De toepassing van schade-onderzoek in de luchtvaart

Following an introduction about the methods of failure smalysis the present paper illustrates by meaJis of actual case histories the role of service failure analysis in defining new inspection procedures and the adapting of existing ones. It appears that in some cases this leads to a different design or choice of material. The examples are all...

The effect of sheet edge working on the fatigue life under flight-simulation loading

Fatigue tests under flight-simulation loading have been performed on unnotched Alclad 2024-T3, anodised 2.0 mm thick sheet specimens, manufactured according to several machine-shop processes applied in the air craft industry. From the results it appears that milling is preferable to stamping. Rounding off the edges is also advantageous. The...

Reliability of nondestructive inspection

This report describes the concept of reliability of nondestructive inspection (NDI) and reviews the different aspects involved. First, the probability of detection (POD) of flaws in flawed specimens is discussed. To provide a measure of confidence in an estimated POD, lower botind values of this probability at a given confidence level are...

Defects and thermal stability of nanothin Cu films on Mo and Ta

In situ thermal helium desorption spectrometry (THDS) has been used to characterize defects and thermal stability of nanothin Cu films (0.5-30 nm) deposited on Mo and Ta by electron beam evaporation in ultrahigh vacuum. The substrates used were Mo(110), Mo(100), polycrystalline Mo, Ta(110) and Ta(100). Cu/Mo and Cu/Ta are heteroepitaxial systems...

Main functional elements having defects of illegal residential buildings: The case of Cova da Moura district

The purpose of the paper is to describe the main functional elements with defects in illegal residential buildings. Three research questions are addressed: What are the main functional elements with defects in buildings and in dwellings? What are the main defects found? In which way these defects affect the use of buildings? The defects were...

Inverse scattering solution for the spatially heterogeneous compliance of a single fracture

Characterizing the spatially heterogeneous fracture compliance through use of elastic waves has the potential to illuminate the hydraulic and mechanical properties along a fracture. We formulate the inverse scattering problem to estimate the heterogeneous compliance distribution along a single fracture embedded in a homogeneous background. For...

Test Code Quality and Its Relation to Issue Handling Performance

Automated testing is a basic principle of agile development. Its benefits include early defect detection, defect causelocalization and removal of fear to apply changes to the code. Therefore, maintaining high quality test code is essential. This study introduces a model that assesses test code quality by combining source code metrics that...

Test Code Quality and Its Relation to Issue Handling Performance

Automated testing is a basic principle of agile development. Its benefits include early defect detection, defect cause localization and removal of fear to apply changes to the code. Therefore, maintaining high quality test code is essential. This study introduces a model that assesses test code quality by combining source code metrics that...

Lu2O3-based storage phosphors. An (in)harmonious family

Ceramics of Lu2O3 activated with either Tb3+ or Pr3+ and co-doped with one of the transition metal ions – Ti, Hf or Nb – were investigated for their energy storage properties. Photoluminescence, thermoluminescence (TL) and optically stimulated luminescence spectra were recorded and discussed together with thermoluminescent glow curves. The Pr3+...

Migration of Open Volume Deficiencies in Hydrogenated Amorphous Silicon during Annealing

The nanostructure of hydrogenated amorphous silicon (a-Si:H) is studied by means of doppler broadening positron annihilation spectroscopy (DB-PAS) and Fourier transform infrared (FTIR) spectroscopy. The evolution of open volume deficiencies is monitored during annealing, demonstrating that small vacancies and other small vacancy clusters that...

Non-destructive testing investigation of gaps in thin Glare laminates

The manufacturing of Fibre Metal Laminates, consisting of alternating layers of pre-preg fibre and metal is complex, and defects can be introduced during manufacturing. The automation of the manufacturing steps is vital for future Glare production, and specific defects have to be considered. Among them, gaps between pre-preg plies represent a...

Modeling and Understanding the Compact Performance of h-BN Dual-Gated ReS₂ Transistor

In this study, high-performance few-layered ReS₂ field-effect transistors (FETs), fabricated with hexagonal boron nitride (h-BN) as top/bottom dual gate dielectrics, are presented. The performance of h-BN dual gated ReS₂ FET having a trade-off of performance parameters is optimized using a compact model from analytical...

Insights into the effect of susceptor rotational speed in CVD reactor on the quality of 4H-SiC epitaxial layer on homogeneous substrates

In this work, 4H-SiC homoepitaxial layers were grown on 4°off-axis substrates at different susceptor rotation speeds by using a hot-wall horizontal CVD reactor. The effect of different susceptor rotation speed on the quality of 4H-SiC epitaxial layers in terms of thickness, thickness uniformity, crystallinity, surface morphology and...

A multiscale consolidation model for press molding of hybrid textiles into complex geometries

Modeling the consolidation of fiber-reinforced thermoplastic composites at the part level presents a formidable computational challenge due to the multi-scale nature of the process. In this article, a method to bypass the multi-scale problem by homogenizing the micro scale and describing the medium with characteristic parameters is described....