bollarding

From bollard +‎ -ing.

bollarding (uncountable)

1. (mechanical engineering) A defect in which a testpiece is deformed into a bollard-like shape.
   • 2006, Jagabanduhu Chakrabarty, Theory of Plasticity:

     An excessive film thickness, on the other hand, produces bollarding in which the diameter of the specimen becomes bigger at the ends than at the middle.

• barreling