1 / 8

Rheology

Rheology. Goal : To understand some simple stress-strain relationships. Relationship between stress and strain. Why did various types of putty deform differently? Was stress constant in these experiments? Was temperature constant? What other variables exist?.

ayasha
Télécharger la présentation

Rheology

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Rheology Goal: To understand some simple stress-strain relationships

  2. Relationship between stress and strain Why did various types of putty deform differently? • Was stress constant in these experiments? • Was temperature constant? • What other variables exist?

  3. Rheology: The study of relationship between stress and strain in deforming materials • The term rheology is also used as a noun for a material property. For instance: The rheology of glacial ice. • If two materials have different rheologies, we say they are rheologically (adverb) different

  4. Elastic rheologies • Example — rubber band • Exhibit recoverable strain • Elastic deformation is strain-rate independent

  5. Elastic behavior described by Hook’s Law σd = E x e E = Young’s modulus e = elongation Can draw strain/time and stress/strain curves for this

  6. Viscous rheologies • Viscous materials deform by flowing • Examples: Honey, motor oil, water, and Lava. Silly Putty is an approximately viscous material. • Exhibit permanent, nonrecoverable strain. • Strain-rate dependent: Deform Silly Putty as an example

  7. Viscous flow is described by ė = σd/η η = material’s viscosity Can draw strain/time and stress/strain-rate curves for this

  8. Real rocks.... Combination of elastic/frictional-brittle and nonlinear-viscous behavior • The transition is dependent on both temperature (T) and strain rate (ė) • Can use silly putty as an example the effects of both T and ė

More Related