research

Topology optimization is used to obtain a magnetic source distribution providing levitation of a diamagnetic body or type I superconductor with maximized thrust force. We show that this technique identifies non-trivial source distributions and may be useful to design devices based on non-contact magnetic suspension and other magnetic devices, such as micro-magneto-mechanical devices, high field magnets etc.

If you have seen the very nice PNAS paper which just appeared

Sahli, R., Pallares, G., Ducottet, C., Ben Ali, I.E., Al Akhrass, S., Guibert, M., Scheibert, J., 2018, Evolution of real contact area under shear, Proceedings of the National Academy of Sciences, 115(3), pp. 471-476.

Here we provide a simple explanation.

FACTA UNIVERSITATIS

Series: Mechanical Engineering

DOI: 10.22190/FUME180108007C

Short Communication

FRACTURE MECHANICS SIMPLE CALCULATIONS TO EXPLAIN SMALL REDUCTION OF THE REAL CONTACT AREA UNDER SHEAR

UDC 539.6

I hope some of you find this work interesting, the code with the control algorithm (Segurado and Llorca, 2004) to avoid convergence problems in cohesive zone model analyses of crack propagation can be downloaded from empaneda.com/codes (documentation and Abaqus input files are provided).

Non-local plasticity effects on notch fracture mechanics

Emilio Martínez-Pañeda, Susana del Busto, Covadonga Betegón 

Theoretical and Applied Fracture Mechanics (2017)

Auxetic materials with negative Poisson's ratios have important applications across a broad range of engineering areas, such as biomedical devices, aerospace engineering and automotive engineering. A variety of design strategies have been developed to achieve artificial auxetic materials with controllable responses in the Poisson's ratio. The development of designs that can offer isotropic negative Poisson's ratios over large strains can open up new opportunities in emerging biomedical applications, which, however, remains a challenge.

A continuum-based model is presented for the mechanics of bidirectional composites subjected to finite plane deformations. This is framed in the development of a constitutive relation within which the constraint of material incompressibility is augmented. The elastic resistance of the fibers is accounted for directly via the computation of variational derivatives along the lengths of bidirectional fibers. The equilibrium equation and necessary boundary conditions are derived by virtue of the principles of virtual work statement.

Eric Acome, Nicholas Kellaris, Timothy Morrissey, Shane K. Mitchell, Christoph Keplinger

University of Colorado Boulder

Introduction

We introduce a new family of mixed finite elements for incompressible nonlinear elasticity — compatible-strain mixed finite element methods (CSFEMs). Based on a Hu-Washizu-type functional, we write a four-field mixed formulation with the displacement, the displacement gradient, the first Piola-Kirchhoff stress, and a pressure-like field as the four independent unknowns. Using the Hilbert complexes of nonlinear elasticity, which describe the kinematics and the kinetics of motion, we identify the solution spaces of the independent unknown fields.

Inspired by the discussion with Mike Ciavarella on http://imechanica.org/node/22012, I am thinking about a journal with the following attributes:

We present an efficient numerical scheme based on asymptotic numerical method for continuation of spatial equilibria of special Cosserat rods. Using quaternions to represent rotation, the equations of static equilibria of special Cosserat rods are posed as a system of thirteen first order ordinary differential equations having cubic nonlinearity. The derivatives in these equations are further discretized to yield a system of cubic polynomial equations.