| Damage detection using guided Lamb waves is an important tool in Structural health Monitoring. In this paper, we outline a method of obtaining Lamb wave modes in composite structures using two dimensional Spectral Finite Elements. Using this approach, Lamb wave dispersion curves are obtained for laminated composite structures with different fibre orientation. These propagating Lamb wave modes...

The effect of stitching on mode I and mode II strain energy release rates for debond configurations is studied using an analysis based on plate finite elements and the virtual crack closure technique. The stitches were modeled as discrete nonlinear fastener elements with a compliance determined by experiment. The axial and shear behavior of the stitches was considered with both the compliances ...

Although defective, commercially-available, CVDgrown, multi-walled carbon nanotubes are widely used for polymer nanocomposites due to their availability and low cost. However, to use these materials effectively, they must be disentangled, and chemically modified in order to produce high quality composites. This paper shows that such nanotubes can be disentangled by cutting; abrupt, repeated exp...

A numerical procedure for the design of impact damage resistant composite laminated structures is proposed in the present paper. This procedure, based on probabilistic analyses, is able to support the design of complex composite laminated structures by accounting for the scatter in composite materials’ mechanical properties (related to the mutable environmental conditions experienced by an airc...

statement of problem: the restoration of the teeth should have enough ability to withstand masticator forces while preserving as much tooth structure as possible. purpose: the purpose of this study was to compare the effects of light-heat cured composite with light cured composite restorations on fracture resistance of the restored teeth. materials and methods: forty healthy maxillary premolar ...

the influence of nanoclay on the impact damage resistance of glass fiber–epoxy composites has been investigated using high-velocity repeated ice impact tests. the incorporation of nanoclay into epoxy enhances the impact resistance of the composites. the impact of ice is a realistic scenario for composite structures such as aircraft fuselages, wing skins and fan blades and it is not a completely...

An approach for decreasing costs in lightweight structures using FRP composite materials is applied considering hybrid construction where expensive and high-stiffness materials are used together with inexpensive and low-stiffness material. So, a Multi-objective Memetic Algorithm (MOMA) searching Pareto-optimal front is proposed. The trade-off between minimum weight/sustainable costs and minimum...

In this study, discrepancies between the free vibration of fiber-metal laminate (FML) and composite cylindrical shells reinforced by carbon nanotubes (CNTs) based on Love’s first approximation shell theory have been considered by beam modal function model. The representative volume elements consist of three and four phases for composite and FML structures, respectively, which include fiber, CNT...

Due to their light weights and high load carrying capacities, composite structures are widely used in various industrial applications especially in aerospace industry. Stiffening ribs are the main features of lattice type composite structures. Strength to weight ratio is known to be as one of the most critical design parameter in these structures. In this study, the effect of some parameters su...

Abstract: The study is to propose the local damage indices of composite frame structures consisting of high-strength concrete columns confined by continuous compound spiral ties and steel beams (CCSTRCS), the local damage indices would lay a foundation for the study of the overall damage indices for composite CCSTRCS frame. The Mehanny damage model has been modified to predict the local damage ...