A New Strengthening-Polishing Bearings Equipment Based on the Anti-Fatigue Manufacturing Technology

2011 ◽  
Vol 328-330 ◽  
pp. 2211-2214
Author(s):  
Hao Wang ◽  
Xiao Chu Liu ◽  
Chuan Jian Liu ◽  
Wen Xiong Li
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Tensile Stress ◽  
Field Testing ◽  
Manufacturing Technology ◽  
Residual Tensile Stress ◽  
Surface Residual Stress ◽  
Bearing Ring ◽  
Theoretical Design

Aimed to eliminate the harmful residual tensile stress produced on the surface of bearing ring in the conventional bearing processing and join the automatically strengthen and polished technology together, the paper provide a set of new strengthening-polishing bearings equipment, designed to effectively improve the bearing surface’s quality and produce the surface residual stress which can extend the bearing’s fatigue life. The prototype, based on the pre-theoretical design, has been successfully developed, and now is in field testing.

scholarly journals Relaxation Behavior of Residual Stress on Deck-to-Rib Welded Joints by Fatigue Loading in an Orthotropic Bridge Deck

2019 ◽  
Author(s):  
Wen Zhong ◽  
You-liang Ding ◽  
Yong-sheng Song ◽  
Fang-fang Geng
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Stress State ◽  
Stress Relaxation ◽  
Tensile Stress ◽  
Bridge Deck ◽  
Residual Tensile Stress ◽  
Longitudinal Stress ◽  
Welding Seam ◽  
Vehicle Load

To accurately evaluate the influence of the actual tension and compression state and stress ratio at the deck-to-rib welding seam position on the fatigue life of a bridge deck, this paper establishes a coupled stress analysis model that considers the welding residual stress and vehicle stress. Taking the Jiangyin Bridge as an example, a qualitative analysis of the fatigue life under the vehicle load and residual stress field is carried out using the proposed method. A case analysis showed that when the residual tensile stress in the welding seam position is superimposed on the mainly tensile cyclic vehicle load stress, the longitudinal stress relaxation exceeds the peak vehicle load stress; significant longitudinal stress relaxation occurred, while the transverse stress relaxation is not significant. However, when the residual tensile stress is superimposed on the mainly compressive cyclic vehicle load stress, the relaxations of both the longitudinal and transverse stresses are not obvious. Compared with the stress state of the welding point under the action of only the vehicle stress, when the coupling effect of the residual stress and vehicle stress is considered, i.e., the loading condition, the fatigue stress state of the weld point has undergone an essential change under cyclic compressive stress, that is, the compressive stress state that does not require a fatigue check is changed to the tensile stress state. Although the fatigue state of the tensile stress cycle condition has not changed, the fatigue life is reduced by varying degrees under either the compressive or tensile condition.

Research on Surface Residual Stress of Nano-Composite Ceramics under Multi-Frequency Ultrasonic Grinding and Dressing

2011 ◽  
Vol 487 ◽  
pp. 447-451 ◽  
Author(s):  
Bo Zhao ◽  
Jin Xue Xue ◽  
M.L. Zhao
Keyword(s):  
Residual Stress ◽  
Tensile Stress ◽  
Ultrasonic Vibration ◽  
Residual Tensile Stress ◽  
Ceramic Surface ◽  
Composite Ceramics ◽  
Surface Residual Stress ◽  
Nano Composite ◽  
Ultrasonic Grinding ◽  
Grinding Conditions

The surface residual stress of nano-composite ceramics prepared by mixed coherence system and machined both in ordinary grinding(OG) and ultrasonic vibration grinding(TDUVG) respectively were described. Researches showed that the characteristics of residual stress on ceramic surface is affected by grinding load, ultrasonic vibration frequency and released stress induced by generation of cracks whose magnitude is affected by material removal mechanism. Whether in ordinary grinding or ultrasonic grinding, tangential residual stress (TRS) in X direction is tensile stress, and in Y direction is compressive stress. The surface residual tensile stress in ordinary grinding is larger than that in ultrasonic grinding with the same grinding conditions. The influences of multi-frequency on the residual stress are studied.

