Patran Nastran - Crack

: Creating the "flaw" or crack tip within the mesh.

: Using singular elements (quarter-point nodes) at the crack tip to capture the high stress gradients accurately. Material Properties : Defining fracture toughness ( KICcap K sub cap I cap C end-sub Crack Patran Nastran

Nastran performs the heavy lifting by calculating the — KIcap K sub cap I KIIcap K sub cap I cap I end-sub KIIIcap K sub cap I cap I cap I end-sub : Creating the "flaw" or crack tip within the mesh

: Nastran can use the results of a static or dynamic load to predict the number of cycles ( ) until failure based on S-N or E-N curves. 3. Post-Processing and Visualization Crack Patran Nastran

: Visualizing "Damage" or "Log of Life" to see which parts of the structure will fail first.