**作者：**李三保**中文摘要：**The mechanical behaviour of interfacial cracks and dislocations in composite materials is investigated. The stress intensity factor at a crack tip along a perfect bonded interface arising from screw dislocation is found to have the same expression as that of single phase media if the shear modulus of the single phase medium is replaced by the harmonic mean of the shear moduli of both media in the composite. The mode I stress intensity factor at a crack tip along the sliding interface arising from edge dislocation is the same as that of a single phase medium if the elastic constant E/(1-n/sup 2/) of the single phase media is replaced by the harmonic mean of E/(1-n/sup 2/) of both media in the composite, where E and n are the Young's modulus and Poisson's ratio, respectively. However, mode II and mode III stress intensity factors at a sliding interfacial crack arising from edge and screw dislocations are zero. The mode III stress intensity factor at a crack tip along a perfect bonded interface and mode I stress intensity factor at a crack tip along a sliding interface arising from an applied load have the same expression as their single phase media counterparts because their expressions do not contain an elastic constant. Under high temperature creep growth, the expression of stress in composite materials has the same form as that in a single phase material if E/(1-n/sup 2/) of the single phase medium is replaced by the harmonic mean of E/(1-n/sup 2/) of both media in the composite. The stress intensity factors at a crack tip along a perfect bonded interface arising from edge dislocation and a mode I applied load are mixed and cannot be obtained from the solution of single phase media with suitable arrangement.**英文摘要：**--**中文關鍵字：**perfect bonded interface, sliding interface, interfacial crack, screw dislocation, edge dislocation, stress intensity factor, image force**英文關鍵字：**--