%0 doctoral thesis
%@ 
%A Heitbreder, T.

%D 2019
%J 
%N 
%P  
%R doi:10.17877/DE290R-20372
%T Modelling of material interfaces at different length scales
%U https://doi.org/10.17877/DE290R-20372
 
%X This thesis deals with the derivation and implementation of novel material models suitable for material interfaces undergoing large deformations in a geometrically exact setting. The classic cohesive zone framework is a widespread tool to describe and simulate the behaviour of material interfaces. However, the constraints imposed by fundamental physical principles such as thermodynamical consistency, balance equations and material frame indifference are often ignored in classic formulations. By way of contrast, a consistent cohesive zone framework suitable for the analysis of localised elastic and inelastic deformations which only depends on the displacement jump is elaborated in this thesis. Furthermore, a general interface framework is presented that, in contrast to previous works, permits the description of arbitrary material anisotropies by fulfilling all fundamental balance laws in physics as well as the principle of material objectivity. Interfaces highly influence the material behaviour at the technologically relevant macroscale as well as at the microscale which is important, e.g. in materials science. Independent of the considered scale, it is shown by numerical examples that the interaction of bulk energies and interface energies leads, in a very natural manner, to a complex size effect. Depending on the chosen interface framework different effects are presented and discussed. The incorporation of higher gradients into the constitutive interface framework is also investigated.