This work approaches the fields of homogenization and of materials design for the linear and nonlinear mechanical properties with prescribed properties-profile. The set of achievable properties is bounded by the zeroth-order bounds (which are material specific), the first-order bounds (containing volume fractions of the phases) and the second-order Hashin-Shtrikman bounds with eigenfields in terms of tensorial texture coefficients for arbitrarily anisotropic textured materials.

Hot stamping is a hot drawing process which takes advantage of the polymorphic steel behavior to produce parts with a good strength-to-weight ratio. For the simulation of the hot stamping process, a nonlinear two-scale thermomechanical model is suggested and implemented into the FE tool ABAQUS. Phase transformation and transformation induced plasticity effects are taken into account. The simulation results regarding the final shape and residual stresses are compared to experimental findings.

Dynamisch-mechanische Analyse wird verwendet um die temperaturabhängige, anisotrope viskoelastische Steifigkeit, Schädigungsinduzierte Steifigkeitsdegradation sowie physikalische Alterung von Polypropylen und dem im Fließpressverfahren hergestellten langfaserverstärkten Polypropylen zu untersuchen. Basierend auf Mikro-Computertomographiedaten wird die Approximation linear elastischer Eigenschaften unter Verwendung der Mori-Tanaka-Methode dargestellt. Dynamical mechanical analysis is used to investigate the temperature dependent, anisotropic visco-elastic stiffness, damage induced stiffness degradation as well as physical aging of polypropylene and the anisotropic compression molded long fiber reinforced polypropylene. Based on micro-computer tomography data, the approximations of the linear elastic properties using the Mori-Tanaka method are presented.

An overview of different methods for the derivation of extended continuum models is given. A gradient plasticity theory is established in the context of small deformations and single slip by considering the invariance of an extended energy balance with respect to Euclidean transformations, where the plastic slip is considered as an additional degree of freedom. Thermodynamically consistent flow rules at the grain boundary are derived. The theory is applied to a two- and a three-phase laminate.

In this work, the dynamic behavior of a lean combustion race engine is investigated with regard to cycle-averaged component temperatures, heat fluxes and piston failure under high cycle fatigue loading. A special focus lies on the influence of various engine settings, like ignition time and the airfuel ratio. For the introduced stationary, as well as transient, temperature calculation method, in cylinder pressure curves are measured and processed statistically by probability density functions.

The focus of this work lies on the microstructure-based modeling and characterization of a discontinuous fiber-reinforced thermoset in the form of sheet molding compound (SMC). A microstructure-based parameter identification scheme for SMC with an inhomogeneous fiber orientation distribution is introduced. Different cruciform specimen designs, including two concepts to reinforce the specimens' arms are evaluated. Additionally, a micromechanical mean-field damage model for the SMC is introduced.

A single-crystal plasticity model as well as a gradient crystal plasticity model are used to describe the creep behavior of directionally solidified NiAl based eutectic alloys. To consider the transition from theoretical to bulk strength, a hardening model was introduced to describe the strength of the reinforcing phases. Moreover, to account for microstructural changes due to material flux, a coupled diffusional-mechanical simulation model was introduced.

A discontinuous fiber-reinforced thermoset material produced by the Sheet Molding Compound process is investigated. Due to the process-related fiber orientation distribution, a composite with an anisotropic microstructure is created which crucially affects the mechanical properties. The central objectives are the modeling of the thermoelastic behavior of the composite accounting for the underlying microstructure, and the experimental characterization of the pure resin and the composite material.