Model for Anchored Reinforcing Bars under Seismic Excitations

摘要

This study presents a finite element model for reinforcing bars anchored inconcrete and subjected to severe cyclic excitations. The solution to the problem of stress transfer between reinforcing steel and concrete is based on the flexibility method. In this case, the governing differential equations are solved by force interpolation functions that strictly satisfy equilibrium along the anchored reinforcing bar. This solution method results in a very robust and stable nonlinear algorithm, particularly for systems that exhibit severe stiffness and strength deterioration, as is the case for anchored reinforcing bars. In the systematic derivation of the proposed solution method, the model is viewed as a simple mechanical system that is comprised of two components in parallel. The first component is the reinforcing bar and the second is the interface between reinforcing steel and surrounding concrete. The nonlinear hysteretic behavior of the model derives entirely from the nonlinear constitutive behavior of these two components.