  Accidents that vehicles cross median and enter opposite lane happen
frequently, and the existing median barrier has weak anti-collision strength. A
new combined median barrier (NCMB) consisted of W-beam guardrail and concrete
structure was proposed to decrease deformation and enhance anti-collision
strength in this paper. However, there were some uncertainties in the initial
design of the NCMB. If the uncertainties were not considered in the design
process, the optimization objectives were especially sensitive to the small
fluctuation of the variables, and it might result in design failure. For this
purpose, the acceleration and deflection were taken as objectives; post
thickness, W-beam thickness and post spacing were chosen as design variables;
the velocity, mass of vehicle and the yield stress of barrier components were
taken as noise factors, a multi-objective robust optimization is carried out
for the NCMB based on Taguchi and grey relational analysis (GRA). The results
indicate that the acceleration and deflection after optimization are reduced by
47.3% and 76.7% respectively; Signal-to-noise ratio (SNR) of objectives after
optimization are increased, it greatly enhances the robustness of the NCMB. The
results demonstrate that the effectiveness of the methodology that based on
Taguchi method and grey relational analysis.
