An effort is made to gain insight on the effect of carbon nanotubes (CNTs) on the impact response of carbon fiber reinforced composites (CFRs) under low velocity impact. Certain amount of CNTs could lead improvements in mechanical properties of composites. In the present investigation, ABAQUS/Explicit finite element code (FEM) is employed to investigate various damages modes of nano composites ...

In this chapter some of the standard procedures for delamination testing of unidirectional polymer composites will be examined. The main objective is to explore the possibilities of applying the standard testing methods to interlayer toughened composites and to establish parameters which may influence fracture toughness measurements. Existing standards for mode I and mode II delamination testin...

Hole drilling operations are common in fibre reinforced plastics FRP’s to facilitate fastener assembly to other parts in more complex structures. As these materials are non-homogeneous, drilling causes some damages, like delamination, for example. Delamination can be reduced by a careful selection of drilling parameters, drill material and drill bit geometry. In this work two types of laminates...

In this work, the ultrasonic signals are modelled as a superposition of many Gaussian echoes with unknown parameters. The detection of ultrasonic echoes using Maximum A Posteriori estimation principle, based on the prior knowledge of the spectral characteristic of the ultrasonic transducer, has been used in order to estimate the unknown parameters. A simulation study validated by experimentatio...

Exchange of the chloride anion intercalated in [LiAl2(OH)6]Cl.nH2O with a range of surfactants is reported. Attempts to delaminate (or exfoliate) the surfactant-exchanged intercalates, where the surfactant was an alkyl sulfate, were unsuccessful. In contrast, delamination of the layered double hydroxides [LiAl2(OH)6][C12H25C6H4SO3.nH2O] and [LiAl2(OH)6][C8H17C6H4SO3.nH2O] was successful. The ne...

This article reports the development of a novel embedded acoustic waveguide sensor concept for monitoring the curing process and online health of composite structures. A sleevedwaveguide embedded in the composite is proposed to confine guidedwaves in one dimension, with leakage to the surroundingmedia only through specially created openings, thus enhancing the capability to inspect large struct...

Impact resistance and damage tolerance remain major concerns in the design of laminated composite structures. Impact on flat panels has been the subject of extensive experimental and theoretical studies [1]. The work on curved panels is more limited although most laminates in aircraft wings and fuselages, as well as in other vehicles, are more or less curved. The existence of a delamination thr...

drilling is one of the main machining processes carried out in the assembly stage of automobile manufacturing and aerospace components. generally, delamination is considered as a major problem during drilling of composite materials. in this paper, the effects of feed rate, cutting speed and drill point angle on thrust force and delamination factor have been studied by using full factorial desig...

An ultrasonic feature scan imaging system used for testing delamination flaw probably existing in the bimetal rotor clad layer was studied and developed. The bimetal rotor with nine column holes can be tested automatically. All the wave train of testing result will be saved in computer for post processing. There are various imaging modes including depth imaging and amplitude imaging, to find de...