| With the continuous development of science and technology, composite materials for its superior performance,are widely used in production, all areas of life. However, experience from daily life, we know that, the combining materials are always destroyed form union or near the interface first, from daily life. So, to analysis of interface crack as a reliant evaluation to strength of composite materials have important meaning. At present, the study of interfacial crack in isotropic materials was conducted much earlier and more extensively [1-7]. Recently, the research of stress field to the interface crack tip on orthotropic bi-material without oscillatory singular had some results [9-11].But the literature of orthogonality bi-materials anti-plane interface end are seldom been seen.In this paper, using composite complex function method of material fracture, the new specific stress function was constructed in this paper, by solving a class of partial differential equations boundary value problems, the problem of an orthotropic bi-material with antiplane interfacial crack, an orthotropic bi-material with antiplane of flat lap interface end were studied .in the end, special interface end are studied too. The main study process and production are as follows:1. The problem of an orthotropic bi-material with antiplane interfacial crack was studied. The expression of stress field, displacement field and stress intensity factor around the crack tip were derived, and the singularity of stress near the crack tip was fixed. The results show that stress has singularity of without oscillatory.2. The problem of orthotropic bi-materials anti-plane interface end of flat lap was studied. The expression of the stress fields, the displacements fields and the stress intensity factor of flat lap interface end near the crack tip are derived. The result show: the stress fields do not to exist singularity when of two materials constant ratio; the stress field exist power singularity, and singularity exponent trend to increasing when .3. The problem of an orthotropic bi-material anti-plane interface end was studied. The characteristic equation of symmetrical interface end was derived .The result show: (1) whenθ1 =θ2 =π2, the singularity exponent are greater than 1, stress has no singularity; (2) whenθ1 =θ2 =π4, combination of materials for different, the singularity exponent with the combination of material parameters change. The greater difference between the material properties of , the stronger singularity. From the results, we know that the stress of anti-plane isotropic bi-material has no singularity whenθ1 =θ2≤π2,λ≥0; andλ< n the relationship betweenanti-plane stress singularity index and the angle is a linear equation whenθ1 =θ2 >π2.The results are consistent with the literature [15] .The characteristic equation of asymmetric interface end was derived .The result show:(1) whenθ1 =π2,θ2 = ?π3,λ(0 < Reλ< 1)is increasing with increases;When the infiniteed ,λis trending to 0.4.With the increases,λis trending to -1. As can be seen,the material 1 is solider far than material 2,the interface end has no singularity . (2)θ1 =π2,θ2 = ? 34πthe stress fields of dissimilar orthotropic composite materials have power singularity, but when the Material Parameters ratio of incresed, characteristic value ofλis trending to -1.These results show that interface stress singularity on orthotropic bimaterials of anti-plane with the power singularity, - 1/2 singularity as with the single plane or has no singularity. The results will be extremely useful to structural design, and engineering application, making due contribution to the theoretical study of interface mechanics and come into being important effects to more development and generalizing application of composite materials.
|
PDF Full Text Request