Fatigue Life Variance Prediction Incorporating Residual Stress Scatter Induced by Super-Finishing Grinding Process

2009 ◽  
Vol 416 ◽  
pp. 45-50
Author(s):  
Guang Hui Lu ◽  
Xue Ping Zhang ◽  
Er Wei Gao
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Diffraction Method ◽  
Machining Process ◽  
Stress Distributions ◽  
X Ray Diffraction ◽  
Machining Processes ◽  
Surface Residual Stress ◽  
Bearing Rings ◽  
The Impact

It is well known that there is a lager deviation in the fatigue life of machined components even under nominally identical loading conditions. Understanding and controlling fatigue life variance are essential to enhance reliability. However, few research focus on the impact of machining processes on the fatigue life variance of machined components. In this study, surface residual stress distributions of bearing rings randomly selected from a production line by super-finishing grinding, are measured by X-ray diffraction method in cutting and feed direction, and its scatter is analyzed by statistical tools. Based on the variance prediction theories, build a simplified fatigue life variance prediction model incorporating the resultant residual stresses scatter induced by machining process. Based on the Basquin equation, the model is validated by experimental data published in literature. The predicted fatigue life agrees well with the experimental average fatigue life. Statistical analysis shows that the predicted variances of fatigue life are equal to those estimated from experimental fatigue life.

Coupled Thermal-Mechanical Analysis of CO2 Laser Irradiation on Fused Silica

2016 ◽  
Vol 1136 ◽  
pp. 531-536
Author(s):  
Run Qiang Li ◽  
Peng Yao ◽  
Hao Meng ◽  
Jun Wang ◽  
Ke Zhang ◽  
...  
Keyword(s):  
Residual Stress ◽  
Tensile Stress ◽  
Laser Irradiation ◽  
Laser Energy ◽  
Viscoelastic Behavior ◽  
Mechanical Analysis ◽  
Fused Silica ◽  
Depth Of Cut ◽  
Residual Tensile Stress ◽  
Thermally Induced

To grind fused silica in ductile mode, it was proposed to repair surface and subsurface micro cracks of fused silica by CO2 laser irradiation. However, excessive residual stress remains on the surface because the melt fused silica on the surface quenches in air. It causes the critical depth of cut for ductile grinding fused silica to be smaller than 0.2μm. To investigate the distribution of the residual stress and look for an optimal manner of irradiation to control residual tensile stress, a numerical model of was built for simulating the dynamic behavior of fused silica when irradiated by CO2 laser. Laser energy absorption, heat transmission, viscoelastic behavior of fused silica and thermally induced stress were considered in the numerical simulation. The results show how the residual stress is formed and distributed. We found that an appropriate control of the temperature field as a function of time and position in the laser process is the key to reduce the residual stress. Therefore, three kinds of processes were proposed to reduce residual tensile stress on the surface of fused silica introduced by laser irradiation. The residual stress distributions of these three processes were compared by numerical analysis to decide a better method of laser irradiation.

Test Research on the Surface Residual Stress of Dimensional Ultrasonic Vibration Grinding for Al2O3/ZrO2(n)

2011 ◽  
Vol 295-297 ◽  
pp. 78-82
Author(s):  
Yan Wu ◽  
Er Geng Zhang ◽  
Wen Zhong Nie
Keyword(s):  
Residual Stress ◽  
Tensile Stress ◽  
Ultrasonic Vibration ◽  
Ground Surface ◽  
Ductile Deformation ◽  
Grinding Wheel ◽  
Ceramic Surface ◽  
Two Dimensional ◽  
Surface Residual Stress ◽  
Xrd Diffraction

Based on the research for the structure of the ceramic nanocomposites’ intragranular for Al2O3/ZrO2(n)，we did the test by the workpiece two-dimensional vibration grinding(WTDUVG), and focus on analyzing the characteristic and the effect element of the two-dimensional ultrasonic vibration grinding ceramic surface residual stress by the XRD diffraction. The result show that ceramic dimensional ultrasonic vibration grinding surface tensile stress is less than the same conventional grinding (CG) surface under tensile stress; two-dimensional ultrasonic vibration grinding surface residual compressive stress than conventional ground surface residual stress under the same grinding. Material removal mechanism of the grinding nature of the surface residual stress, when the material removaled by ductile deformation, grinding surface equal residual stress; when the material removaled by brittle- ductile mixed mode, the grinding surface tensile stress reduced, because the fracture of the ground surface, tensile stress released. As a results, the grit size of grinding wheel, Grinding depth and workpiece mechanical properties are the main technology factors affected the nature and size of the residual stress of ground surface.

