Phase-field modeling of fracture in high performance concrete during low-cycle fatigue: Numerical calibration and experimental validation

Abstract

The development of an elasto-plastic phase-field model is presented which is able to predict nonlinear behavior of high performance concrete (HPC) during low-cycle fatigue. An elasto-plastic damage model which follows the Drucker–Prager yield criterion is formulated. For the modeling of unsymmetric tension–compression behavior of HPC two different continuous stepwise linearly approximated degradation functions for HPC in tension and in compression are used. The experimental three-point bending tests at low-cycle using notched beams of pure HPC are performed. Load–CMOD (crack mouth opening displacement) curves are plotted using the measured experimental data and residual stiffness–CMOD curves are calculated using these experimental Load–CMOD curves. The data used for the interpolation of degradation functions are calibrated using the experimental results for three-point bending tests. For that purpose the uniaxial tension and uniaxial compression tests and three-point bending beam test for HPC are simulated numerically. The accuracy of the proposed numerical model using the presented integration algorithm is verified by comparing the degradation of stiffness in numerical and experimental results.