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

• Applicant: Professor Dr.-Ing. Ekkehard Ramm
• Subject Area: Mechanics
• Term: from 2003 to 2010
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5470270

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.

• DFG Programme: Research Units
• Subproject of: FOR 509: Multiscale Methods in Computational Mechanics