Abstract: In this paper, double dissimilar orthotropic composite materials interfacial crack is studied by constructing new stress functions and employing the method of composite material complex. When the characteristic equations' discriminates Δ1>0 and Δ2>0, the theoretical formula of the stress field and the displacement field near the mode I interface crack tip are derived, indicating that there is no oscillation and inter-embedding between the interfaces of the crack.

Key words: orthotropic, interface crack, crack tip, stress field