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

Abstract

A review of prediction methods for wheel-rail rolling contact was first prcsented. It is found that thc 3-D transient rolling contact model dcveloped using the explicit finite elemcnt 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. Harmonie 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 wave-length ränge of 30-210 mm considered on the basis of field observations of high-speed wheels and rails in Operation. Be-sides corrugation geometry, corrugation oecurring on the high and/or the low rails was also taken into aecount 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 oecurred. Fi-nally, proposals for management of wheel-rail short/medium-wave irregularities were discussed from the aspects of impor-tance, rationality and application limitations, and compared with the corrugation limit recommended for rail grinding Operations in Management Measures of High-speed Railway Rail Grinding.