Fiber damage analysis model for RC beam-column based on EEP super-convergent computation

A new numerical strategy to model nonlinear damage behavior of RC beam-column member based on level of material and super-convergent computation is presented in this paper. A fiber damage analysis model (FDAM) for RC beam-column member is established by analyzing section of fiber beam column element with the uniaxial damage constitutive relations of concrete. The damage index of RC member through statistical analysis of concrete fibers damage is defined in the extreme section of beam elements, which can describe the nonlinear damage behavior of RC beam-column member under any loadings. The newly proposed element energy projection (EEP) method is applied to the inelastic analysis of FDAM. EEP super-convergent formulas for section forces and deformations of beam-column are established, and general algorithm and numerical strategy adopting EEP super-convergent computation for section deformation increment are proposed in the classical Newton-Raphson process. Both analysis and numerical test show that the EEP method can effectively find out the nonlinear feature of the distribution, and accurately obtain the damage distribution of RC beam-column. The proposed numerical scheme in this paper proves to be effective and convenient in its use and can be easily integrated into the present inelastic FEM programs of structure analysis.