Optimization of composites based on micro-macro transition in the nonlinear regime

该项目解决了复合材料的局部布局的优化，如纤维增强聚合物（FRP）和混凝土（RC），相对于整体结构响应。这些全局目标，例如极限荷载和延性，基本上由非线性材料演化（开裂、脱粘、分层等）控制。在小尺度上，在局部水平上应用本构律，如损伤公式或光滑/强不连续性。与宏观的大尺度解相反，小尺度表示需要精细的分辨率。利用Hughes 1998年提出的变分多尺度方法（VMM），将小尺度解投影到大尺度上。一旦项目的主要组成部分得到验证，该方法被应用到优化选定的例子，例如纺织钢筋混凝土的调整或后加强钢筋混凝土板的FRP层。总之，可以说，这个项目涉及多尺度框架中的结构的多尺度优化。

The project addresses the optimization of the local layout of composite materials, like Fiber Reinforced Polymers (FRP) and Concrete (RC), with respect to the overall structural response. These global objectives, for example ultimate load and ductility, are essentially controlled by the nonlinear material evolution (cracking, debonding, delamination etc.) on a small scale applying constitutive laws, like a damage formulation or smooth/strong discontinuities, on a local level. Opposite to the macroscopic large scale solution the small scale representation needs a fine resolution. Utilizing the Variational Multiscale Method (VMM) introduced by Hughes 1998 the small scale solution is projected onto the large scale formulation. Once the major component of the project is verified the method is applied to the optimization of selected examples, for instance the tuning of textile reinforced concrete or the post-strengthening of a RC slab by a FRP layer. In conclusion it can be said that this project deals with multiscale optimization of structures posed in a multiscale framework.