Residual Stress Distribution in Pure Bending Beam Subjected to Tensile Failure on One Side

2006 ◽  
Vol 524-525 ◽  
pp. 253-258
Author(s):  
X.B. Wang
Keyword(s):  
Residual Stress ◽  
Tensile Strength ◽  
Stress Distribution ◽  
Tensile Stress ◽  
Strain Localization ◽  
Tensile Strain ◽  
Residual Stress Distribution ◽  
Neutral Axis ◽  
Residual Tensile Stress ◽  
Pure Bending

The stress distribution on the midsection of a pure bending beam where tensile strain localization band initiates on the tensile side of the beam and propagates within the beam is analyzed. Using the static equilibrium condition on the section of the midspan of the beam and the assumption of plane section as well as the linear softening constitutive relation beyond the tensile strength, the expressions for the length of tensile strain localization band and the distance from the tip of the band to the neutral axis are derived. After superimposing a linear unloading stress distribution over the initial stress distribution, the residual stress distribution on the midsection of the beam is investigated. In the process of strain localization band’s propagation, strain-softening behavior of the band occurs and neutral axis will shift. When the unloading moment is lower, the length of tensile strain localization band remains a constant since the stress on the base side of the beam is tensile stress. While, for larger unloading moment, with an increase of unloading moment, the length of tensile strain localization band decreases and the distance from the initial neutral axis to the unloading neutral axis increases. The neutral axis of midsection of the beam will shift in the unloading process. The present analysis is applicable to some metal materials and many quasi-brittle geomaterials (rocks and concrete, etc) in which tensile strength is lower than compressive strength. The present investigation is limited to the case of no real crack. Moreover, the present investigation is limited to the case that the length of strain localization band before unloading is less than half of depth of the beam. Otherwise, the residual tensile stress above the elastic neutral axis will be greater than the tensile strength, leading to the further development of tensile strain localization band in the unloading process.

Study on Pre-Stress Cutting of Bearing Race and Its Machined Surface State

2006 ◽  
Vol 532-533 ◽  
pp. 528-531 ◽  
Author(s):  
Bang Yan Ye ◽  
Bo Wu ◽  
Jian Ping Liu ◽  
Xiao Chu Liu ◽  
Xue Zhi Zhao
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Compressive Stress ◽  
Contact Fatigue ◽  
Residual Compressive Stress ◽  
Residual Tensile Stress ◽  
Machined Surface ◽  
Residual Stress State ◽  
Bearing Race ◽  
Hard Cutting

Theoretical analysis and experiments on bearing race show that a suitable residual compressive stress on roll path of bearing race can prolong its contact fatigue life. However, residual tensile stress is often found on workpiece surface of bearing race. To actively control the residual stress state and improve fatigue life of bearing part, a new method of pre-stress hard cutting is applied. In this paper, the principle of pre-stress hard cutting for bearing race is introduced as well as the experiments on it. In the experiments, residual stress, hardness and roughness of machined surface are measured and analyzed. Moreover, micro-topography and texture characteristics of machined surface are investigated and experimental results are compared with that by grinding. It is found that we can get residual compressive stress and fine quality on machined surface of bearing race by pre-stress hard cutting and increase its productivity as well.

Application of Outer Surface Irradiated Laser Stress Improvement Process (L-SIP) to Pressurizer as Residual Stress Improvement Method for Alloy 600 PWSCC Mitigation

2008 ◽  
Author(s):  
Takeshi Ueda ◽  
Koji Okimura ◽  
Kazuhiro Wakabayashi ◽  
Takashi Akaba ◽  
Kazuhiko Kamo ◽  
...  
Keyword(s):  
Residual Stress ◽  
Tensile Stress ◽  
Outer Surface ◽  
Alloy 600 ◽  
Surface Residual Stress ◽  
Steel Pipes ◽  
Inner Surface ◽  
Improvement Process ◽  
Improvement Method ◽  
Work Method

Improvement of residual stress is effective in a countermeasure to deal with the stress corrosion cracks in pipe welds. A irradiated laser stress improvement process (L-SIP) will be introduced as a method to improve residual stress inside steel pipes. This work method is to improve inner surface residual stress from tensile stress to compressive stress by irradiating laser beam around the welds of steel pipe and utilizing the temperature differences between inner and outer surface. Recently this method is applied to PWR pressurizer surge nozzle on TRUGA unit 2.

