Nano-scale observation of frictional deformation at Ag single point contact with MEMS-in-TEM setup

System identification of a beam with frictional contact

The nonlinear system becomes an area with numerous investigations over the past decades. The conventional modal analysis could not be  applied on nonlinear continuous system which makes it impossible to construct the reduced order models and obtain system response based on limited number of measurement points. Nonlinear normal modes provide a useful tool for extending modal analysis to nonlinea...

Mixed finite element formulation in large deformation frictional contact problem

This paper presents a mixed variational framework and numerical examples to treat a bidimensional friction contact problem in large deformation. Two different contact algorithms with friction are developed using the 2D finite element code PLAST2. The first contact algorithm is the classical node-on-segment, and the second one corresponds to an extension of the mortar element method to a unilate...

Direct in situ observation of metallic glass deformation by real-time nano-scale indentation

A common understanding of plastic deformation of metallic glasses (MGs) at room temperature is that such deformation occurs via the formation of runaway shear bands that usually lead to catastrophic failure of MGs. Here we demonstrate that inhomogeneous plastic flow at nanoscale can evolve in a well-controlled manner without further developing of shear bands. It is suggested that the sample und...

Plasticity aspects of nano scale contact

Fixed point strategies for elastostatic frictional contact problems

Analysis and theoretical comparison between several fixed point strategies and Uzawa algorithms (for classical and augmented Lagrangian) are performed to solve the so called Signorini problem with Coulomb friction without any regularization. Thanks to a formalism coming from convex analysis, some new fixed point strategies are presented and compared to already known methods. The analysis is fir...