Nonlinear response to probe vitrification


Project Voigtmann/Fuchs (Konstanz)

Nonlinear mechanical response of supercooled melts under applied stress


We study the nonlinear response of supercooled melts and glass formers to time-dependent, strong applied stresses. To discover whether and when metallic and colloidal glasses yield homogeneously or locally under applied stress, a microscopic theory is developed, based on the integration through transients (ITT) approach in combination with a generalization of inhomogeneous mode-coupling theory (i-MCT). Spatially dependent elastic and plastic deformations, yielding and flow are studied, and microscopic mechanisms leading to strain localization are investigated, to provide insights into the transport mechanisms in melts and amorphous solids far from equilibrium.

P3 Voigtmann/Fuchs, DLR Köln und Universität Konstanz

Nonlinear mechanical response of supercooled melts under applied forces

The nonlinear response of supercooled, glass-forming melts under force-driven inhomogeneous
flow is studied using an integration-through-transients approach combined with modecoupling-
theory approximations and using mesoscopic lattice-Boltzmann simulations. Pressuredriven
flow through channels will be analyzed with both methods, allowing to investigate far from
equilibrium the importance of visco-elastic, retarded and non-local memory effects in the structural
relaxation, and the nonlinear yielding behavior in glass-forming liquids.