When a polymer film that is weakly attached to a rigid substrate is exposed to solvent, swelling-induced compressive stress nucleates buckle delamination of the film from the substrate. Surprisingly, the buckles do not have a sinusoidal profile, instead, the film near the delamination buckles slides toward the buckles causing growth of sharp folds of high aspect ratio. These folds do not result...

Thermal barrier coating (TBC) systems are susceptible to delamination failures in the presence of a large thermal gradient. These failures, which occur within the TBC layer, are very different in character from those associated with the thermally grown oxide. Three possible causes of internal delamination are analyzed. In all cases, the thermomechanical properties of the TBC are allowed to vary...

This paper describes the experimental investigation on the effect of ply thickness on the first ply failure, delamination, and the subsequent final failure of graphite/epoxy composite laminates. The laminates considered in this paper are a cross-ply and two quasi-isotropic laminates containing thin plies in the desired interface. The onset of the first ply failure and delamination, and the stre...

Isogeometric cohesive elements are presented for modeling two and three dimensional delaminated composite structures. We exploit the knot insertion algorithm offered by NURBS (Non Uniform Rational B-splines) to generate cohesive elements along delamination planes in an automatic fashion. A complete computational framework is presented including pre-processing, processing and post-processing. Th...

Abaqus/Standard simulation of Lamb waves in smart composite plates is investigated for detecting delamination type damage. Composite plates typical of aerospace structures are used and a PZT actuator is surface bonded to excite Lamb waves. Abaqus model of composite plate uses layered solid elements. Piezoelectric (PZT-5H) actuator is modeled using piezoelectric elements that have both displacem...

Original scientific paper This paper has presented and discussed machinability in the drilling of SMC (Sheet Mould Compound) A-Class composite materials using Taguchi's DoE method. The thrust forces, surface roughness and push-out peel-up delamination behaviour in drilling process for glass fibre reinforced SMC composites have been evaluated. The experimental results and the contribution ratio ...

Glass Fiber Reinforced Plastic composites have an increased application in recent days, due to its enhanced structural, mechanical and thermal properties. The heterogeneous nature of this kind of materials makes complications during machining operations. Drilling of holes in GFRP becomes almost unavoidable in fabrication. However, drilling is a common machining practice for assembly of componen...

Thin films, used in various applications and devices, must strongly adhere to their substrates. Due to various processing and storage environments that devices can be exposed to, water may be introduced into the system. If residual stresses are present in a thin film, delamination propagation can be driven by water without the assistance of an externally applied mechanical force. It is extremel...

The delamination process in notched composite plates under flexural loading has been investigated using finite element analysis. Cohesive elements implemented in the commercial finite element package ABAQUS have been used in the region around the drilled-hole, and positioned between layers where delamination was observed during experiments presented in an accompanying paper. The delamination in...