Interfacial delamination is the major reliability issue of Quad Flat No-lead (QFN) packages under the JEDEC-MSL preconditioning and reflow process. Failures will occur when the hygrothermal stress exceeds the interfacial strength. Simulation based on finite element model is a popular method for studying the failure mechanism. However, the non-accurate material properties and lack of experiment ...

With the rapid development of Earth observation technologies, raster data has become the main Geographic Information System (GIS) data source. GIS should be able to manage and process huge raster data sets. In this paper, the problem of 3-dimensional visualization of huge DEM data sets and its corresponding image data sets in GIS was addressed. A real-time delamination method based on raster ch...

In this paper, a distant acoustic-laser NDE technique is proposed, utilizing a high powered standoff parametric acoustic array (PAA) and laser Doppler vibrometry (LDV), for the detection of debonding and delamination in multi-layer composite systems. Fiber-reinforced polymer wrapped concrete cylinder specimens with artificial defect were manufactured and used in the validation of the technique....

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...