Modeling of High-Strength FRC Structural Elements with Spatially Non-Uniform Fiber Volume Fraction

Abstract

The research presented in this paper has been motivated by the need to numerically simulate performance of high strength fiber reinforced concrete (HSFRC) structural elements with given spatially variable fiber volume fraction. The intended applications include prediction of load and deformation capacity of HSFRC members with imperfect fiber distribution or design and verification of functionally graded HSFRC members. In order to achieve a predictive capability, modeling is based on micromechanics of fiber debonding, pullout and crack-bridging. The concept of cohesive crack is employed for implementation in the finite element method (FEM). A strong emphasis is placed on the feasibility of the model identification. To this end, a procedure which uses data from conventional notched-beam fracture tests and inverse analysis to determine the model parameters is proposed. The model and the identification method are verified and validated both on micro and macro scales by comparing predicted results with experimental data.