Debonding of an inclusion from the surrounding matrix in the presence of a nearby crack tip is studied numerically. Finite element models of symmetric three-point bend configurations are implemented in conjunction with a stiffness degradation method and the maximum tensile stress criteria to investigate the influence of debonding on crack tip parameters. The geometry considered is a single edge...

As observed by Needleman and co-workers [1], it is still not clear to what extent the initially elastic cohesive surfaces are more appropriate than the initially rigid cohesive surfaces for a given application. In this work, an analysis where the initially elastic model is approached asymptotically to the initially rigid is proposed. The purpose of this analysis is to gain more insight into the...

 In this research, a numerical modeling was utilized to calculate the stresses caused during thermal cycling in a functionally graded thermal barrier coating (FG - TBC). The temperature – dependent material response of this protective material was taken into account and the effects of thermal cycle and interface morphology of the ceramic / metallic layer in functionally graded coating system wa...

Existing adhesion theories and associated mechanisms are reviewed and applied to bituminous crack sealants and to the crack sealing of asphalt concrete (AC) roadways. As such, the possible contribution of each mechanism to the sealant-interface-AC system is critically assessed. Of six possible adhesion mechanisms, only sealant adsorption and interlock can explain adhesion between sealant and AC...

This paper discusses the use of fracture mechanics for the microstructure tailoring of a fiber reinforced Engineered Cementitious Composite (ECC) to achieve extreme tensile ductility at the composite scale. It demonstrates that fracture mechanics applied to control fracture phenomena at the micro and meso material scales can lead to suppression of fracture failure at the macro structural scale....

Ceramic coatings deposited on metal substrates generally develop significant compressive stresses when cooled from the temperature at which they are processed as a result of thermal expansion mismatch. One of the main failure modes for these coatings is edge delamination. For an ideally brittle interface, the edge delamination of a compressed thin film involves mode II interface cracking. The c...

Three-dimensional enriched finite elements are used to compute mixed-mode stress intensity factors (SIFs) for three-dimensional cracks in elastic functionally graded materials (FGMs) that are subject to general mixed-mode loading. The method, which advantageously does not require special mesh configuration/modifications and post-processing of finite element results, is an enhancement of previou...