ROLL-OVER RISK ASSESSMENT OF A FIRE TANKER IN UNEVEN FOREST TERRAIN

This paper presents the results of a study on the dynamic processes occurring in a fire truck tank with various water fill levels. The aim of the study is to obtain data on the fluctuation of the center of mass in the dynamic system formed by the water-filled tank of a fire truck moving across uneven forest terrain at different speeds. The obtained data make it possible to predict the risk of the fire truck overturning. To solve the problem, a mathematical model of the fire truck and its water tank was devel-oped using the LS-DYNA software package for dynamic system modeling. To simulate the dynamic effect of uneven forest terrain on the water tank, time-dependent angular displacements of the tank were determined. These angular values were used as boundary conditions to simulate the terrain’s dynamic impact. The tilt angles of the fire truck’s water tank were determined based on terrain ir-regularities, whose geometry was generated using a pseudorandom number generator. By applying the explicit method of integrating dynamic equations implemented in LS-DYNA, patterns of center of mass fluctuation of the water tank were identified depending on the fill level and vehicle speed. Based on the modeling results, a mathematical model was developed to deter-mine the optimal route of the fire truck to maintain its stability. Keywords: fire tanker, uneven forest terrain, center of mass fluctuation, smoothed particle hydrodynamics method, rollover risk, optimal route model.