基于灰色关联度的铁路道砟表面形态指标研究

Research on surface morphology index of railway ballast based on grey correlation degree

道砟作为直接承受铁路轨道荷载的材料,需要有较好的表面形态和抗磨耗能力.以新建铁路用一级碎石道砟为研究对象,通过洛杉矶磨耗试验改变道砟的表面形态,利用图像处理软件确定出面积、等效椭圆长轴长度、等效椭圆短轴长度、费雷特最大直径、费雷特最小直径、轴向系数、圆度和Angularity(P)8个表面形态指标;对不同磨耗次数下各评价指标的变化趋势和不同粒径的损失百分比进行分析,进一步结合灰色关联分析理论提出最优评价指标和具体要求.结果表明:各评价指标值都随着磨耗次数的增加逐渐减小,最终趋于稳定状态;16~25 mm与56~63 mm粒径的道砟在洛杉矶磨耗试验中最易被磨耗.结合灰色关联度计算结果,最后确定出Angularity(P)、轴向系数和圆度为道砟表面形态的最优评价指标.

As the material directly bearing the railway track load,ballast needs to have better surface morphology and wear resistance.The first-class crushed stone ballast for the new railway was taken as the research object,Los Angeles abrasion test was used to change the surface morphology of the ballast,and image processing software was used to determine eight surface morphology indexes:area,equivalent ellipse long axis length,equivalent ellipse short axis length,Ferret maximum diameter,Ferret minimum diameter,axial coefficient,roundness and Angularity(P).The change trend of each evaluation index and the loss percentage of different particle size under different abrasion times were analyzed,and the optimal evaluation index and specific requirements were further put forward in combination with the grey correlation analysis theory.The results show that the values of each evaluation index gradually decrease with the increase of abrasion times,and finally tend to be stable.16-25 mm and 56-63 mm size ballast are most easily worn in Los Angeles abrasion test.Combined with the results of grey correlation degree calculation,angularity(P),axial coefficient and roundness are determined as the optimal evaluation indexes of ballast surface morphology.