In this seminar I will give a brief overview on viscoelastic fluids and rheology. Rheology is the science that deals with the way materials deform when forces are applied to them. To learn anything about the rheological properties of a material, we must either measure the deformation resulting from a given force or measure the force required to produce a given deformation. 

So, we study rheological properties through some experiments such ad steady shear, Small amplitude oscillatory shear, stress growth upon inception of steady shear flow and stress relaxation after a sudden shearing displacement. 

Moreover, we present a new model that includes logarithmic strains. 

Finally, comparisons between the new model and a classical one (the upper-convected Maxwell model) will be given to illustrate similarities and differences.