CAJ | 학술논문

通过建立三维轮轨瞬态滚动接触有限元模型，研究带有踏面硌伤的车轮在指定牵引或制动力条件下的瞬态滚动接触行为，分析不同速度、硌伤几何和材料塑性变形对踏面硌伤处滚动接触行为的影响。结果表明：在60～300 km／h速度范围内，车轮硌伤所激起的接触力随速度的增加而降低；初期硌伤可能存在的边缘“堆起”能大大增加接触应力的水平，或可导致滚动接触疲劳的萌生；对于具有尖锐边缘的硌伤，弹塑性等效应力水平仍可明显大于车轮材料的强度极限，即可发生持续的塑性变形，易于萌生疲劳；相对而言，对于具有钝边缘的硌伤，相应的接触应力水平要低得多，车轮偏于安全。
통과건립삼유륜궤순태곤동접촉유한원모형，연구대유답면락상적차륜재지정견인혹제동력조건하적순태곤동접촉행위，분석불동속도、락상궤하화재료소성변형대답면락상처곤동접촉행위적영향。결과표명：재60～300 km／h속도범위내，차륜락상소격기적접촉력수속도적증가이강저；초기락상가능존재적변연“퇴기”능대대증가접촉응력적수평，혹가도치곤동접촉피로적맹생；대우구유첨예변연적락상，탄소성등효응력수평잉가명현대우차륜재료적강도겁한，즉가발생지속적소성변형，역우맹생피로；상대이언，대우구유둔변연적락상，상응적접촉응력수평요저득다，차륜편우안전。
A 3-D transient wheel/rail rolling contact model was set up by the explicit finite element method.The transi-ent rolling contact between the wheel and the rail was studied in the presence of wheel indentations and the traction or bra-king forces,and the influences of the rolling speed,indentation geometry and material plasticity on transient rolling contact of wheel indentations were analyzed.The results show that,in the speed range of 60~300 km/h,the dynamic force excited by the indentation is decreased with increasing the rolling speed.The pile-up of an indentation is found to greatly increase the stress level,which may initiate the rolling contact fatigue at a late stage.For those indentations with sharp pile-ups,the maximum Von Mises equivalent stress of elastic-plastic materials can still be much larger than the maximum tensile strength of wheel steel,and the continuous plastic deformation may occur to cause the rolling contact fatigue.In contrast, the stress level of an indentation with relatively blunt edges is much lower,and the wheel is probably safe.