Effects of Load History and Design Variables on Performance Limit States of Circular Bridge Columns-Volume 3: Analysis Methods.

摘要

This report is the third of three volumes and presents the numerical portion of the research project on the impacts of loading history on the behavior of reinforced concrete bridge columns. Two independent finite element methods were utilized to accomplish the goal of this research work. First, fiber-based analysis was utilized which employed the Open System for Earthquake Engineering Simulation (OpenSees). The second model uses solid elements to predict bar buckling. The model included a segment of reinforcing bar and its surrounding elements, such as spiral turns and concrete. A series of strain histories from the experimental tests and fiber-based analyses were applied to the finite element model to study their impacts on the strain limit for reinforcing bar buckling.nInitial analytical investigations have shown significant impact of load history on the strain demand to lead to reinforcing bar buckling in the plastic hinge region. The parametric study extended the range of load history types and also studied the effect of reinforcement detailing on bar buckling. A design approach was developed to include the load history effect on the strain limit state of bar buckling.