  We use the local load sharing fiber bundle model to demonstrate a shielding
effect where strong fibers protect weaker ones. This effect exists due to the
local stress enhancement around broken fibers in the local load sharing model,
and it is therefore not present in the equal load sharing model. The shielding
effect is prominent only after the initial disorder-driven part of the fracture
process has finished, and if the fiber bundle has not reached catastrophic
failure by this point, then the shielding increases the critical damage of the
system, compared to equal load sharing. In this sense, the local stress
enhancement may make the fracture process more stable, but at the cost of
reduced critical force.
