In the present work, a multiscale model for fibre reinforced concrete (FRC) beams failing in bending is presented. At the microstructural level, the fibre is modelled as a one-dimensional continuum with axial, shear and bending deformability, with cohesive-like interfaces to simulate the interaction with the surrounding concrete. At the macroscopic level, the response of the beam is simulated by discretising the cross-section into layers and by enforcing the proper compatibility conditions between the layers. In the post-cracking stage, the tensile capacity is assured by the fracture energy of the concrete and the fibre resisting mechanisms simulated by the fibre pull-out constitutive laws determined at the microstructural level. The model can account for fibre distribution and orientation, controlled by the casting conditions and geometry of the mould. By using experimental data available from the open literature, it is proved that such an integrated approach is able to derive, by inverse analysis, the stress-crack width relationship of FRC, which is the fracture mode I information in the material nonlinear analysis of FRC structures with approaches based on the finite element method.

在目前的工作中，提出了一种弯曲失败的纤维增强混凝土（FRC）梁的多尺度模型。在微观结构水平上，将纤维建模为具有轴向，剪切和弯曲变形能力的一维连续体，并具有类似内聚力的界面来模拟与周围混凝土的相互作用。在宏观层面上，通过将横截面离散化为多层并在各层之间施加适当的相容性条件，可以模拟光束的响应。在后开裂阶段，混凝土的断裂能和通过在微观结构水平确定的纤维拉拔本构律模拟的纤维抵抗机制确保了抗拉能力。该模型可以说明纤维分布和方向，由铸模条件和模具几何形状控制。通过使用公开文献中提供的实验数据，证明了这种综合方法能够通过反分析得出FRC的应力-裂纹宽度关系，这是FRC的材料非线性分析中的断裂模式I信息。基于有限元方法的结构。