Energy dissipation analysis for inelastic reinforced concrete and steel beam-columns

Abstract Presented is a thermodynamics based methodology for computing energy dissipation in inelastic beam-column elements. Theoretical formulation for energy storage and dissipation in uniaxial steel fiber and concrete fiber models is derived from the principles of thermodynamics, in conjunction with a few assumptions on energy transformation and dissipation. Proposed methodology is implemented in Real-ESSI Simulator and illustrated through a number of numerical examples on beam-columns and frame models under various loading conditions. It is shown that the consideration of plastic free energy in addition to plastic work, is necessary to correctly evaluate energy dissipation in nonlinear beam-column elements. Results of energy analysis indicates that the difference between plastic work and plastic dissipation could be significant, and that the ratio between them evolves with time.