Interface delamination is the major weakness limiting diamond coating tool performance in machining. Thus, quantitative characterizations of the interface behavior are important to better understand and design diamond coating tools. In this study, we attempt to apply a cohesive zone model to investigate the coating-substrate interface behavior. The cohesive zone model is based on the traction-s...

Films formed through the drying of nanoparticle suspensions release the build-up of strain through a variety of different mechanisms including shear banding, crack formation and delamination. Here we show that important connections exist between these different phenomena: delamination depends on the dynamics of crack hopping, which in turn is influenced by the presence of shear bands. We also s...

A microresonator-based interfacial fatigue testing technique was used to investigate the subcritical delamination of atomic-layer-deposited alumina coatings along the sidewalls of deep-reactive-ion-etched monocrystalline silicon thin films. This technique ensures loading conditions relevant to microelectromechanical system devices, including kHz testing frequency and fully reversed cyclic stres...

The difference in delamination onset predictions based on the type and location of the assumed initial damage are compared in a specimen consisting of a tapered flange laminate bonded to a skin laminate. From previous experimental work, the damage was identified to consist of a matrix crack in the top skin layer followed by a delamination between the top and second skin layer (+45o/-45o interfa...

A numerically efficient approach for the prediction of consecutive growth of delaminations with curved fronts is developed. The approach is based on the assumption that the delamination grows from its current front to a predefined advanced front and that the delamination front remains smooth during the entire growth process. For computation of the load required to propagate the delamination the...

This paper presents an intelligent interpretation of ultrasonic C-scan results for carbon-fiber-reinforced plastic (CFRP) panels by using fuzzy logic approach. Ultrasonic C-scan results have relatively low resolution and poor imaging quality in anisotropic composites due to the speckle noise produced by the interference of backscattered signals. In this study, fuzzy logic was implemented to acc...

Modeling of crashworthy composite structures is limited by the inability of current generations of finite element crash codes to effectively model certain critical failure modes, such as delamination. Previous efforts to model delamination and debonding failure modes using crash codes have typically relied on ad hoc failure criteria and quasistatic fracture data. Improvements to these modeling ...

The edge crack torsion (ECT) test is designed to initiate mode III delamination growth in composite laminates. An ECT specimen is a rectangular laminate, containing an edge delamination at the laminate mid-plane. Torsion load is applied to the specimens, resulting in relative transverse shear sliding of the delaminated faces. The test data reduction schemes are intended to yield initiation valu...