The formulation for thermal stress and electric displacement in an in®nite thermopiezoelectric plate with an interface and multiple cracks is presented. Using Green's function approach and the principle of superposition, a system of singular integral equations for the unknown temperature discontinuity de®ned on each crack face is developed and solved numerically. The formulation can then be use...

The fatigue crack growth behavior of a cracked and patch-repaired AA2024-T3 panel has been monitored by acoustic emission (AE). It was found that the overall crack growth rate was reduced and the crack propagation into the adjacent rivet hole was also retarded by introducing the patch repair. AE signals due to crack growth after the patch repair and those due to disbonding of the aluminum-patch...

We describe the first of two large-scale atomic simulation projects on materials failure performed on the 12-teraflop ASCI (Accelerated Strategic Computing Initiative) White computer at Lawrence Livermore National Laboratory. This is a multimillion-atom simulation study of crack propagation in rapid brittle fracture where the cracks travel faster than the speed of sound. Our finding centers on ...

Crack propagation across interlayers separating adjoining brittle plates in flexure was studied using a model glass/epoxy/glass system. A transverse starter crack in the center glass plate was made to propagate to the nearest epoxy interface, where it arrested. System failure occurred at some higher load by crack reinitiation from pre-existing flaws in the adjoining glass surface, not by contin...

Frictional sliding along an interface between two identical isotropic elastic plates under impact shear loading is investigated experimentally and numerically. The plates are held together by a compressive stress and one plate is subject to edge impact near the interface. The experiments exhibit both a crack-like and a pulse-like mode of sliding. Plane stress finite element calculations modelin...

DC electric potential technique has been used to monitor crack growth in conductive materials. A constant DC current is passed through these materials and the crack length is measured through the changes in the electrical voltage at the crack mouth. However, this method is not applicable in crack growth measurement in nonconductive materials or adhesively bonded joints. For these materials, a n...

A FGM layer sandwiched between two isotropic layers weakened by several interface cracks under antiplane loading is studied. This paper examines the modelling of cracks by distribution of strain nuclei along crack lines. In this investigation, the Volterra-type screw dislocation employed between FGM and an elastic layer. To solve the dislocation problem, the complex Fourier transform is applied...

A FGM layer sandwiched between two isotropic layers weakened by several interface cracks under antiplane loading is studied. This paper examines the modelling of cracks by distribution of strain nuclei along crack lines. In this investigation, the Volterra-type screw dislocation employed between FGM and an elastic layer. To solve the dislocation problem, the complex Fourier transform is applied...

Crack propagation along one of the interfaces between a thin ductile adhesive layer and the elastic substrates it joins is considered. The layer is taken as being elastic-plastic, and the fracture process of the interface is modeled by a traction-separation law, characterized by the peak separation stress 6 and the work of separation per unit area To. Crack growth resistance curves for mode I l...

Ab~act-The ductile vs brittle behaviour of metal-ceramic interfaces is discussed within an atomistic framework, in which the mechanical response of an interfucial crack is assumed to be ultimately controlled by the competition between atomic decohesion and dislocation nucleation ahead of the crack tip. As in later versions of the Rice-Thomson model, this competition may be evaluated in terms of...