Rheology, the study of the flow and deformation of matter, is an old discipline undergoing a renaissance. In its widest sense, it includes classical fluid mechanics and elasticity which treat the flow of Newtonian liquids, such as water, and small deformations of hard solids, such as wood and steel. Using the special term "rheology" for these subjects alone would not be justified, since they have been extensively studied for more than 170 years, and are an accepted part of most university curriculums.

In the Rheology Research Center, students have numerous opportunities to investigate subjects such as nonlinear viscoelasticity in the extrusion blow molding of plastic bottles. (40K JPG)

In practice, the word "rheology" normally refers to the flow and deformation of "non-classical" materials such as rubber, molten plastics, polymer solutions, slurries and pastes, electrorheological fluids, blood, muscle, composites, soils and paints. These materials can exhibit varied and striking rheological properties that classical fluid mechanics and elasticity cannot describe. Though the word "rheology" was coined in 1929, the rapid development of the subject began 20 years later.

Research in rheology is conducted through the Rheology Research Center, and involves twelve faculty members from chemical engineering, chemistry, mechanical engineering, and nuclear engineering and engineering physics (Prof. Malkus).

rrc.engr.wisc.edu