车轮载荷对其残余应变应力分布特性的影响

Effect of Wheel Load on Distribution Characteristics of Residual Strain and Residual Stress of the Wheel

随着高速、重载铁路不断发展,轮轨滚动接触疲劳已成为影响和制约轮轨服役寿命和运输安全的重要因素,是轮轨的主要失效形式之一。滚动接触弹塑性应力应变分析是研究轮轨滚动接触疲劳失效的基础和关键。借助有限元软件ABAQUS,本文建立了车轮三维滚动接触弹塑性有限元模型,模型中材料本构关系采用Lemaitre-Chaboche非线性各向同性随动硬化循环塑性模型,通过在车轮接触表面反复施加移动法向载荷和切向载荷模拟轮轨滚动接触过程,得到了车轮接触表面附近的残余应力和残余应变。结果表明:随着载荷循环次数增加,车轮残余应力逐渐增大但很快趋于稳定,残余剪切应变也随之增大但增大速率逐渐衰减;纯滚动工况下最大接触压力越大,残余应力和残余应变越大,残余应力和残余应变最大值发生在车轮次表面;切向力对车轮接触表面附近的残余应力和应变影响明显,切向力作用下残余剪切应变最大值发生在滚动接触表面。

With the rapid development of high speed and heavy haul railway,rolling contact fatigue,an important factor that affects and restricts the wheel-rail service life and transportation safety,is one of the primary failure forms of the wheel-rail contact.Analysis of elastic-plastic stress and strain in rolling contact is the basis and key to study the fatigue failure of wheel-rail rolling contact. With finite element analysis software ABAQUS,a three-dimensional elastic-plastic finite element model for wheel-rail rolling contact was established,where Lemaitre-Chaboche nonlinear isotropic kinematic hardening cyclic plasticity model was applied to the constitutive relation of materials.The residual stress and the residual strain near the wheel contact surface were obtained by repeated application of the moving normal load and tangential load on the wheel contact surface to simulate wheel-rail rolling contact process.The results showed that,along with the increase of load cycles,the residual stress of the wheel was gradually increasing but soon became stable.The residual shear strain also increased but the increasing rate gradually attenuated.Under the rolling condition,the larger maximum contact pressure was,the greater residual stress and strain.The maximum residual stress and residual strain,respectively,occurred at the contact subsurface of wheel profile.The residual stress and residual strain were affected significantly by the tangential force.The maximum residual shear strain under the tangential force occurred at the rolling contact surface.