交流电磁场检测技术(alternating current field measurement, ACFM)以其检测效率高、对表面裂纹响应灵敏、非接触等特性被广泛应用于钢轨表面滚动接触疲劳(rolling contact fatigue, RCF)裂纹的检测。利用COMSOL Multiphysics软件建立...交流电磁场检测技术(alternating current field measurement, ACFM)以其检测效率高、对表面裂纹响应灵敏、非接触等特性被广泛应用于钢轨表面滚动接触疲劳(rolling contact fatigue, RCF)裂纹的检测。利用COMSOL Multiphysics软件建立三维交流电磁场仿真模型,采用有限元的方法研究不同垂直角度的非均匀裂纹簇对ACFM信号的影响,研究表明,相较于均匀裂纹簇,不同垂直角度的非均匀裂纹簇的Bx特征曲线的波谷位置出现偏移,在此基础上研究了非均匀裂纹簇1~5 mm口袋深度、6~20 mm表面长度、5~15 mm裂纹间距对Bx信号的影响。展开更多
This paper investigates the rolling contact fatigue of kiln wheels with respect to the axis line deflection, which is linear with the applied supporting loads on wheels. Fatigue crack initiation criteria for elastic s...This paper investigates the rolling contact fatigue of kiln wheels with respect to the axis line deflection, which is linear with the applied supporting loads on wheels. Fatigue crack initiation criteria for elastic shakedown, plastic shakedown and ratcheting material responses are applied to assess wheels responses with two sets of axial line deflection. The finite element simulations are performed by using the bilinear material mode for nonlinear and kinematic hardening in ANSYS 11.0. By comparing the results from different critera, it is showed that the low-cycle fatigue is the predominated failure. Results from different axial line deflections indicate that the optimum adjustment can greatly enhance the whole life of the supporting structure.展开更多
This paper theoretically investigates the effects of stick-slip in roiling contact zone on stress intensity factors （SIFs） for sub- surface short cracks. New mathematical models for SIFs including stick-slip ratio a...This paper theoretically investigates the effects of stick-slip in roiling contact zone on stress intensity factors （SIFs） for sub- surface short cracks. New mathematical models for SIFs including stick-slip ratio are deduced in two cases. One is a subsur- face short crack parallel to surface, and the numerical analysis shows that the value of Kn increases with the increase of stick-slip ratio; the other is a subsurface short crack perpendicular to the surface, and the numerical analysis indicates that the positive value of KI decreases with the increase of stick-slip ratio. As AKI and AKI are necessary to evaluate the fa- tigue crack propagation rate or fatigue lifetime, the influences of stick-slip ratio on them are then discussed. It is found that the maximum variations of AK1 and AKu are both around 3.0% due to stick-slip ratio variation.展开更多
The influences of subsurface cracks,distributing along the axial direction,on the rolling contact fatigue(RCF)faliure in a bearing ring are investigated.A realistic three-dimensional model of the bearing ring containi...The influences of subsurface cracks,distributing along the axial direction,on the rolling contact fatigue(RCF)faliure in a bearing ring are investigated.A realistic three-dimensional model of the bearing ring containing three subsurface cracks is used to evaluate the fatigue crack propagation based on stress intensity factor(SIF)calculations.Moreover,the distributions of the subsurface cracks along the axial direction are varied to study their effects on RCF.The results provide valuable guidelines for enhanced understanding of RCF in bearings.展开更多
基金supported by the National Natural Science Foundation of China(No.51075140)Scientific Research Fund of Hunan Provincial Education Department(No.09C407)
文摘This paper investigates the rolling contact fatigue of kiln wheels with respect to the axis line deflection, which is linear with the applied supporting loads on wheels. Fatigue crack initiation criteria for elastic shakedown, plastic shakedown and ratcheting material responses are applied to assess wheels responses with two sets of axial line deflection. The finite element simulations are performed by using the bilinear material mode for nonlinear and kinematic hardening in ANSYS 11.0. By comparing the results from different critera, it is showed that the low-cycle fatigue is the predominated failure. Results from different axial line deflections indicate that the optimum adjustment can greatly enhance the whole life of the supporting structure.
基金supported by the National Science and Technology Supporting Program(Grant No.2011BAF09B01)
文摘This paper theoretically investigates the effects of stick-slip in roiling contact zone on stress intensity factors （SIFs） for sub- surface short cracks. New mathematical models for SIFs including stick-slip ratio are deduced in two cases. One is a subsur- face short crack parallel to surface, and the numerical analysis shows that the value of Kn increases with the increase of stick-slip ratio; the other is a subsurface short crack perpendicular to the surface, and the numerical analysis indicates that the positive value of KI decreases with the increase of stick-slip ratio. As AKI and AKI are necessary to evaluate the fa- tigue crack propagation rate or fatigue lifetime, the influences of stick-slip ratio on them are then discussed. It is found that the maximum variations of AK1 and AKu are both around 3.0% due to stick-slip ratio variation.
基金supported by the National Basic Research Program of China(Grant No.2011CB706605)State Key Program of National Natural Science Foundation of China(Grant No.51135007)+1 种基金Innovative Research Groups of the National Natural Science Foundation of Hubei Province(Grant No.2011CDA12)the Fundamental Research Funds for the Central Universities(Grant Nos.2012-Ia-017,2013-IV-014)for the support given to this research
文摘The influences of subsurface cracks,distributing along the axial direction,on the rolling contact fatigue(RCF)faliure in a bearing ring are investigated.A realistic three-dimensional model of the bearing ring containing three subsurface cracks is used to evaluate the fatigue crack propagation based on stress intensity factor(SIF)calculations.Moreover,the distributions of the subsurface cracks along the axial direction are varied to study their effects on RCF.The results provide valuable guidelines for enhanced understanding of RCF in bearings.
