Comparison between an inverse analysis procedure results and experimental measurements obtained from UHPFRC four-point bending tests

Autores UPV
Año
CONGRESO Comparison between an inverse analysis procedure results and experimental measurements obtained from UHPFRC four-point bending tests

Abstract

Determination of the tensile properties of such a deflection hardening response material as UHPFRC is still a serious challenge for both researchers and designers. This process involves many factors, such as specimen size, fibre orientation or test typology. The so-called inverse analysis is used to obtain the tensile constitutive properties that are consistent with the specimen response in a bending test. This work presents an inverse analysis methodology developed to be applied over four-point bending tests. This procedure is based on a deflection to curvature transformation and on a point-by-point formulation. A set of UHPFRC specimens with different heights but with the same slenderness have been tested. The deflection to curvature transformation used as input for the inverse analysis procedure has been validated by its comparison to the experimental average curvature within the constant moment area. A clear scale-effect in the stress-strain relationship is derived from these tests after macro-crack starts growing. A strain-crack opening transformation as a function of the specimen height is proposed for four-point bending tests setup. It permits avoiding any size influence in the post-peak behaviour, showing that stress-crack opening relationship is not dependant on the specimen height.