Wang Jiaming, Jivkov Andrey P, Engelberg Dirk L, Li Qingming
Department of Mechanical, Aerospace and Civil Engineering, University of Manchester, Manchester M13 9PL, UK.
Materials Performance Centre, Department of Materials, University of Manchester, Manchester M13 9PL, UK.
Materials (Basel). 2022 Jan 18;15(3):704. doi: 10.3390/ma15030704.
Damage initiation and crack propagation in concrete are associated with localisation of energy dissipation by the concrete meso-structure. Meso-scale models are, therefore, required for realistic analysis of concrete non-linear behaviour. Such models are constructed either from X-ray Computed Tomography images (image-based modelling) or by in silico meso-structure generation (parametric modelling), while both approaches are widely used and their advantages and disadvantages are recognised, little work is done on comparing their performance in predicting measured macroscopic behaviour with equivalent constitutive relations for meso-structural features. This work uses microstructure characterisation and mechanical behaviour data to construct, validate and compare the two modelling approaches. The macroscopic behaviour obtained with both meso-structural models is found to be in good agreement with experimental data. Differences are observed only between the predicted distributions of damage within specimens. These outcomes suggest that the computationally simpler parametric meso-structures are sufficient to derive stress-strain behaviour for engineering-scale models in the absence of other environmental factors. The observed differences in damage distribution could be important for analysis of coupled behaviour, e.g., mass transport and chemical reactions affecting local mechanical properties and being affected by local damage. Establishing the importance of damage distribution is such cases requires further research.
混凝土中的损伤起始和裂纹扩展与混凝土细观结构的能量耗散局部化相关。因此，需要细观尺度模型来对混凝土的非线性行为进行实际分析。此类模型要么由X射线计算机断层扫描图像构建（基于图像的建模），要么通过计算机模拟细观结构生成（参数化建模），虽然这两种方法都被广泛使用且其优缺点已得到认可，但在比较它们在使用细观结构特征的等效本构关系预测实测宏观行为方面的性能方面，所做的工作很少。这项工作使用微观结构表征和力学行为数据来构建、验证和比较这两种建模方法。发现两种细观结构模型获得的宏观行为与实验数据吻合良好。仅在试件内部损伤的预测分布之间观察到差异。这些结果表明，在没有其他环境因素的情况下，计算上更简单的参数化细观结构足以得出工程尺度模型的应力-应变行为。观察到的损伤分布差异对于耦合行为的分析可能很重要，例如质量传输和化学反应影响局部力学性能并受局部损伤影响。在这种情况下确定损伤分布的重要性需要进一步研究。
