Modeling Reinforced Concrete Stiffness
Part 1: Material BehaviorWe begin the series at the material level, exploring the stiffness of steel and concrete through their stress-strain behavior. What does E really mean when the material isn’t linear?
Part 2: Section StiffnessFrom gross section to tangent stiffness, we explore how different modeling assumptions affect EI in a reinforced concrete column—and why stiffness depends on load level.
Part 3: FEA Modeling – DeflectionsWe apply four different stiffness assumptions to a reinforced concrete column model in VisualAnalysis and compare the predicted deflections. See how nonlinear behavior affects results and how to incorporate tangent stiffness in FEA.
Part 4: Indeterminate Structures & Force DistributionExplore how non-linear concrete behavior impacts force distribution in indeterminate structures. We model a two-column frame and show how load-dependent stiffness reshapes the design moment — all with a virtual work twist.