Wei Hong's blog

The Society of the Engineering Science is sponsoring the 47th Annual Technical Meeting (SES2010) on October 4-6, 2010 at Iowa State University in Ames, IA. The meeting is held on biannual basis as a standalone meeting to foster and promote the exchange of ideas and information among the various disciplines of engineering and the fields of physics, chemistry, mathematics, bioengineering and related scientific and engineering fields.

Dear Colleague:

The Society of the Engineering Science is sponsoring the 47th Annual Technical Meeting (SES2010) on October 4-6, 2010 at Iowa State University in Ames, IA. The meeting is held on biannual basis as a standalone meeting to foster and promote the exchange of ideas and information among the various disciplines of engineering and the fields of physics, chemistry, mathematics, bioengineering and related scientific and engineering fields.

Due to the migration of mobile molecules and ions, a thin diffusive layer of distributed charge - the electric double layer - forms at the interface between a polyelectrolyte gel and a liquid ionic solution.  When two polyelectrolyte gels are brought closely together, the electric double layers overlap and interact with each other, resulting in an effective repulsion.  The multiphysics coupling nature of soft gels makes their surface interactions significantly different from the interactions between rigid solids.

The electric-field-induced phase transition was investigated under mechanical confinements in bulk samples of an antiferroelectric perovskite oxide at room temperature. Profound impacts of mechanical confinements on the phase transition are observed due to the interplay of ferroelasticity and the volume expansion at the transition. The uniaxial compressive prestress delays while the radial compressive prestress suppresses it. The difference is rationalized with a phenomenological model of the phase transition accounting for the mechanical confinement.

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.

Immersed in an ionic solution, a network of polyelectrolyte polymers imbibes the solution and swells, resulting in a polyelectrolyte gel. The swelling is reversible, and is regulated by ionic concentrations, mechanical forces, and electric potentials. This paper develops a field theory to couple large deformation and electrochemistry. A specific material model is described, including the effects of stretching the network, mixing the polymers with the solvent and ions, and polarizing the gel.

The Department of Aerospace Engineering at Iowa State University invites applications for multiple tenure-track faculty positions at the assistant, associate, or full professor ranks to begin August 2009. Applicants are sought in all areas of aerospace engineering and engineering mechanics but preference will be given to those with interest and expertise in aerospace structures/mechanics of materials, multidisciplinary design and analysis, experimental thermal-fluids, propulsion, wind energy, and wind engineering.