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

Technical and environmental potentialities of recycled steel fiber reinforced concrete for structural applications

“…The IA approach proposed by Matos et al [31] was used to predict the fracture mode I parameters of RSFRC and ISFRC by using the experimental force-deflection relationships, Fδ, obtained in 3PNBBT (in this case δ can represent not only a deflection, but also a crack mouth opening displacement (CMOD) or a crack tip opening displacement (CTOD)) and RPT-3ps. The IA tool developed by Matos et al [31], whose corresponding software was named COFIT, includes two main modules: the Global fitting module (GFM) and the Parameter updating module (PUM). The GFM consists in a nonlinear least square fitting (NLSQ) algorithm that minimizes the error function: (1) where and are respectively the numerical and interpolated experimental forces at ith data point, and n is the number of numerical data points.…”

“…For a better and more efficient optimization process, COFIT allows the user to adopt different data point sampling density for a refining level according to the complexity of the experimental Fδ response. A detailed description of this IA is provided in [31].…”

Integrating Hybrid Reinforced Concrete Technology and Advanced FEM-Based Numerical Modelling for Crack Control in Long Concrete Foundations Without Joints

“…The inverse analysis was performed by conducting numerical simulations of the bending tests considering different sets of parameters that define the stress-crack width relationship of the FRC. The numerical simulations were conducted with the inverse analysis software COFIT, whose description can be found elsewhere [14].…”

Two-dimensional integrated mixed-mode smeared crack model for simulating FRC structures

“…In the context of the SCM approach, the mode I fracture behaviour of FRC is typically simulated using constitutive models based on exponential or multi-linear segment softening diagrams governed by input parameters that are usually determined by conducting inverse analysis (IA) of experimental results of 3PNBBT or round-panel tests (RPT) [18][19][20]. On the other hand, the shear behaviour is often accounted by means of a shear retention factor, which is frequently assumed constant or dependent on other entities involved in the fracture process [9,21,22], or alternatively by means of a shear softening diagram [23,24] where the parameters are, in general, difficult to estimate with confidence.…”

“…Furthermore, a set of modifications to the original fibre pullout models formulation is proposed in order to enhance the predictive performance of the MMFSCM. A multi-linear diagram, defined by a set of (w cr , 𝜎 𝑐𝑟 ) points is also implemented, since the use of an IA procedure in combination with such diagram type has been demonstrated to capture fracture mode I propagation in FRC exhibiting both strain softening and strain hardening behaviour [20]. The predictive performance of the MMFSCM is analysed and discussed by comparing numerical and experimental results gathered from the literature [17,44].…”