The effects of temperature and loading rate on delamination growth were studied. The delamination fracture toughness of IM7/K3B was measured at 149°C, 177°C, and 204°C. At each temperature the tests were performed with a variety of loading rates so that the delamination initiated over the range of time from 0.5 sec to 24 hrs. The double cantilever beam (DCB) test was used to measure fracture to...

Delamination of premigratory neural crest cells depends on a balance between BMP/noggin and on successful G1/S transition. Here, we report that BMP regulates G1/S transition and consequent crest delamination through canonical Wnt signaling. Noggin overexpression inhibits G1/S transition and blocking G1/S abrogates BMP-induced delamination; moreover, transcription of Wnt1 is stimulated by BMP an...

Channeling cracks in low-k dielectrics have been observed to be a key reliability issue for advanced interconnects. The constraint effect of surrounding materials including stacked buffer layers has been studied. This paper analyzes the effect of interfacial delamination on the fracture condition of brittle thin films on elastic substrates. It is found that stable delamination along with the gr...

Drilling is the most frequently employed operation of secondary machining for fiber-reinforced materials owing to the need for structure joining. Delamination is one of the serious concerns during drilling. Practical experience shows that an eccentric twist drill or an eccentric candle stick drill can degrade the quality of the fiber reinforced material. Comprehensive delamination models for th...

In order to provide effective solid lubrication Ni3Al coating, 10 wt.% Ag and different amounts of MoO3 lubricant were mechanically mixed with the SHSed powder sprayed HVOF. Microstructure, mechanical properties, tribological behavior from 25 °C 800 coatings studied, basic wear mechanisms explored discussed as well. Results show that hardness adhesive bonding strength are slightly decreased, wh...

Finite element analysis of the delamination crack propagation in laminated composites is presented. Fracture mechanics based Virtual Crack Closure Technique (VCCT), and the cohesive element technique, have been used to simulate the delamination initiation and propagation under Mode-I type loading. Detailed description of the parameter selection process for these two techniques with ABAQUS®/Stan...

The inconsistencies accompanied with material properties tipically cause the rise of delamination risk in composites made of different types of glass and crabon fibers. In this study, the delamination of a composite beam reinforced with a carbon layer under bending load is investigated. To this end, a small piece of a wind turbine blade root in the form of a heterogeneous laminated plate is sim...

A vibration based damage identification algorithm is implemented to assess the damage of a thin–walled composite structure. The structure analysed is a skin with stiffeners, as frequently applied in aircraft components. Both experimental and numerical studies on a single composite skin–stiffener structure showed that the modal strain energy damage index (MSE–DI) algorithm is a suitable method f...

Delamination is a critical form of failure in composite laminates which is partitioned into a combination of three pure modes namely; opening, shearing and tearing (modes I, II and III respectively). Each fracture mode contributes to the total energy required for delamination growth, due to a combination of the different damage mechanisms that occur under each mode 1-2 . To formulate reliable m...

Drilling carbon/epoxy laminates is a common operation in manufacturing and assembly. However, it is necessary to adapt the drilling operations to the drilling tools correctly to avoid the high risk of delamination. Delamination can severely affect the mechanical properties of the parts produced. Production of high quality holes with minimal damage is a key challenge. In this paper, delamination...