An experimental and numerical investigation of sphere impact on alumina ceramic

In this study, the impact of a steel spherical projectile on an alumina ceramic is considered. New experimental and numerical results are presented and analysed. Numerical results are obtained using the Finite Element Method and the upgraded viscosity regularized Johnson-Holmquist-2 constitutive model to describe the ceramic material behaviour....

Modelling the mechanical response of adobe components under uniaxial loading

Performance of all-Polypropylene composites at LNG temperatures

In the small scale LNG infrastructure, composite materials are scarcely employed. Potentially, cost effective solutions for LNG applications could be developed thanks to the advantages of composite materials over metals such as weight savings, design flexibility and recyclability. The research presented in this paper focuses on the mechanical...

Understanding the transport phenomena leading to tarnishing of the reflecting silver layer causing reduced light output of LEDs

Evaluating vibration performance of a subsea pump module by full-scale testing and numerical modelling

Prior to subsea installation, a subsea system has to be tested to verify whether it performs in accordance with specifications and component specific performance evaluation criteria. It is important to verify that the assembled components work in accordance with the assumptions and design criteria used in the detailed engineering. These criteria...

Failure analysis in ITO-free all-solution processed organic solar cells

In this paper we discuss a problem-solving methodology and present guidance for troubleshooting defects in ITO-free all-solution processed organic solar cells with an inverted cell architecture. A systematic approach for identifying the main causes of failures in devices is presented. Comprehensive analysis of the identified failure mechanisms...

Remaining fatigue life time assessment of welded and braced side branches

High cycle fatigue failure is likely to occur when a rather undamped offshore installation is operated over a long period of time. Especially welded parts are vulnerable to fluctuating stress ranges, if the structural components, such as the small bore side branches, are loaded in resonance. In particular, the welded connections at e.g. tie-in...

In-situ tensile testing of propellant samples within SEM

A tensile module system placed within a FEI NovaNanoSEM 650 Scanning Electron Microscope (SEM) was utilized in this work to conduct in-situ tensile testing of propellant material samples. This tensile module system allows for real-time in-situ SEM analysis of the samples to determine the failure mechanism of the propellant material under tensile...

Structural unsafety revealed by failure databases

After several major structural incidents in the Netherlands, such as the collapse of five balconies in Maastricht in 2001 resulting in two fatalities, various initiatives have been started to improve structural safety. Research studies were initiated on the characteristics, causes and consequences of structural incidents. In this paper the...

Updating piping reliability with field performance observations

Flood defenses are crucial elements in flood risk mitigation in developed countries, especially in deltaic areas. In the Netherlands, the VNK2 project is currently analyzing the reliability of all primary flood defenses as part of a nationwide flood risk analysis. In this project, as in most other reliability analyses of flood defenses, prior...

Consequences of using the plane stress assumption for damage calculations in Crash analyses

Opschaling van maatschappelijk relevante ICT- toepassingen: Lessen uit de praktijk

Aan de hand van het Actieprogramma Maatschappelijke Sectoren en ICT heeft TNO in opdracht van het ministerie van Economische Zaken de praktijk rond opschaling verkend. Het rapport geeft een overzicht van de ontwikkelingen in de belangrijkste domeinen van het Actieprogramma (onderwijs, zorg, maatschappelijke veiligheid, jeugd en wijken), en geeft...

On the availability of a k-out-of-N system given limited spares and repair capacity under a condition based maintenance strategy

This paper considers a k-out-of-N system with identical, repairable components. Maintenance is initiated when the number of failed components exceeds some critical level. After a possible set-up time, all failed components are replaced by spares. A multi-server repair shop repairs the failed components. The system availability depends on the...

A composite plasticity model for concrete

A composite yield function is used to describe the behavior of plain and reinforced concrete in biaxial stress under monotonic loading conditions. A Rankine yield criterion is used to monitor the in-plane tensile stresses and a Drucker Prager yield function controls the compressive stresses. A good agreement with experimental data for biaxial...

Cost-effective and detailed modelling of compressor manifold vibrations

In systems with large reciprocating compressors, so-called compressor manifold vibrations can contribute to fatigue failure of the pipe system. These vibrations are excited by pulsation-induced forces and by forces generated by the compressor. This paper describes an advanced and accurate method for predicting vibration levels and cyclic...

Environmental stress cracking of PVC and PVC-CPE - Part III Crack growth

The fracture toughness of Polyvinylchloride (PVC) and PVC modified with 10% chlorinated polyethylene (PVC-CPE) was studied in vapour and in liquid environments by crack growth measurements on single-edge notch specimens under three-point bending at 23°C. In addition, some results obtained in air at lower temperatures are presented. The fracture...

Environmental stress cracking of PVC and PVC-CPE - Part II Failure mechanisms

The failure of unnotched PVC and PVC-CPE was studied in a number of vapour and liquid environments. The failure mechanisms observed are related to craze initiation and logarithmic craze growth. A model to explain the origin of the logarithmic craze growth is presented. The failure mechanism in air and in benzene and toluene vapours is ductile,...