible using the information of new Raman bands. Based on the Raman band position shift and Raman intensity ratio, Raman spectroscopy can be used to quantitatively calculate the residual stress and the thickness of the subsurface damage layer of semiconductor materials. The Tip-Enhanced Raman Spectroscopy (TERS) technique is helpful to dramatically enhance the Raman scattering signal at weak damages and it is considered as a promising research field.

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Xiong, Ying, Bin Fang, Jinhua Zhang, Ke Yan, and Yongsheng Zhu. "Subsurface stresses analysis of flexible ball bearing with bendable races in a harmonic reducer by superimposition method." Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology 236, no. 6 (November 3, 2021): 1244–59. http://dx.doi.org/10.1177/13506501211049957.

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The bending of races of the flexible ball bearing in a harmonic reducer inevitably results in significant hoop stresses, which leads to the bearing working under a complex stress state. Studies show that hoop stresses can affect bearing life considerably, and subsurface stresses are the fundamental nature of the bearing failure mechanism. This paper established a simplified theoretical model of subsurface stresses for flexible ball bearing by considering bending deformation and contact deformation. First, the plane curved bar theory was used to solve the hoop stresses of the races caused by bending deformation. Second, the hoop stresses were superimposed on the Hertzian principal stresses generated by the contact load to calculate the maximum shearing stress of the raceway. Then, the influence of hoop stresses on subsurface stresses of both the inner and outer races was analyzed based on the proposed model. The results indicated that the subsurface stresses of the inner race calculated by the model were in good agreement with that of the cam-inner race-single ball contact finite element model. In addition, hoop stresses of the inner race increase the maximum shearing stress but decrease its depth to the contact surface, making the inner race more prone to spalling failure, while the outer race is the opposite. At last, the influence of the design parameters of flexible ball bearing on the subsurface stresses of races was studied to provide a theoretical basis for the optimization design of flexible ball bearing and its fatigue failure analysis.

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Farag, A. A. "CROP WATER STRESS INDEX FOR POTATO UNDER SUBSURFACE DRIP IRRIGATION." Misr Journal of Agricultural Engineering 37, no. 1 (January 1, 2020): 23–38. http://dx.doi.org/10.21608/mjae.2020.94968.

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Gabr, M. A., and T. J. Hunter. "Stress-strain analysis of geogrid-supported liners over subsurface cavities." Geotechnical and Geological Engineering 12, no. 2 (June 1994): 65–86. http://dx.doi.org/10.1007/bf00429767.

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Lott, Donovan J., Dequan Zou, and Michael J. Mueller. "Pressure gradient and subsurface shear stress on the neuropathic forefoot." Clinical Biomechanics 23, no. 3 (March 2008): 342–48. http://dx.doi.org/10.1016/j.clinbiomech.2007.10.005.

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46

Szelążek, Jacek. "Sets of Piezoelectric Probeheads for Stress Evaluation with Subsurface Waves." Journal of Nondestructive Evaluation 32, no. 2 (March 9, 2013): 188–99. http://dx.doi.org/10.1007/s10921-013-0172-1.

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Martini, A., B. Escoffier, Q. Wang, S. B. Liu, L. M. Keer, D. Zhu, and M. Bujold. "Prediction of subsurface stress in elastic perfectly plastic rough components." Tribology Letters 23, no. 3 (September 2, 2006): 243–51. http://dx.doi.org/10.1007/s11249-006-9062-3.

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48

Guo, Y. B., and S. Anurag. "Finite element modeling of residual stress profile patterns in hard turning." Powder Diffraction 24, S1 (June 2009): S22—S25. http://dx.doi.org/10.1154/1.3133135.

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Hard turning, i.e., turning hardened steels, may produce the unique “hook” shaped residual stress (RS) profile characterized by surface compressive RS and subsurface maximum compressive RS. However, the formation mechanism of the unique RS profile is not yet known. In this study, a novel hybrid finite element modeling approach based on thermal-mechanical coupling and internal state variable plasticity model has been developed to predict the unique RS profile patterns by hard turning AISI 52100 steel (62 HRc). The most important controlling factor for the unique characteristics of residual stress profiles has been identified. The transition of maximum residual stress at the surface to the subsurface has been recovered by controlling the plowed depth. The predicted characteristics of residual stress profiles favorably agree with the measured ones. In addition, friction coefficient only affects the magnitude of surface residual stress but not the basic shape of residual stress profiles.

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Willert, Emanuel. "Explicit Analytic Solutions for the Subsurface Stress Field in Single Plane Contacts of Elastically Similar Truncated Cylinders or Wedges." Applied Mechanics 3, no. 4 (November 29, 2022): 1337–51. http://dx.doi.org/10.3390/applmech3040077.

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As has been pointed out recently, a possible solution strategy to the wear–fatigue dilemma in fretting, operating on the level of contact mechanics and profile geometries, can be the introduction of “soft” sharp edges to the contact profiles, for example, by truncating an originally smooth profile. In that regard, analysis of possible mechanical failure of a structure, due to the contact interaction, requires the knowledge of the full subsurface stress state resulting from the contact loading. In the present manuscript, a closed-form exact solution for the subsurface stress state is given for the frictional contact of elastically similar truncated cylinders or wedges, within the framework of the half-plane approximation and a local-global Amontons–Coulomb friction law. Moreover, a fast and robust semi-analytical method, based on the appropriate superposition of solutions for parabolic contact, is proposed for the determination of the subsurface stress fields in frictional plane contacts with more complex profile geometries, and compared with the exact solution. Based on the analytical solution, periodic tangential loading of a truncated cylinder is considered in detail, and important scalar characteristics of the stress state, like the von-Mises equivalent stress, maximum shear stress, and the largest principal stress, are determined. Positive (i.e., tensile) principal stresses only exist in the vicinity of the contact edge, away from the pressure singularity at the edge of the profile, and away from the maxima of the von-Mises equivalent stress, or the maximum shear stress. Therefore, the fretting contact should not be prone to fatigue crack initiation.

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Alkaisee, Rasha, and Ru Lin Peng. "Influence of Layer Removal Methods in Residual Stress Profiling of a Shot Peened Steel Using X-Ray Diffraction." Advanced Materials Research 996 (August 2014): 175–80. http://dx.doi.org/10.4028/www.scientific.net/amr.996.175.

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For X-Ray Diffraction Measurement of Depth Profiles of Residual Stress, Step-Wise Removal of Materials has to be Done to Expose the Underneath Layers to the X-Rays. this Paper Investigates the Influence of Layer Removal Methods, Including Electro-Polishing in Two Different Electrolytes and Chemical Etching, on the Accuracy of Residual Stress Measurement. Measurements on Two Shot-Peened Steels Revealed Large Discrepancy in Subsurface Distributions of Residual Stress Obtained with the Respective Methods. Especially, the Chemical Etching Yielded much Lower Subsurface Compressive Stresses than the Electro-Polishing Using a so Called AII Electrolyte. the Difference was Explained by the Influence of the Different Layer Removal Methods on the Microscopic Roughness.

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Journal articles on the topic 'Subsurface stress'

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