Computational technology for analysis of 3D meso-structure effects on damage and failure of concrete

摘要

Methodology for analysis of meso-structure effects on longer-scale mechanical response of concrete is developed. Efficient algorithms for particle generation and packing are proposed to represent 3D meso-structures as collections of discrete features distributed randomly in a continuous phase. Specialised to concrete, the continuous phase represents mortar, while the features are aggregates and voids. Intra- and inter-phase cohesive zones are used for failure initiation and crack propagation. A Monte Carlo approach is proposed to analyse the effects of meso-structure geometrical (volume density, size distribution and shape of features) and physical (strength and energy of cohesive zones) properties, whereas a number of model realisations with identical properties are used for statistical analysis. The results present the relative significance of each meso-structure parameter for the emergent load capacity (tensile strength), damage evolution via micro-crack coalescence and macro-crack patterns, and failure energy density (toughness) of concrete. The proposed methodology is an effective tool for meso-structure optimisation in the design of concrete structures with prescribed requirements for strength and toughness.