Glass Fracture Analysis Flashcards
What is CRATERING EFFECT in glass fracturing?
When a window is struck, small particles of glass are blown away on the opposite side from which the force is applied, giving the area a volcano or crater type shape. The diameter of the crater is independent of the diameter of the projectile.
What are RADIAL LINES in glass fracturing?
When glass reaches its peak elasticity and starts to break, fractures emanate from the point of impact, and radiate outwardly. These fractures are initiated on the opposite side of the compressive force.
What are RIB MARKS (Wallner Lines)?
Stress fractures located along the edge of the broken glass segments. These are accidental characteristics.
What are CONCENTRIC LINES in glass fracturing?
Circular fractures going from radial line to radial line. These originate on the same side as the compressive force.
What are HACKLE MARKS in glass fracturing?
Fines ridges on a fracture surface which run parallel to the direction of propagation of the fracture. These are accidental features.
How can you determine shot sequence?
A fracture will not normally cross over a previously formed fracture, which makes the determination of shot sequence possible.