Further Research Into Wheel Rim Axial Residual Stress and Vertical Split Rim Failures

2012 ◽  
Author(s):  
Cameron Lonsdale ◽  
John Oliver
Keyword(s):  
Residual Stress ◽  
Tensile Stress ◽  
Stress Profile ◽  
Residual Tensile Stress ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wheel Rim ◽  
Axial Tensile ◽  
Axial Residual Stress ◽  
Class C

Recent work using x-ray diffraction techniques has shown that the axial residual stress pattern within the railroad wheel rim is significantly different for as-manufactured AAR Class C wheels vs. AAR Class C wheels that have failed due to a vertical split rim (VSR), and non-failed AAR Class C wheels that have been operating in service. VSRs almost always begin at areas of tread damage, resulting from shelling or spalling, and cracking propagates into the rim section under load. At the locations tested, the as-manufactured wheels have a relatively “flat” axial residual stress profile, compressive but near neutral, caused by the rim quenching operation, while wheels that have been in service have a layer of high axial compressive stress at the tread surface, and a balancing zone of axial tensile stress underneath. The magnitude and direction of this tensile stress is consistent with the crack propagation of a VSR failure. When cracks from the tread surface propagate into this sub-surface axial tensile zone, a VSR can occur under sufficient additional service loading, such as loads caused by in-service wheel/rail impacts from tread damage. Further, softer Class U wheels, removed from service and tested, were found to have a balancing axial tensile stress layer that is deeper below the tread surface than that found in used Class C wheels. This paper describes further efforts to characterize the axial residual stress present in failed VSR and used Class C wheels. Axial residual stress results are obtained near the initiation point of several VSR wheels using x-ray diffraction. Sub-surface axial residual stress patterns are also determined at points of high out-of-roundness for a group of wheels that were tested for TIR (total indicated runout) on the tread surface. Residual stress data and a photo are presented for a wheel rim slice containing a second VSR crack. Additionally, wheel rim ultrasonic testing data, collected by the wheel manufacturer when the wheels were new, are discussed for wheels that have failed due to VSRs and these data are compared to ultrasonic data for non-VSR wheels. Chemistry data are also compared. These data show that the driving force for VSRs is axial residual tensile stress, not a material cleanliness issue.

Investigation on Machined Surface Quality During Cutting of GH4169 Under High-Pressure Cooling

2020 ◽  
Vol 12 (7) ◽  
pp. 994-1003
Author(s):  
Ming-Yang Wu ◽  
Wei-Xu Chu ◽  
Ke-Ke Liu ◽  
Shu-Jie Wu ◽  
Yao-Nan Cheng
Keyword(s):  
Residual Stress ◽  
Plastic Deformation ◽  
High Pressure ◽  
Tensile Stress ◽  
Surface Quality ◽  
Work Hardening ◽  
Surface Plastic ◽  
Residual Tensile Stress ◽  
Machined Surface ◽  
Machined Surface Quality

The aerospace component material GH4169 has low thermal conductivity and poor machinability, resulting in difficulty to guarantee good surface quality after conventional cutting. High-pressure cooling assisted machining technology can effectively improve the problem. In order to study the effect of high-pressure cooling assisted processing technology on the machined surface quality of GH4169, in this paper, Deform-3D was first used to construct a thermo-mechanical coupling finite element model for turning GH4169 under high-pressure cooling conditions, to analyze the turning temperature and surface residual stress. Then, analysis was carried out on the residual stress, work hardening behavior, and metamorphic layer of the GH4169 machined surface, in combination with the turning experiment. The results show that, under the conditions of little feeding and highspeed cutting, the GH4169 turning surface generates residual tensile stress along with both the feeding and turning directions. Moreover, the residual tensile stress gradually turns into the residual compressive stress along the depth direction. The application of high-pressure coolant can reduce the residual tensile stress of the machined surface. As the cooling pressure increases, the residual tensile stress of the machined surface decreases. The coupling effect between thermal deformation and plastic deformation when turning GH4169 can cause the work hardening of the surface, and the hardening degree decreases with the increase of cooling pressure. The high-pressure cooling assisted machining technology can effectively reduce surface plastic deformation, and promote the lessening of grain refinement degree of the material surface, thereby reducing the thickness of the metamorphic layer.

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