Imperfect bonding between the constitutive components can greatly affect the properties of the composite structures.An asymptotic analysis of different types of imperfect interfaces arising in the problem of 2D fibrer...Imperfect bonding between the constitutive components can greatly affect the properties of the composite structures.An asymptotic analysis of different types of imperfect interfaces arising in the problem of 2D fibrereinforced composite materials are proposed.The performed study is based on the asymptotic reduction of the governing biharmonic problem into two harmonic problems.All solutions are obtained in a closed analytical form.The obtained results can be used for the calculation of pull-out and pushout tests,as well as for the investigation of the fracture of composite materials.展开更多
The Rayleigh waves in a layered solid medium is dispersive. Using the 'spring' model for a weak interface between two solids, the characteristic equation for the quasi-Rayleigh waves in an isotropic layered so...The Rayleigh waves in a layered solid medium is dispersive. Using the 'spring' model for a weak interface between two solids, the characteristic equation for the quasi-Rayleigh waves in an isotropic layered solid medium with a weak interface is presented. The numerical results for the typical coating structure with the rigid, slip and weak interface are shown. The influence of the interface stiffness constants on the velocity of the quasi-Rayleigh waves is considered. The numerical results show that the interface characteristics of the coating structure can be nondestructively evaluated by employing the quasi-Rayleigh waves in the low frequency band.展开更多
Tension-tension fatigue life tests on nano-grained delaminated low-carbon steel sheet under different fatigue loads are carried out to study the fatigue properties of the steel. The three-dimensional microstructures o...Tension-tension fatigue life tests on nano-grained delaminated low-carbon steel sheet under different fatigue loads are carried out to study the fatigue properties of the steel. The three-dimensional microstructures of the steel are observed by TEM. In addition, the morphology of the fatigue fracture of the specimen under different loads is observed by SEM. The results show that micro-cracks form on the weak interface of the nano-grained steel under low-stress conditions, which hinders the propagation of the main cracks and reduces the fatigue crack propagation rate, resulting in the extending fatigue life of the steel.展开更多
基金supported by the German Research Foundation(Deutsche Forschungsgemeinschaft)(WE 736/30-1)
文摘Imperfect bonding between the constitutive components can greatly affect the properties of the composite structures.An asymptotic analysis of different types of imperfect interfaces arising in the problem of 2D fibrereinforced composite materials are proposed.The performed study is based on the asymptotic reduction of the governing biharmonic problem into two harmonic problems.All solutions are obtained in a closed analytical form.The obtained results can be used for the calculation of pull-out and pushout tests,as well as for the investigation of the fracture of composite materials.
基金the National Natural Science Foundation of China.
文摘The Rayleigh waves in a layered solid medium is dispersive. Using the 'spring' model for a weak interface between two solids, the characteristic equation for the quasi-Rayleigh waves in an isotropic layered solid medium with a weak interface is presented. The numerical results for the typical coating structure with the rigid, slip and weak interface are shown. The influence of the interface stiffness constants on the velocity of the quasi-Rayleigh waves is considered. The numerical results show that the interface characteristics of the coating structure can be nondestructively evaluated by employing the quasi-Rayleigh waves in the low frequency band.
基金supported by the National Natural Science Foundation of China under grant No. 50371073
文摘Tension-tension fatigue life tests on nano-grained delaminated low-carbon steel sheet under different fatigue loads are carried out to study the fatigue properties of the steel. The three-dimensional microstructures of the steel are observed by TEM. In addition, the morphology of the fatigue fracture of the specimen under different loads is observed by SEM. The results show that micro-cracks form on the weak interface of the nano-grained steel under low-stress conditions, which hinders the propagation of the main cracks and reduces the fatigue crack propagation rate, resulting in the extending fatigue life of the steel.
