In dieser Arbeit wird crazing bei amorphen thermoplastischen Kunststoffen untersucht. Experimente an einem ABS- Kunststoff werden genutzt, um das Deformations- und Schädigungsverhalten zu charakterisieren. Ein homogenisiertes Materialmodel für verteiltes Crazing wurde entwickelt. Simulationen von mikroskopischen Risswachstum und der Vergleich mit Experimenten werden verwendet, um die plastische Zone an einer Rissspitze und das Risswachstum zu untersuchen. In this work crazing in amorphous thermoplastics is investigated. Experiments on an ABS-material are used to characterize the deformation and fracture behavior. A homogenized material model for distributed crazing is developed. Simulation of macroscopic crack growth and the comparison with experiments are used to investigate the plastic zone at the crack tip and the fracture behavior.

The present work deals with the design of structure-preserving numerical methods in the field of nonlinear elastodynamics with an extension to multi-field problems. A new approach to the design of energy-momentum (EM) consistent time-stepping schemes for nonlinear elastodynamics is proposed. Moreover, we extend the formalism to multi-field problems.

The present work deals with multi-field contact problems in the context of IGA. In particular, a thermomechanical as well as a fracture mechanical system is considered, where novel formulations are introduced for both. The corresponding discrete contact formulations are based on a variationally consistent mortar approach adapted for NURBS discretized and hierarchical refined surfaces. Finally, the capabilities of the proposed framework are demonstrated within numerous numerical examples.

The present work deals with the inverse dynamics simulation of underactuated multibody systems. In particular, the study focuses on solving trajectory tracking control problems of differentially flat underactuated systems. The use of servo constraints provides an approach to formulate trajectory tracking control problems of underacutated systems, which are also called underactuated servo constraint problems.

This book deals with the development of constitutive models for the mechanical behavior of amorphous thermoplastic polymers at large strains. A special emphasis lies on the temperature dependency so that the altered material behavior at high temperatures can be considered. To implement the developed constitutive models the software tool AceGen is used by which program code is generated and optimized as well as derivatives are calculated automatically.

The present thesis deals with large deformation contact problems of flexible bodies in the field of nonlinear elastodynamics. Special emphasis will be placed on a consistent spatial and temporal discretization. For the spatial discretization of the underlying bodies, the finite element method will be used. For the contact boundaries the collocation type node-to-surface method as well as the variationally consistent Mortar method will be applied.