Abstract:The T-stress near the tips of a cruciform crack with unequal arms in the cubic quasicrystals is analyzed. The associated boundary value problems can transform to a system of singular integral equations by using the integral transformation technique. According to the stress difference method, T-stresses of phonon field and phason field can be expressed as the sum of an integral involving crack opening displacements and applied loading at infinity. Crack opening displacements play a leading role in determining T-stresses of phonon field and phason field. The role of the T-stresses in brittle fracture for cubic quasicrystals is emphasized. Moreover, the influence of the ratio of two crack-arm lengths b/a and the crack opening displacements on the T-stresses of a cruciform crack is examined.