research

The Idaho National Laboratory (INL) Energy Resources Recovery & Management Department invites applications for one, or possibly two, post-doctoral research positions in the area of numerical simulations of coupled thermal-hydro-geomechanical processes in geothermal reservoirs. The position(s) will be available in October 2009 and will be renewable for up to 3 years. An earlier start is possible, depending on project development.

Through this post I wish to share some recent results that provide new insights into the role of a defect-core in mechanics. Below is the abstract of the work, and the references and links to the preprints of articles. I look forward to your comments and suggestions.



Abstract:

When a block of an elastomer is bent, the compressed surface may form a crease. This paper analyzes the critical condition for creasing by comparing the elastic energy in a creased body and that in a smooth body. This difference in energy is expressed by a scaling relation. Critical conditions for creasing are determined for elastomers subject to general loads and gels swelling under constraint. The theoretical results are compared with existing experimental observations.

Dear all,

     Many numerical implementation of plasticity model uses spectral decomposition to represent the Cauchy stress, elastic strain,  such that stress update algorithm is written in the principal directions. As a result, I wonder what makes it benefical to write the stress update algorithm in spectral form? 

 Thanks,

WaiChing Sun

  The difference to the common model used is the f,g terms. The 3D FEM formulation has been derived and a new fortran program is written. The derivative matrix is symmetric. But the calculation result does not converge. I have tried every means to get a converging result. But it doesn't work, the residual norm always increases.