The Welding in cold formed areas is not only an open question for statically loaded sections (brittle fracture) but also for dynamically loaded structures (fatigue resistance). A lot of structures are subjected to dynamic loadings and unfortunately very little information about the influence of welding in the cold formed areas on fatigue resistance is available. In order to establish the fatigu...

The prediction of fatigue life of metal welded joints plays an important role at lower manufacturing costs and reduces accidents for engineering materials, the response of metal welded joints to fatigue properties has highly non-linear, so it is difficult to establish an accurate theoretical model using traditional method to predict its fatigue life. It is appropriate to consider modeling metho...

In order to successfully implement reliable Flip Chip packaging technology, it is desirable to ensure solder fatigue as the limiting mechanical failure mechanism. Doing so enables the packaging engineer to design to specific reliability standards, as solder fatigue is a known and predictable failure mechanism. Indeed, other Flip Chip failure modes such as silicon fracture and underfill delamina...

PURPOSE/OBJECTIVES To examine how attentional fatigue changed from the time of simulation to four months after the completion of radiation therapy and to investigate whether specific variables predicted initial levels and trajectories of attentional fatigue. DESIGN Descriptive, longitudinal study. SETTING Two radiation therapy departments. SAMPLE 73 women with breast cancer who received p...

OBJECTIVE The effects of fatigue on multiple-task performance were explored through computational cognitive modeling. BACKGROUND Fatigue typically has a negative impact on human performance. Biomathematical models exist that characterize the dynamics of human alertness, but the link between alertness and in situ performance on specific tasks is tenuous. Cognitive architectures offer a princip...

Despite decades of study, the atomic-scale mechanisms of fatigue crack growth remain elusive. Here we use the coupled atomistic–discrete dislocation method, a multiscale simulation method, to examine the influence of dislocation glide resistance on near-threshold fatigue crack growth in an aluminum alloy. The simulations indicate that the threshold increases with an increase in dislocation glid...

Inter-individual differences in performance impairment from sleep loss are substantial and consistent, as demonstrated and quantified here by means of the intraclass correlation coefficient (ICC) in two laboratory-based sleep deprivation studies. There is an urgent need, therefore, to consider inter-individual variability in biomathematical models of fatigue and performance, which currently tre...

Title of Document: DEVELOPMENT OF FATIGUE MODELS FOR COPPER TRACES ON PRINTED WIRING ASSEMBLIES UNDER QUASI-STATIC CYCLIC MECHANICAL BENDING. Daniel M Farley, Doctor of Philosophy, 2010 Directed By: Professor Abhijit Dasgupta Department of Mechanical Engineering This dissertation investigates the fatigue durability of copper (Cu) traces on printed wiring assemblies (PWAs) under quasi-static cyc...