The crack theory in conventional linear elasticity fracture mechanics is ex
tended to quasicrystal linear elasticity fracture mechanics. A decagonal qu
asicrystal containing a Griffith crack penetrating through the solid along
the period direction is considered. By means of a general solution, the ana
lytical expressions for the entire stress field are obtained. The asymptoti
c behaviour of the stress around the crack tip indicates that the stress ne
ar the crack tip exhibits the square root singularity. The singularity in t
he phason stress field arises from that the phonon and phason fields couple
with each other. The crack strain energy and energy release rate are also
given.