Design And Crashworthiness Study On Anti-vehicle-collision Composite Structure For Bridges

The design of anti-vehicle-collision for bridge in the specification of China generally reference requirement abroad.Recently,the requirement of anti-collision force in AASHTO had been increased,which has not been considered yet at the present code in China.It is necessary to adopt a reliable protection device to reduce the impact force of car.Fiber-reinforced composite materials have been widely used in the automotive and aerospace industry,since it has a less dense,high strength and corrosion-resistant characteristics,etc..Thus,the fiber-reinforced composite material with honeycombtype structure is studied for the anti-vehicle-collision structures.First,in consideration of the actual production process,numerical simulation method has been applied to study the crashworthiness of composite material plates with different paving modes,and obtains the design parameters: the basic paving method which has relatively better crashworthiness,and the layer thickness etc..According to the actual pier size,the material and the basic type of the bridge anti-vehicle-collision structure are initially determined,then,the nonlinear numerical simulation analysis is carried out,research shows that the designed structure has excellent crashworthiness.Then,the bridge anti-vehicle-collision structure is used as the research object,car-structure collision test scheme is designed and the test is carried out.The numerical simulation and experimental results are compared,including impact force,energy absorption unit mass and impact depth,etc.The results show that the simulation method has great reference value in the structure design process,although the experimental and simulation results have some differences under the influence of experimental conditions and production processes.At last,this paper redesigned the type of structure.Then,sensitivity analysis method is adopted to determine the significance of design variables about the structure crashworthiness,and reasonable sample space was designed by using uniform design experimentation,then nonlinear numerical simulation method and response surface method are adopted to obtain surrogate models about designvariables,impact force,energy absorption unit mass and impact depth.With matlab software and genetic algorithm method,more reasonable sizes of the structure are optimized.The results show that the optimized structure not only has excellent crashworthiness and meets pier design requirements,but also reduces crash costs.So,this structure can be widely used in engineering practice.