摘要
目的针对发动机气缸套圆角在循环载荷下易发生疲劳断裂的问题,探究气缸套圆角在滚压强化工艺作用下的残余应力试验测试及数值模拟方法。方法基于X射线衍射原理,在PROTO-LXRD应力仪运用侧倾固定ψ法进行气缸套予圆角0°、90°、180°和270°四个方位取样测试,获得周向上残余应力值;构建气缸套-滚轮显式动力学有限元分析模型,分析气缸套圆角在滚轮滚压过程中的塑性变形及残余应力变化特性,探明滚轮端面半径、滚压圈数、滚压力和滚轮倾角等滚压工艺参数对残余应力的作用规律,揭示工艺参数对气缸套圆角残余应力的影响权重。结果气缸套圆角残余应力的试验测试和数值模拟结果的误差为4.96%;气缸套圆角区域的塑性应变随滚压圈数增加而累积,节点N4955的等效塑性应变在8圈滚压后达到0.067,相应的残余应力也逐渐增大,节点N4955的Min Principal应力达到‒255 MPa。此外,气缸套圆角残余压应力随着滚轮端面半径增加而减小,随着滚压圈数和滚压力的增加而增大,而随着滚轮倾角的增加呈先增加后减小的趋势,且平均梯度分别为57.92、‒16.20、‒357.28、‒35.00 MPa,滚压力相比其他滚压工艺参数对气缸套圆角残余应力的影响更大。结论针对气缸套圆角滚压工艺,提出了一种有效的残余应力测试和有限元仿真方法,揭示了工艺参数对圆角残余应力的作用规律及影响权重,可用于气缸套圆角滚压工艺的技术改进。
To address the fatigue fracture issue in engine cylinder liner fillets under cyclic loading,the work aims to investigate the effects of roller burnishing process parameters such as roller end face radius,number of rolling passes,rolling force and roller inclination angle on the residual stress distribution and quantify their effect weights.The methodology integrated experimental X-ray diffraction(XRD)measurements and explicit dynamic finite element analysis(FEA)to characterize residual stress evolution and plastic deformation during the roller burnishing process.Residual stress values along the circumferential direction of the cylinder liner fillet were experimentally measured with the side-inclination fixedψmethod on a PROTO-LXRD stress analyzer.Samples were extracted at 0°,90°,180°,and 270°orientations,with consistent measurement parameters(Cr-Kαradiation,30 kV voltage,1 mm collimator diameter).A high-fidelity finite element model was developed in Abaqus/Explicit,incorporating alloy gray cast iron(elastic modulus:138.5 GPa,compressive yield strength:538 MPa)for the cylinder liner and a rigid roller(HBW 670,E=207 GPa).Mass scaling(factor:10000)was applied to optimize computational efficiency without compromising accuracy.Plastic strain and minimum principal stress at node N4955 were analyzed to evaluate residual stress accumulation and distribution uniformity.Experimental results showed an average residual stress of‒242.35 MPa across four measurement points,with a simulated value of‒255 MPa at node N4955,yielding a relative error of 4.96%,which fell within the acceptable engineering tolerance(5%-10%).Parametric studies revealed distinct trends:residual stress decreased by 57.92 MPa/mm as the roller end radius increased from 1.8 mm to 2.1 mm due to reduced contact pressure,increased by‒16.20 MPa/pass with additional rolling passes(4-10 passes)owing to cumulative plastic strain,and surged by‒357.28 MPa/kN under higher rolling forces(10-18 kN)as deeper material deformation occurred.The residual stress peaked at‒288 MPa with a roller inclination angle of 45°,beyond which it declined(‒35.00 MPa/(°))due to misalignment-induced stress relaxation.Sensitivity analysis via normalized gradients identified rolling force as the dominant parameter(68%contribution),followed by roller radius(19%),inclination angle(9%),and rolling passes(4%).The accumulation of plastic strain in the fillet region correlated strongly with rolling passes.Node N4955 exhibited an equivalent plastic strain(PEEQ)of 0.067 after 8 passes,accompanied by a minimum principal stress of‒255 MPa.The compressive residual stress distribution became more uniform with increasing passes,enhancing fatigue resistance by mitigating stress concentration.The FEA model demonstrated robust accuracy which was validated by experimental data and provided insights into optimizing process parameters for industrial applications.For instance,increasing rolling force within the elastic limit of the material significantly elevated compressive residual stress,while adjusting the roller inclination angle to 45°maximized stress uniformity.This work establishes a systematic framework combining advanced XRD-based experimental techniques with dynamic explicit FEA for residual stress analysis in geometrically complex components.The quantified parameter effect hierarchy offers actionable guidance for refining roller burnishing processes in automotive manufacturing,particularly for high-cycle fatigue-critical components like cylinder liners.The methodology is extensible to other precision engineering applications requiring surface strengthening,such as aerospace bearings or medical implants,bridging the gap between theoretical research and industrial implementation.Future studies could be carried out to explore temperature effects during rolling or multi-pass optimization strategies to further enhance fatigue performance and process efficiency.
作者
朱正道
鲍珂
曹宝生
向建华
ZHU Zhengdao;BAO Ke;CAO Baosheng;XIANG Jianhua(School of Mechanical Engineering,Beijing Institute of Technology,Beijing 100081,China;China North Vehicle Research Institute,Beijing 100072,China)
出处
《表面技术》
北大核心
2025年第17期212-221,共10页
Surface Technology
关键词
气缸套
塑性变形
残余应力
试验测试
数值模拟
滚压工艺参数
cylinder liner
plastic deformation
residual stress
experimental test
numerical simulation
rolling process parameters
