更高速下轮轨瞬态“滚-滑-跳”接触行为及中/短波不平顺临界限值研究

On Transient Wheel-Rail Rolling-Sliding-Jumping Contact and Critical Sizes of Short/Medium-wave Irregularities at Higher Speeds

简述轮轨滚动接触行为预测方法现状的基础上,选择最适于400 km/h及以上更高速和中/短波不平顺激励下轮轨“滚-滑-跳”接触行为分析的瞬态滚动接触显式有限元建模方法,建立更高速轮轨三维瞬态滚动接触时域分析模型,数值模拟了轮对在典型曲线轨道上的瞬态曲线通过行为。根据现营高速轮轨的中/短波不平顺调研,以波长30~210 mm钢轨波磨为典型不平顺,考虑波磨激励下左右两侧轮轨动力作用相互影响,分析波磨几何等因素对速度500 km/h及以下轮轨瞬态“滚-滑-跳”接触行为的影响。考虑低、中频动力减载等因素的前提下,仅从轮轨接触脱离角度,提出轮轨中/短波不平顺的临界管理限值建议,讨论其重要性、合理性和应用局限,并与《高速铁路钢轨打磨管理办法》规定的波磨整治限度进行对比。

A review of prediction methods for wheel-rail rolling contact was first presented.It is found that the 3-D transient rolling contact model developed using the explicit finite element method seems to be the most suitable approach for analyses of transient wheel-rail rolling-sliding-jumping contact at 400 km/h,or at higher speeds,and in the presence of short/medium-wave irregularities.Therefore,a transient rolling contact model was developed to simulate the dynamic curving of a wheelset on a typical curved track in the time domain.Harmonic or ideal rail corrugation was taken as the typical short/medium-wave irregularity to study its influences on transient rolling-sliding-jumping contact,with a wavelength range of 30~210 mm considered on the basis of field observations of high-speed wheels and rails in operation.Besides corrugation geometry,corrugation occurring on the high and/or the low rails was also taken into account properly,with the speed up to 500 km/h.Considering dynamic unloading caused by dynamics of low and medium frequency,the critical sizes of short/medium-wave irregularities were determined,at which the wheel-rail contact loss just occurred.Finally,proposals for management of wheel-rail short/medium-wave irregularities were discussed from the aspects of importance,rationality and application limitations,and compared with the corrugation limit recommended for rail grinding operations in Management Measures of High-speed Railway Rail Grinding.