Time to failure analysis of wood adhesives: a non-linear approach based on chemical reaction kinetics

Similar to wood, adhesives may exhibit duration of load effects. When loaded for longer periods of time, damage processes in the material may develop, eventually leading to failure. From wood research it is known that load level, temperature and relative humidity have an important influence on this behaviour. In general, higher stress levels,...

Failure Analysis of Two HP-Nb Heat-Resistant Tubes after 46,000 h Exposure to Reformer Service Conditions

This study presents a failure analysis in two reformer tubes used for hydrogen production in a petrochemical industry. These tubes (Tube A and Tube B) were made by the centrifugal casting of HP-Nb alloy in such a way that one contained titanium as a micro-element, and the other was free from titanium in its chemical composition. Although the two...

Investigation of Unclamped Inductive Switch Characteristics in 4H-SiC MOSFETs With Different Cell Topologies

To investigate the unclamped inductive switch (UIS) characteristics, 1200 V silicon carbide (SiC) planar MOSFETs with four cell topologies of linear, current sharing linear, square, and hexagon are designed and manufactured. The experimental platform was built and tested. The results show that the single pulse avalanche energy density of the...

Effects of different joint wall lengths on in-plane compression properties of 3D braided jute/epoxy composite honeycombs

To comply with the trend in the development of engineering materials towards lightweight, high strength, eco-friendly, sustainable, and multi-functional, a three-dimensional braided integrated composite honeycomb is designed. The effects of geometrical parameters particularly joint wall lengths on the in-plane mechanical behavior of the...

Rational hyperelastic modelling of elastic poured compound for the failure analysis of embedded rail system

The continuous homogeneous rail constraint of embedded rail system (ERS) is realized by the encapsulation of rails with the elastic poured compound (EPC) which is a composite material. Previous treatment of EPC as linear elastic material was insufficient in the failure analysis of ERS. In this work, a hyperelastic model is developed to...

A study on the failure of AISI 304 stainless steel tubes in a gas heater unit

This paper investigates a failure in convection section tubes of a gas heater unit in a petrochemical plant. Tubes are made of AISI 304 stainless steel. The failure is reported after 5 years of service at working temperature 500 °C. The failure is in the form of circumferential cracks in the vicinity of the weld. Various characterization...

Frequency Response of a Real Cable Network and its Impact on Field PD Measurements

Asset condition monitoring through Partial Discharge (PD) measurements is widely used for pre-emptive maintenance especially in cable networks. Several monitoring systems rely on measurements in the High Frequency (HF) band using wideband sensors when it comes to PD monitoring to have higher Signal to Noise Ratios (SNR), ignoring the radical...

Creep failure of reformer tubes in a petrochemical plant

This paper investigates a failure in HP-Mod radiant tubes in a petrochemical plant. Tubes fail after 90,000 h of working at 950 °C. Observed failure is in the form of excessive bulging and longitudinal cracking in reformer tubes. Cracks are also largely branched. The microstructure of service-exposed tubes was evaluated using optical and...

Electroluminescence and Dark Lock-In Thermography for the Quality Assessment of Metal-Wrap-Through Solar Devices

Imaging techniques, like electroluminescence and dark lock-in thermography, are valuable quality control tools as they yield quantitative and spatially resolved information about the device. In this paper, we isolated some of the conductive foil–cell interconnections of back-contact solar cells to study the appearance of these...

MIP Plasma Decapsulation of Copper-wired Semiconductor Devices for Failure Analysis

The majority of Integrated Circuit (IC) devices are encapsulated in wire-bonded plastic IC packages. Epoxy molding compound is used as the encapsulation material and gold was used as the bonding wire material. However, the increase of gold material price from 400 USD/ounce in year 2005 to 1400 USD/ounce in year 2013 results in a major cost issue...

Computational modelling of fibre-reinforced cementitious composites: An analysis of discrete and mesh-independent techniques

Failure patterns and mechanical behaviour of high performance fibre-reinforced cementitious composites depend to a large extent on the distribution of fibres within a specimen. A discrete treatment of fibres enables us to study the influence of various fibre distributions on the mechanical properties of the material. The numerical analysis of...

Failure of Engineering Artifacts: A Life Cycle Approach

Failure is a central notion both in ethics of engineering and in engineering practice. Engineers devote considerable resources to assure their products will not fail and considerable progress has been made in the development of tools and methods for understanding and avoiding failure. Engineering ethics, on the other hand, is concerned with the...

Faalkansanalyse van het zeetransport van tunnelelementen

Het wordt steeds moeilijker voor een tunnelproject een locatie te vinden voor het bouwdok voor de tunnelelementen. Het is daarom aantrekkelijk een bestaand bouwdok te gebruiken en de tunnelelementen over langere afstand te vervoeren, desnoods over zee. Om het transport van een tunnelelement over zee te bewerkstelligen zijn een aantal facetten...

Failure and cracking of Inconel 718 air supply manifold support rods: A service-related contribution to lEPG TA 31

In 1995 an air supply manifold support rod from a high-performance turbofan engine failed by bending fatigue. The rod material was Inconel 718, operating at about 550° in an air environment. Diagnostic aspects of the failure (fatigue in bending, Stage I and Stage II fatigue fracture characteristics, and interference colours due to fracture...

KADAM knowledge-based assistant for diagnosis in aircraft maintenance: Final report

Under contract with the Netherlands Agency for Aerospace Programs (NIVR), the National Aerospace Laboratory NLR has investigated the feasibility of knowledge-based systems to assists ground crews in corrective maintenance of complex aircraft systems. For this feasibility study, the Fokker airconditioning system was chosen as a representative...

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...

Tensile failure of unidirectional composite materials