ANALYSIS OF THE NONLINEAR DYNAMIC BEHAVIOUR OF REINFORCED CONCRETE BRIDGE BEAMS WITH VARIABLE REINFORCEMENT DISTRIBUTION THROUGH THE VEHICLE-BRIDGE INTERACTION AND THE DAMAGE MECHANICS

Ana Paula Imai¹; Roberto Dalledone Machado¹; Thiago de Oliveira Abeche¹; Marcos Arndt¹

¹ Federal University of Paraná (UFPR)

doi:10.20906/CPS/CILAMCE2017-1339

Resumo

The concrete's damaging process depends, among other factors, of its interaction with other materials. The applicability of the reinforced concrete is enabled by the proximity between the materials' thermal expansion coefficients, granting, this way, the adhesions and avoiding the bond-slip between the concrete and the steel bars. The beginning of the concrete's fissuration can, however, cause the loss of adhesion between the materials. The material's damaging evolution process depends not only of the stress state, but mainly from the accumulated strain state. Therefore, the distribution of the reinforcement along a bridge's beam highly influences the concrete's damage evolution. For highway and railway bridges' cases, the dynamic loads generated from the passage of vehicles on it can amplify the loss of integrity of the concrete and the strain hardening of the reinforcement. However, the normative codes for bridge's design allow to neglect the structure's dynamic effects, converting them into an equivalent increased static loading. Besides that, the codes suggest a linear elastic behaviour for the materials in the structural analysis. Nevertheless, this method doesn't consider the process of damaging and plastification of the concrete and the steel, respectively, neither the dynamic behaviour of the system. The consideration of the damage mechanics on the concrete and plasticity on the steel bars enhance the model complexity, transforming it in a nonlinear and dynamic problem, modifying the structural responses. Additionally, the consideration of a variable distribution of the reinforcement along the beam's length contributes to the analysis of more realistic models. Thus, this work seeks to evaluate the nonlinear dynamic responses of a reinforced concrete bridge through its dynamic interaction between a vehicular model, in which the reinforcement distribution affects the damage evolution. The beams are modelled trough finite elements method, using the ABXDNL 2.7 program and additional routines developed in C++

Palavras-chave: Nonlinear Dynamics; Reinforced Concrete Structures; Damage Mechanics; Dynamic Interaction; Nonlinear Finite Element Method