The primary factors governing the behavior in the long lifetime regime of turbine engine materials are discussed. These factors are based on a study of fatigue lifetime distributions and underlying mechanisms in a number of materials, including titanium alloys, nickel-base superalloys, and  TiAl based alloys. A hypothesis of fatigue variability is described, and appears to explain the various ...

A typical dynamometer drive shaft was damaged during its working condition. This failure was repeated in four cases. In the present article, a failure analysis of a dynamometer drive shaft has been performed. To analyze the failure, the material investigation was carried out by scanning electron microscopy (SEM) images. Additionally, the micro-structure of the failed coupling shaft was photogra...

A methodology is evaluated to predict the probability of specimen failure with subsequent fatigue, after a short surface crack has been detected in Al 2219-T851 alloy. Cracks are detected and tracked to failure using optical microscopy. Predictions of remaining lifetime distributions are made with a i~onte Carlo procedure in conjunction with growth laws which model the effect of grains of diffe...

Almost all structural applications of adhesive joints will experience cyclic loading and in most cases this will irregular in nature, a form of loading commonly known as variable amplitude fatigue (VAF). This paper is concerned with the VAF of adhesively bonded joints and has two main parts. In the first part, results from the experimental testing of adhesively bonded single lap joints subjecte...

The present paper describes a benchmarking programme to compare different lifetime prediction methodologies. Lifetime prediction is still a complex task and the results depend on many factors. Thus, it is very important to know which factors have a decisive effect on the results. The main objective of this investigation is not to proof the validity of a certain prediction model, but to quantify...

Accurate lifetime prediction of lithium-ion batteries is a great challenge for the researchers and engineers involved in battery applications in electric vehicles and satellites.  In this study, a semi-empirical model is introduced to predict the capacity loss of lithium-ion batteries as a function of charge and discharge cycles, operational time, and temperature. The model parameters are obtai...