Difference of Chord Offsets Method's Serviceability Analysis for Track Irregularities Representation
Research purposes:In the process of importing High-speed railway(HSR)construction technology,the difference of chord offsets(DoCOs)method was introduced in China Railway for representing profile/alignment irregularities.Nevertheless,there are some controversies about DoCOs'effects on track state evaluation and maintenance operation instruction,so DoCOs'serviceability in track maintenance should be ascertained.To address the underlying mechanism of this issue,this paper starts with the correlation between DoCOs and car body acceleration and evaluates DoCOs'reflection capability about vehicle dynamic response using correlation coefficient and normalized mutual information.Then in view of DoCOs'state space description,discusses track deformation representing capability of DoCOs and addresses the instruction capability for maintenance operation,which employed track deformation state-space representation and observability analysis.On this basis,compares track irregularities representing the capability of mid-chord offset(MCO)and difference of chord offsets.Research conclusions:(1)There is a weak correlation between 5 m/30 m or 150 m/300 m DoCOs and car body accelerations,and no evidence indicates that a nonlinear mapping structure exists.(2)Since the state space of 5 m/30 m or150 m/300 m DoCOs is not complete observable,it is difficult to instruct the maintenance from DoCOs.(3)MCO's unobservable states are quite a few compared with DoCOs'in the track deformation state-space representing,and it could be complete observable taking some supplementary observations,moreover,MCOs are strongly correlated with car body accelerations,all these characteristics are more propitious to evaluate the track states and instruct the maintenance operation.(4)These conclusions illuminate the serviceability problem of DoCOs existing in HSR track evaluation and maintenance and could present a theoretical foundation for selecting representation indices for track irregularities.
high-speed railwaytrack irregularitiesdifference of chord offsetcorrelationstate space description
万方数据
维普
