Modeling the compaction behavior of heavily loaded tires and rubber tracks

摘要

Ansorge and Godwin (2007'a and 2008a) showed a clear benefit of a rubber tracked undercarriage system compared to a wheeled undercarriage system. Following Ansorge and Godwin (2007 b) it was possible to predict the measured sinkage from tires using anin-situ virgin compression line (VCL). This work now focuses on the ability of the approach to describe the compaction behavior of tracks with respect to the sinkage. The comparisons of in-situ VCLs and the resulting soil displacement predictions showedthat the predictions for tires were best, if the in-situ approach for the derivation of a VCL from Ansorge and Godwin (2007b) was applied independently to tires. Adding track data to derive an in-situ VCL resulted in less accurate predictions. This is due to the fact that tracks show a different compaction behavior than tires. Most likely the relationship of major and minor principle stresses is different beneath tracks and tires leading to slightly differing VCLs. Moreover, this might be due to the strong backward soil shear caused by a track. This strong layer at the surface picked up by Ansorge and Godwin (2007a) and explained by Ansorge and Godwin (2008a) is probably able to support parts of the track without further compacting the underlying soil. Using a track specific in-situ VCL it was not possible to predict the rut depth of a track accurately as a multi-tire body. The soil displacement approaching zero fora track at 500 mm depth could not be predicted either. The rut depth caused by the track was most accurately predicted with the multi-tire body and a tire only in-situ VCL. Therefore it can be concluded that the sinkage of a track can be predicted using the tire approach, however, the accuracy of predicting the characteristic of soil displacement with depth is limited.