Figure 8 shows the comparison betwe

Figure 8 shows the comparison between the timehistories of the WLR obtained from the four modelsin Table 1 and that by the TTISIM program. It can beseen that the WLR obtained from the fixed trackmodels (R0C and R0L) diverges significantly fromthat obtained by the TTISIM program. The movingoscillator track with linearized Hertz contact (R1L)and constraint wheel–track contact model (R1C) produce WLR almost identical to that obtained from theTTISIM program. These results show that the railvibration has significant effect on the wheel–rail force.Thus, the R0 model omitting the rail vibration fail toaccurately predict the wheel–rail force. As long as therail vibration is included, both wheel–rail contact models (R1C and R1L) can give reliable prediction of theWLR.