Computational Strategies for Multi-Scale Modeling of Masonry Components and Structures

In the current state of structural engineering, physical experimentation still offers the most reliable means for the determination of parameters for accurate modeling of complex systems. However, engineers usually face time and financial constraints that prevent them from performing such experiments. On the other hand, engineers are in increased need of a reliable predicting computational power so that resources are optimized in the design of new structures and the retrofit of existing ones. Moreover, society expects us to be able to guarantee that structures will have adequate performance during their life. In the present work, a computational framework for the analysis of masonry structures is presented. The framework relies on the well-established theory of micromechanical homogenization. The dissertation consists of two distinct parts: I. Constitutive modeling on the component level and II. Applications at the structural level. First, homogenization is conducted for the elastic parameters. Those parameters are used in a linear elastic analysis of masonry at a macro-scale. Then, with proper engineering judgments, a representative state of strain is determined where the unit cell is subjected to a monotonically increasing state of strain. A stress versus strain relationship is obtained accounting for material regularization so that dimensional effects and proper softening behavior are considered. Effective material parameters are tested against experiments as well as against micro-modeling leading to acceptable results at an affordable computational cost. The framework is applied to the modeling of reinforced concrete frames with masonry infills subjected to in-plane and out-of-plane loading. A three-dimensional model is needed for explicitly accounting for the out-of-plane arching action, which makes the homogenization procedure the only feasible approach for such problem