Chapter 8.3

Chapter 8.3 - Crack propagation Cracks with sharp tips...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
11 MSE 2090: Introduction to Materials Science Chapter 8, Failure Crack propagation Energy balance on the crack Elastic strain energy: ¾ energy stored in material as it is elastically deformed ¾ this energy is released when the crack propagates ¾ creation of new surfaces requires energy ductile Cracks with sharp tips propagate easier than cracks having blunt tips 2 / 1 t 0 m a 2 ρ σ σ In ductile materials, plastic deformation at a crack tip “blunts” the crack. brittle deformed region 2 1 2 / s c π a E γ σ = Critical stress for crack propagation: γ s = specific surface energy for ductile materials γ s should be replaced with γ s + γ p where γ p is plastic deformation energy Griffith's criterion
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
MSE 2090: Introduction to Materials Science Chapter 8, Failure Two standard tests, the Charpy and Izod, measure the impact energy (the energy required to fracture a test piece under an impact load), also called the notch toughness
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page1 / 5

Chapter 8.3 - Crack propagation Cracks with sharp tips...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online