The possibility of simulating the lift-up of tires on cornering maneuvers on various vehicles with rollover propensities was investigated. This simulation was validated for different speeds and different payloads and center of gravity heights. In Europe, roundabouts are replacing traditional crossings, giving an important reduction of fatalities; although few cases of heavy vehicle rollover have been recorded, in spite of low velocity, due to the geometric features. This study is a contribution to the comprehension of this kind of accident. For ground test validation, a heavy truck of 10-tons payload was chosen, and instrumented with different sensors, and for safety reasons, equipped with stabilizers. The dynamic parameters of the input vehicle file of the simulating model were adjusted on basis of elementary longitudinal and transversal ground tests. The model used is a French society SERACD package called PROSPER V4, which gave accurate predictions, even in strong inputs. Two different trajectories were chosen: a circle and a roundabout trajectory rebuilt on the test track. Test parameters were different speeds and load cases, with changing center of gravity height. Measurements, digital video and GPS-trajectory were CD-recorded: from these data, the location of the beginning of wheel lift-up was precisely determined. This information was compared to the simulation. This is considered to be the main validation criterion. The next steps in the study will include other rollover-prone vehicles. The package will be then used as a tool to define safety load conditions and to determine rollover stability limits which would be communicated to drivers. For the covering abstract see ITRD E825082.
Abstract