Subproject C4: Theoretical and experimental investigations on the structural-mechanical behaviour of textile-reinforced thermoplastic composite components under crash and impact loads

Supervision
Prof. Dr.-Ing. habil. Maik Gude
TU Dresden
Institute of Lightweight Engineering and Polymer Technology 
01062 Dresden
Germany
Phone: +49 351 463-38153
Fax: +49 351 463-38143

 
Prof. Dr. rer. nat. habil. Dr. h. c. Karl-Heinz Modler
TU Dresden
Institute of Solid Mechanics 
01062 Dresden
Germany
Phone: +49 351 463-32989
Fax: +49 351 463-33361


Dr.-Ing. Albert Langkamp
TU Dresden
Institute of Lightweight Engineering and Polymer Technology
01062 Dresden
Germany
Phone: +49 351 463-38151
Fax: +49 351 463-38143


 
Abstract
The goal of subproject C4 is the experimental and theoretical analysis of the mechanical behaviour of textile-reinforced composites with thermoplastic matrix under highly dynamic loading. These investigations are used for the development of novel adapted material models. On the basis of the material characterisation in the first phase, further investigations on the strain-rate-dependent material behaviour under out-of-plane loads as well as on the structural behaviour of curved composite components and on textile-adapted joining elements are planned.

In the first phase, highly dynamic in-plane tensile and compression tests on textile-reinforced composites with thermoplastic matrix and woven or knitted fabric reinforcement were performed for the determination of strain-rate- and orientation-dependent stiffness and strength characteristics and for the identification of the material-specific failure and damage behaviour. Therefor, novel testing methods and devices were developed, which enable a defined loading and accurate strain and damage analysis. Based on the experimental results, approaches for extended material models were developed, which include the strain-rate-dependent deformation behaviour on the one hand and the fracture-mode-specific failure behaviour on the other hand. The models were used for first numerical crash and impact simulations on plane thermoplastic composite components.

In the second research phase, investigations on the behaviour of novel textile-reinforced thermoplastic composites in through-thickness direction under highly dynamic loads are focused for the enhancement of the developed material models in terms of 3D stress, deformation, failure and damage analysis. These models will subsequently be used for the numerical simulation of geometrically complex structures under crash and impact loads. The validation of the numerical models is performed by experiments in adapted crash and impact rigs and a novel drop tower.

Further experimental investigations on highly dynamically loaded textile-thermoplastic structures with cut outs and joining elements will be performed together with subproject B2 for the enhancement of models for notched stress and notched strength analyses with regard to the strain-rate dependence. With the models developed in subprojects C4 and B2, first crash relevant demonstrator components will be designed and afterwards tested in the drop tower regarding their deformation and failure behaviour. The investigations built a main basis for the development and design of a generic technology demonstrator in function-integrating multi-material design in the third research phase.