opinion

From PhDcomics

Micromechanics---loosely speaking, is the study of heterogeneities in materials and its consequences for material or continuum behavior. This encompasses studies of inclusions, dislocations, cracks or more generally defects. A related problem is that of "coarse-graining" or in other words the effective homogenized properties of a heterogeneous material. The latter is a recurring theme in all of physical sciences not just solid mechanics. Micromechanics, a formidable subject by all means, dominated a substantial part of the history of solid mechanics. Several of our Timoshenko awardees have been associated with this subject, e.g. Eshelby, Hill, Keller, Irwin, Rice among others.

Hello all,

I am studying some simple finite elements for 2d near-incompressible analysis. Particularly, I am interested in the MINI element. It is basically a 3-node triangle element with nodal pressure and displacement degree of freedoms enriched by a bubble function. Could someone that has some experience with these elements point me out about advantages and drawbacks of using these type of elements?

Thanks,

Alejandro.

In the attachment, we show that Truesdell rate can by simplified to Green-Naghdi rate by assuming F .=. R and can be further simplified to Jaumann rate by assuming W .=. R(.)R(T), where .=. means approximately equal

In a stretch dominant deformation, the three rates give different stress rate. This is usually explained by that we need a different tangential modulus for different objective rate. However, it is hard to understand why we need to change "material" modulus when we use a different "mathematical" form of objective rate as they are all supposed to be equivalent.