Finite Element Analysis Of Impact Between Heavy Vehicle And Semi-rigid Guardrail

Guardrail is an important facility for traffic safety, while semi-rigid guardrail is one of the most popular kind of guardrail used at world wide nowdays. The impact between vehicle and guardrail is very complicated. The vehicle and guardrail are two indiscerptible parts of the impactive system, which couple and affect each other and make up of an organic whole. In this thesis, relating to semi-rigid guardrail of the East Ocean Bridge and heavy container truck, some research on the kinematic rules of heavy vehicle and the extent of impactive damage were done. The main aspects are as follows:In the first, some relevant problems during the impactive process between truck and guardrail are analysed in detail, and finite element methods, especially the methods of impactive kinetics, which started with geometrical non-linearity, material non-linearity and contactical non-linearity were discussed also.Secondly, a finite element calculational and analytic model for the whole "vehicle-guardrail" impactive system was established, which can change material capability, structural dimension and impactive conditions by adjusting parameters. In this model, the large distorted phenomenon of semi-rigid guardrail and vehicle was taken into account, all contact parts was subdivided, a new turning set was introduced to simulate the connection between tractor and trailer, the rolling and brake of cartwheel was considered, and the influence of friction was thought over.Finally, by adjusting initial impactive conditions during the impactive process, three kinds of calculational cases were considered to analyse the kinematic rules of vehicle and the extent of impactive damage of guardrail system. By analysing the moving gesture, displacement, velocity and energy of veicle and the displacement, stress and strain of guardrail system, the thesis summarized the kinematic rules of vehicle and the extent of impactive damage of guardrail system for the three kinds of calculational cases, and provided some thoughts for the future.