Study on the Designing Method of the Composite Materials Guardrail of Highway
|School||Wuhan University of Technology|
|Keywords||guardrail impact force structural transformation|
There are always some limits on the use of the present guardrail of highway. In recent years, with the emergence of new materials and technology and the increasing requirement of highway transportation safety, the improvement of highway guardrail and designing new types of guardrail have become one of the most important subjects in this area. In this paper, the international and domestic achievements of the guardrail of highway are summarized. Based on the present useful experiences,a method of designing the composite materials guardrail of highway is studied.A designing idea of structural transformation during the collision is put forward. We can make full use of the ability of absorbing energy when the high hardness resin is smashed into pieces, thus the strain energy accumulated during the earlier stage of the collision is sent out in the way of material essential failure, instead of the recovery of deformation as the other materials do. Then we can make sure that the vehicle out of control cannot affect the following vehicles. After the failure of the resin, the structure changes from beam to cable. With the fiber, we can ensure that the vehicle cannot rush out.Furthermore, a computing method of the impact force acting on the guardrail is proposed. There is a new feature during the collision that not only the form of the structure but also the stiffness is altered, which make the calculation of the impact force must also be changed.The property of composite materials guardrail is analyzed with the Finite Element Method (FEM).