Variational approach to formation of misoriented microstructures in plastic deformation

The formation of misoriented microstructures in plastic deformation is explained within the framework of continuum mechanics as a result of the reduction of the energetically costly hardening in multislip by local lattice rotations. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

On the role of energy in chip formation

The implicit code ABAQUS/Standard is used to simulate the formation of continuous and segmented chips. Using the described model, the idealized process of friction‐less machining of an elastic ideally‐plastic material is studied. It is shown that Merchant's classical shear angle relation does not hold, as chip formation does not minimize the energy as assumed by Merchant. The model is also used to study segmented chip formation using a realistic material law for the Titanium alloy Ti6Al4V at high cutting speeds.     

Motion of magnetic domain walls

We consider the dynamics of one-dimensional micromagnetic domain walls in layers of uniaxial anisotropy. In the regime of bulk materials, i.e. when the thickness is assumed to be infinite, and the magnetostatic interaction terms appear as local quantities, explicit traveling wave solutions for the corresponding Landau-Lifshitz equation, known asWalker exact solutions, can be constructed. A natural question is whether this construction can be perturbed to the non-local regime of layers of finite thickness. Our stability analysis gives an affirmative answer. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

A closed‐form analysis of material and geometry effects on stress singularities at unsymmetric bimaterial notches

An important issue in the mechanics of adhesive bonds is the knowledge of local mechanical fields. In the present study, an asymptotic analysis of the stress fields near an unsymmetric bimaterial notch with arbitrary opening angle is performed. Using the complex potential method, the order of the singularity of the stress fields at a notch tip can be determined in closed‐form analytical manner, so that the dependency of the occurring singularity exponents on geometry and material properties can be studied systematically.