Skip to main content

research

Non-Metricity and the Nonlinear Mechanics of Distributed Point Defects

Submitted by arash_yavari on

We discuss the relevance of non-metricity in a metric-affine manifold (a manifold equipped with a connection and a metric) and the nonlinear mechanics of distributed point defects. We describe a geometric framework in which one can calculate analytically the residual stress field of nonlinear elastic solids with distributed point defects. In particular, we use Cartan's machinery of moving frames and construct the material manifold of a finite ball with a spherically-symmetric distribution of point defects.

Equivalent strain in large torsional deformation

Submitted by AAGP on
Choose a channel featured in the header of iMechanica

Dear All

Looking for a methodology to convert shear stress-shear strain data from a torsion test in large deformations into true strain-true stress curve, I found two schools of thought: 

 

and

 

I found also in recent papers a strong debate on which should be the correct method. For example:

Journal Club Theme of May 2014: in situ Nanomechanics

Submitted by Anonymous (not verified) on

The in situ nanomechanics is an emerging field that investigates the mechanical properties and deformation mechanisms of nanoscale and nanostructured materials, by integrating the real-time mechanical testing inside electron microscope and the mechanics modeling with atomic resolution. It provides a powerful approach to "visualize" the intrinsic nanomechanical behavior of materials - seeing is believing.

Multiscale Material Modelling

Submitted by Mirkhalaf on

Computational modelling of materials behaviour
is becoming a reliable tool to underpin scientific investigations and to
complement traditional theoretical and experimental approaches. In cases where
an understanding of the dual nature of the structure of matter (continuous when
viewed at large length scales and discrete when viewed at smaller length scales) and
its interdependences are crucial, multiscale materials modelling (MMM)

why the mass matrix of my structure is unsymmetric?

Submitted by Yanhai on

I'm doing an research about a cantilever which can undergoes large rotations along two directions. At the head of the cantilever there is a magnetic particle. When I establish the dynamic model for this cantilever, I just consider the mass of the particle(since the mass of the beam is small). However after I obtian the mass matrix (6 by 6, six DOFs), i found it is not symmetric. I don't know the reason. Can anyone help me? By the way, if the beam undergoes large rotation, will the stiffness matrix(tangent matrix) at each state keep symmetric ? Thank you   

Modeling of Particulate Composites

Submitted by Yogesh_Bisht on
Choose a channel featured in the header of iMechanica

Hi

I am trying to model particulate composites and simulate their stress-strain response. The problem that I am facing is that the inclusions (stiffer than the matrix) are only acting as points of stress concentration. Consequently their is no strengthening and hence no apparent increase in load carrying capacity of the composite. Any help/suggestioin in this regard would be higly appreciated.

Regards