Multi-objective optimization design of post-soil system for enhanced W-beam guardrail containment performance

Abstract

In the W-beam guardrail system, the post can provide sufficient lateral force through interaction with the subgrade and can create the necessary containment function by connecting with the W-beam rail panel. The purpose of this study is to evaluate the best embedment depth and section size of two different posts in the same subgrade from the perspectives of maximum lateral force and occupant ridedown acceleration for enhanced the containment performance of guardrail protection system in China. An accurate lateral force measurement method is used for the inertia effect in collision problems. And the exact finite element model of post-soil interaction is built by combining dynamic impact test with detailed finite element study. Then the Genetic algorithm (GA) was used to determine the optimum value of spread and then the GA-RBF was applied to construct the surrogate models of the analytical objective, which increased the accuracy of fitting. Finally, the embedment depth and structure size were obtained using multi-objective genetic algorithm. Full-scale crash test results show that the optimum design results meet the requirements. Through optimization design, W-beam guardrail has been greatly improved, which improves the crash safety of corrugated beam guardrail.