A new inverse analysis approach for predicting the fracture mode I parameters of fibre reinforced concrete

Abstract

This paper describes the development of a new inverse analysis approach to derive the fracture mode I parameters of fibre reinforced concrete (FRC) by using the experimental data obtained from three-point notched beam bending tests (3PNBBT) and round panel tests supported on three points (RPT-3PS). The approach is based on a global fitting strategy, in which the numerical response is simulated by means of analytical models, and fitted to the experimental results by modifying the variables that govern the tensile behaviour of FRC. The fitting procedure relies on a bounded multi-variable nonlinear least squares fitting algorithm, coupled with an automatic updating procedure of the input parameters based on the force deviation error between numerical and experimental results. The performance and predictive potential of the proposed approach are assessed by means of experimental results from 3PNBBT and RPT-3PS retrieved from the literature. Also, the robustness of the implemented methodology is also investigated by evaluating the impact of the initial guess of the input variables in the derived fracture parameters. Finally, the developed tool is applied within the context of the analysis of a real-scale FRC beam, where the mode I fracture parameters were derived using the newly proposed methodology.