Research of Dynamic Constitutive Model of Reinforced Concrete Based on LS-DYNA
Bridge structure in life span, in addition to the need to withstand permanent and variable action, there may be large or small under dynamic loading, such as impact, explosion, earthquake etc. In order to get the real response of the structure under dynamic load, based on reasonable dynamic constitutive model, a nonlinear finite element analysis is needed. In this paper, several commonly used models of concrete dynamic constitutive model for ship collision with bridges are introduced: Reinforced concrete damage model (RC damage model), Elastic-Plastic Cap model, HJC model and Elastic model. Then the simulation analysis of two impact tests of rigid beads strike the target concrete walls and hammer strike the RC beams are carried out by using the analysis software LS-DYNA for nonlinear dynamic analysis. In the analysis, the influence of the various dynamic constitutive models on the impact structure is compared, and the calculated dynamic impact force-time curve and displacement-time curve are compared with the experimental data. It is found that the RC damage model can better simulate the change of concrete damage, and can simulate the development of structural cracks more realistic, and can consider the influence of reinforcement ratio on the impact force. Based on this, a multi parameter sensitivity analysis is made on the RC damage constitutive relationship, and the practical formula of the impact force is put forward. Research shows that the maximum impact force increases with the increase of the ratio of reinforcement, and the impact of the ship bridge collision analysis should be considered.