Dissertação
Criação de um bloco virtual padrão de cargas para avaliação de fadiga do veículo, isodano com provas experimentais de durabilidade para chassis e carrocerias
Fecha
2019-12-12Autor
Marco Túlio Batista dos Anjos
Institución
Resumen
This work aims to propose a virtual fatigue block, which consists of virtual tracks and
maneuvers and their respective repetitions, standardized, for designing chassis
components and bodies in the virtual phases. Using four projects already consolidated,
their respective vRLDA (Finite Element based) models were built to provide loads in
time histories. In addition, virtual tracks and maneuvers were used which best represent
the experimental bench fatigue tests and the LDS which assess the durability of chassis
and bodies respectively. From the Level Crossings graphs resulting from the virtual
time histories, the resulting wheel center loads in the three main directions of the
vehicle from the virtual tracks and static maneuvers with the loads predicted in the
experimental tests were compared. After validating the virtual models' way of passing,
regarding speed and pathways, a number of repetitions for these pathways and virtual
static maneuvers were elaborated so that the virtual accumulated damage was
considered equivalent to those predicted in the experimental tests according to the
adopted criterion. Comparison results of virtual vertical and longitudinal load
magnitudes when compared with LDS results and longitudinal bench tests show
considerable discrepancies due to PotHole. However, such discrepancies were
considered acceptable, mainly because LDS also results in noticeably shifting loads (as
discussed in Annex A). For lateral loads, there were no differences like the other two
previous directions. Finally, calculated the number of repetitions for each static
maneuver and virtual track, with the equivalent damage criterion adopted, the
accumulated of the virtual fatigue schedule proposed respected the criterion intervals
after being properly adjusted and thus considered viable for virtual durability vehicle
evaluation.