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.

本文描述了一种新的反分析方法的开发，该方法利用三点缺口梁弯曲试验（3PNBBT）和在三点支撑下的圆板试验获得的实验数据来导出纤维增强混凝土（FRC）的断裂模式I参数。 （RPT-3PS）。该方法基于全局拟合策略，其中通过分析模型模拟数值响应，并通过修改控制FRC拉伸行为的变量来拟合实验结果。拟合过程依赖于有界多变量非线性最小二乘拟合算法，并基于数值和实验结果之间的力偏差误差，结合输入参数的自动更新过程。通过从文献中检索到的3PNBBT和RPT-3PS的实验结果来评估所提出方法的性能和预测潜力。此外，还通过评估输入变量在导出的裂缝参数中的初始猜测的影响来研究所实现方法的鲁棒性。最后，在分析实际比例的FRC梁的过程中应用了开发的工具，其中使用新提出的方法得出了I型断裂参数。