Rheology of Materials

Rheology is the study of the deformation and flow of materials under the influence of an applied mechanical load. In the field of materials science, this discipline is particularly relevant to the following areas:

            - Viscoelasticity

            - Plasticity

            - Viscoelasticity

            - Non-Newtonian fluids

In practice, rheology makes it possible to characterize the macroscopic mechanical properties of materials whose behavior cannot be described by classical theories of elastic solids and Newtonian fluids (with constant viscosity). Such materials can thus be considered to exhibit behavior that lies between that of a solid and a fluid, and between elastic and viscous behavior.

The objective of this Course Unit (UE) is to enable third-year mechanical engineering students to better understand certain other third-year courses (notably, strength of materials, fluid mechanics, mechanics of deformable solids, and structural design) and to prepare them to more effectively tackle future courses at the master’s level (general-purpose standard materials, etc.).

To this end, this course unit will explore the various typical mechanical behaviors of different classes of materials (metals, polymers, granular materials, wood, etc.) by linking them to their specific (micro-)structural organization and composition, which determine their deformation modes. The concepts of isotropy, orthotropy, transverse isotropy, and total anisotropy will be discussed. In addition, an overview of the main types of experimental tests (e.g., uniaxial tensile testing, biaxial tensile testing, work hardening tests, creep tests, relaxation tests, etc.) will be provided.

Rigid Body Mechanics

Recommended prerequisites*:

Knowledge of Materials and Their Classification

Final Exam

1) Different types of materials

2) Different Types of Experimental Tests

3) Different mechanical behaviors (associated with these experimental tests)

4) Rheological models to represent these behaviors

1. a) Rheological models: The course begins with a general overview of the distinctions between solid and fluid behavior, as well as elastic and viscous behavior, taking into account the corresponding time-dependent aspects. An introduction to plasticity (a “fluid-like” deformation of a solid beyond a certain mechanical stress threshold) is also presented

Next, the main rheological models (along with their associated analog models) are presented, along with their use in determining the corresponding mechanical properties. Finally, methods for combining these models in series and/or in parallel to develop more complex models are discussed.