  We study the effect of heterogeneous load sharing in the fiber bundle models
of fracture. The system is divided into two groups of fibers (fraction $p$ and
$1-p$) in which one group follow the completely local load sharing mechanism
and the other group follow global load sharing mechanism. Patches of local
disorders (weakness) in the loading plate can cause such a situation in the
system. We find that in 2d a finite crossover (between global and local load
sharing behaviours) point comes up at a finite value of the disorder
concentration (near $p_c\sim 0.53$), which is slightly below the site
percolation threshold. We numerically determine the phase diagrams (in 1d and
2d) and identify the critical behavior below $p_c$ with the mean field behavior
(completely global load sharing) for both dimensions. This crossover can occur
due to geometrical percolation of disorders in the loading plate. We also show
how the critical point depends on the loading history, which is identified as a
special property of local load sharing.
