in this paper, three-dimensional modeling of the fatigue crack growth profiles was performed in a simple riveted lap joint. simulation results showed that mode i was dominated on the one side of the plates and the crack straightly grew on this side, while the other side of the plates was in a mixed-mode condition and the crack propagation path was not straight on this side. afterward, the fract...

Title of Document: AN ANALYTICAL APPROACH FOR FATIGUE LIFE ESTIMATION OF COPPER TRACES FOR DESIGN OPTIMIZATION IN ELECTRONIC ASSEMBLIES. Sandeep Menon, Doctor of Philosophy, 2015 Directed By: Professor Michael G. Pecht, Department of Mechanical Engineering This dissertation investigates the durability of the copper traces using experimental results from a fully reversed four point bend test and...

We investigated whether impaired sarcolemmal excitability causes severe fatigue during repeated tetani in isolated mouse skeletal muscle. Slow-twitch soleus or fast-twitch extensor digitorum longus (EDL) muscles underwent intensive stimulation (standard protocol: 125 Hz for 500 ms, every second, parallel plate electrodes, 20 V, 0.1-ms pulses). Interventions with altered stimulation characterist...

Operator fatigue and time-of-day induced variations in cognitive effectiveness can lead to lapses in attention, slowed reactions, and impaired reasoning and decision-making that has been shown to contribute to accidents, incidents and errors in a host of industrial and military settings. During the past three years, the US Air Force has sponsored the development of a model of human fatigue and ...

In ergonomics and biomechanics, muscle fatigue models based on maximum endurance time (MET) models are often used to integrate fatigue effect into ergonomic and biomechanical application. However, due to the empirical principle of those MET models, the disadvantages of this method are: 1) the MET models cannot reveal the muscle physiology background very well; 2) there is no general formation f...

We propose the hypothesis that soleus muscle function may provide a surrogate measure of functional capacity in patients with heart failure. We summarize literature pertaining to skeletal muscle as a locus of fatigue and present our recent findings, using in vivo imaging in combination with biomechanical experimentation and modeling, to reveal novel structure-function relationships in chronic h...

Approximately 30% of breast cancer survivors report persistent fatigue of unknown origin. We have previously shown that cancer-related fatigue is associated with alterations in immunological parameters and serum cortisol levels in breast cancer survivors. The current study examined the diurnal rhythm of salivary cortisol in fatigued and non-fatigued breast cancer survivors. Salivary cortisol me...

Intelligent tower crane has large structure deadweight. The service life of the whole machine is dependent on the life of the structure. As a result, the metal structure should be designed by using correct and reasonable methods to obtain excellent fatigue properties. And it can guide the design, manufacturing, use and maintenance process for crane. And it has great significance to prevent the ...

Driver fatigue is an important contributor to road accidents, and fatigue detection has major implications for transportation safety. The aim of this research is to analyze the multiple entropy fusion method and evaluate several channel regions to effectively detect a driver's fatigue state based on electroencephalogram (EEG) records. First, we fused multiple entropies, i.e., spectral entropy, ...