APPROACH: Buckling driven delamination is difficult to control in experiments. Thus, the present study relies on numerical simulations using geometrically nonlinear finite element analysis as well as the softening foundation model, which is an adaptation of Winkler elastic foundation. Delamination fracture is modeled by a cohesive crack model. Dimensionless variables are used to cover the entir...

Electrical Resistance Tomography (ERT) offers a non-destructive evaluation (NDE) technique that takes advantage of the inherent electrical properties in carbon fiber reinforced polymer (CFRP) composites for internal damage characterization. This paper investigates a method of optimum selection of sensing configurations for delamination detection in thick cross-ply laminates using ERT. Reduction...

Inverse problems and inverse analyses, which deal with estimation of inputs or source from outputs or results, have been receiving increasing attention in various fields of science and engineering. A reasonable classification of the inverse problems is described. The nature of inverse problems and difficulties encountered in the inverse analyses are discussed. Typical inversion analysis schemes...

Delamination is one of the most common failure modes in composite structures. In particular, when the laminated composites are subjected to compressive loads, delamination becomes a constraint in the design process. In this study, the system is modeled as a plate supported by an elastic foundation. The elastic adhesive layer between the buckled sublaminates is represented by some parallel sprin...

The characteristics of carbon fibre reinforced laminates had widened their use, from aerospace to domestic appliances. A common characteristic is the need of drilling for assembly purposes. It is known that a drilling process that reduces the drill thrust force can decrease the risk of delamination. In this work, delamination assessment methods based on radiographic data are compared and correl...

Beside the twist drill, the effects of various drill geometries were rarely discussed in analytical fashion. This study presents a comprehensive analysis of delamination in use of various drill types, such as saw drill, candle stick drill, core drill and step drill. In this analysis, the critical thrust force at the onset of delamination is predicted and compared with the twist drill. © 2003 El...