Papers by Author: Jun Lin Li

Abstract: The orthotropic bi-material plane interface end of a flat lap is studied by constructing new stress functions and using the composite complex function method of material fracture. When the characteristic equations’ discriminates and, the theoretical formulas of stress fields, displacement fields and the stress intensity factor around the flat lap interface end are derived, indicating that there is no oscillatory singularity. There are multiple stress singularities of the orthotropic bi-material plane flat lap interface end.

Abstract: The orthotropic bi-material plane interface end of a flat lap is studied by constructing new stress functions and using the composite complex function method of material fracture. When the characteristic equations’ discriminates and , the theoretical formulas of stress fields, displacement fields and the stress intensity factor around the flat lap interface end are derived, indicating that there is no oscillatory singularity. There are multiple stress singularities of the orthotropic bi-material plane flat lap interface end.

Abstract: The problem of orthotropic composite materials semi-infinite interfacial crack was studied, by constructing new stress functions and employing the method of composite material complex. In the case that the secular equations’ discriminates the and theoretical solutions to the stress fields and the displacement fields near semi-infinite interface crack tip without oscillation and inter-embedding between the interfaces of the crack are obtained, a comparison with finite element example was done to verify the correction of theoretical solution.

Abstract: The problem of orthotropic bi-materials semi-infinite interfacial crack was studied, by constructing new stress functions and using composite complex functions methods of material fracture on plane. It overcame oscillation singularity of stress and existing theoretical solution. When secular equations’ discriminations are and , the theoretical solutions to the stress fields and the displacements fields of semi-infinite interface crack between two dissimilar orthotropic composite materials near the crack tip are obtained.

Abstract: Orthotropic bi-materials interfacial crack was studied, by constructing new stress function and using composite complex function method of material fracture. When secular equations’ discriminant 1 0
< and 2 0
< , the theoretical solutions of stress fields without oscillation singularity and displacement fields without embedding of upper and lower sides are derived.

Abstract: Dynamic problems of Yoffe mode crack are studied under antiplane shear impact in infinite orthotropic functionally graded materials. The shear modules in two directions are assumed to vary in terms with power function form of dual parameters of arbitrary time power. By using integral transform-dual integral equations method, the stress field and dynamic stress intensity factor near crack tip are obtained. And the influences of material in homogenous coefficient and graded parameters and crack moving speed to dynamic stress intensity factor are analyzed in virtue of Matlab software. Results show that the dimensionless dynamic stress intensity factor will decrease with the increase of moving speed of crack, which is opposite to the result of the dynamic problem of infinite strip in FGM. And the dimensionless dynamic stress intensity factor will decrease with the increase of graded parameters and rise with the increase of material in homogenous coefficient.