The aim of the research is a new safety road barrier made completely of wood. Road safety barriers usually are made of steel or concrete. Wood is a material with a complex structure, whose main features are anisotropy and hygroscopicity. It also possesses greatly different mechanics characteristics between the longitudinal direction and the tangential and radial direction. In Europe, road safety barriers have to pass crash tests required by EN1317 before their location. So in this research, a new type of barrier has been designed and modelled and has been simulated the impact with a vehicle using the software Ls-Dyna, which follows EN 1317 prescriptions. A parametric analysis has been conducted by the authors, to examine how humidity can modify mechanical characteristics of wood and so performance of the new barrier. The results appeared interesting: the new barrier satisfied all requirements prescribed by the Regulation and the parametric study highlighted that ASI (Acceleration Severity Index) index vary with the humidity but its values were always below the limit imposed by EN 1317.This study represents only one step of the research which needs more data to individuate a correlation between humidity and ASI index, and a real scale test to calibrate the model
Preliminary Results on a New Safety Road Barrier Made Completely of Wood.
MALTINTI, FRANCESCA;
2012-01-01
Abstract
The aim of the research is a new safety road barrier made completely of wood. Road safety barriers usually are made of steel or concrete. Wood is a material with a complex structure, whose main features are anisotropy and hygroscopicity. It also possesses greatly different mechanics characteristics between the longitudinal direction and the tangential and radial direction. In Europe, road safety barriers have to pass crash tests required by EN1317 before their location. So in this research, a new type of barrier has been designed and modelled and has been simulated the impact with a vehicle using the software Ls-Dyna, which follows EN 1317 prescriptions. A parametric analysis has been conducted by the authors, to examine how humidity can modify mechanical characteristics of wood and so performance of the new barrier. The results appeared interesting: the new barrier satisfied all requirements prescribed by the Regulation and the parametric study highlighted that ASI (Acceleration Severity Index) index vary with the humidity but its values were always below the limit imposed by EN 1317.This study represents only one step of the research which needs more data to individuate a correlation between humidity and ASI index, and a real scale test to calibrate the model
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