基于真实几何特征的碎石道砟颗粒形态重构

Reconstruction of Particle Shape of Railway Ballast Based on Real Geometric Characteristics

碎石道砟颗粒的几何形态特征是影响散粒体道床物理力学性质的重要因素之一,对其颗粒形态特征的合理描述是研究道床力学行为以及揭示道床劣化机理的关键。利用平面图形分析法提取道砟的轮廓特征,通过快速傅里叶变换和响应面法建立道砟几何尺寸与傅里叶描述符之间的映射关系,提出基于真实几何特征的碎石道砟颗粒形态重构方法,并引入相似度指标评估重构道砟颗粒形态的准确性。研究结果表明:道砟长度、最小外接圆半径和最大内切圆半径对傅里叶描述符D 2、D 3、D 8有显著影响,可以采用这些指标建立响应关系;基于真实几何特征的碎石道砟颗粒形态重构法可以较好地反映轮廓的细节特征,通过该方法得到的道砟颗粒形态与真实道砟颗粒形态的平均相似度在95%以上。

The geometric characteristics of ballast particles are one of the most important factors affecting the physical and mechanical properties of granular track bed.The reasonable description of ballast particle morphology is the key to studying the mechanical behavior and revealing the deterioration mechanism of the track bed.The mapping relationship between the geometric size of the ballast and the Fourier descriptors was established by using the fast Fourier transform and the response surface method based on the contour characteristics of the ballast extracted by the plane graph analysis method.The reconstruction method for crushed stone ballast particle morphology was proposed based on the real geometric characteristics,while the similarity index was introduced to evaluate the accuracy of the reconstructed ballast particle morphology.The results show that the length of ballast,the minimum circumcircle radius and the maximum inscribed circle radius have significant indigenous effects on Fourier descriptors D 2,D 3 and D 8,and these indexes can be used to establish the response relationship.The shape reconstruction of crushed stone ballast particles based on real geometric characteristics can better reflect the details of the outline.The average similarity between the ballast particle shape obtained by this method and the real ballast particle shape is more than 95%.