Subproject C2: Calculations on complex, curved sandwich structures with large structural variations in stiffness
Supervision
Prof. Dr.-Ing. habil. Volker Ulbricht
TU Dresden
Institute of Solid Mechanics
01062 Dresden
Germany
Phone: +49 351 463-34285
Fax: +49 351 463-37061
Dr.-Ing. Markus Kästner
TU Dresden
Institute of Solid Mechanics
01062 Dresden
Germany
Phone: +49 351 463-32656
Fax: +49 351 463-37061
Abstract
During the first period of subproject C2, an efficient method for computing the macroscopic material behaviour of textile-reinforced composites has been developed. Starting from the physical properties of micro- and mesoscale, the effective macroscopic linear elastic stiffness of textile-reinforced materials and spacer-fabric structures has been computed using homogenization techniques based on the analysis of a representative volume element (RVE) entirely typical for the internal material structure.
In addition to the application and enhancement of homogenization methods, the textile reinforcing structures considered in SFB 639 motivated the development of an efficient modelling strategy for geometrically complex RVE. For this purpose, the extended finite element method (X-FEM) has been adapted to modelling of composites. A novel modelling procedure allows for the automatic generation of X-FEM RVE-models for textile-reinforced materials.
In the second project phase the results obtained so far will be enhanced in order to take nonlinearities into account. Attention is drawn to the formulation of constitutive laws for nonlinear material behaviour of matrix and fibre as well as to nonlinear homogenization techniques.
Motivated by the focus of SFB 639 being drawn to structural applications and demonstrators, nonlinear constitutive equations, modelling procedures and homogenization techniques have to be merged in an adaptive multi-scale simulation. Major benefits of this approach are large flexibility and the abdication of a predefined macroscopic material law.
The analysis of the nonlinear behaviour of constituents and components allows for more precise dimensioning and consistent lightweight design.