There are few recorded incidents of tyre explosion on large mining vehicles. It is a rare phenomenon that has predominantly occurred on haul trucks and has led to severe truck damage and fatalities. The aim of this report is to gain an improved understanding of tyre explosions on haul trucks, particularly the over-pressures that develop as a result of the shock waves propagating from the explosion.
The two main mechanisms for tyre explosion, pyrolysis and diffusion, are explained. The simple blast wave model of Vanderstraeten, Lefebvre and Berghmans (1995) is presented as a possible tool for modelling tyre explosion, and the basic behaviour of a three-dimensional explosion is discussed. The CFD software packages L1d and MB_CNS are evaluated as possible tools for modelling tyre explosion. Performance of the modelling tools is assessed by comparison with the results of numerical simulations published by Vanderstraeten, Lefebvre and Berghmans, and Liang, Wang and Chen (2002).
The three modelling tools were applied to the Channar catastrophic tyre incident (Cutler 2004) to estimate the peak pressures involved. More than 40 simulations were conducted, beginning with crude assumptions and refined and increased in complexity to incorporate additional aspects of the geometry.
It is found that L1d and the model of Vanderstraeten et al. are too simple to capture haul truck geometry adequately. Predicted over-pressures are sensitive to the initial conditions in the tyre, the size of the rupture area, and to model (and haul truck) geometry.
A simplified technique to model explosion of a truck tyre is presented. It utilizes MB_CNS in an axisymmetric capacity to predict over-pressure at any location on a haul truck following explosion. The model predicted an over-pressure in the range of 29 kPa to 65 kPa at the rear window of the driver’s cabin of the haul truck involved in the Channar incident.