In this study, the pitting type of corrosion growth characteristics, fatigue crack initiation and propagation behavior; axial fatigue tests were carried out on precipitation hardened martensitic Custom 450 steel in the air and 3.5wt% NaCl solution. Using the ratio of the depth to the half-width of the pits; (a/c)= 1.5±0.2 the corrosion pit depth growth law was obtained as a function of stress a...

BACKGROUND/PURPOSE Dental rotary instruments can be applied in multiple conditions of canals, but unpredictable fatigue fracture may happen. This study evaluated the fatigue lives of two batches of nickel-titanium (NiTi) dental rotary files operating in clinically simulated root canals. METHODS Single-step cyclic fatigue tests were carried out to assess the performance of two batches of NiTi ...

Buckling restrained braced frames (BRBFs) for seismic load resistance have been widely used in recent years. One of the key requirements for a buckling restrained brace is to sustain large plastic deformations under severe ground motions. The core of a buckling restrained brace is prone to fatigue fracture under cyclic loading. The earthquake induced fracture type of the core plate in a bucklin...

Self-healing polymers, based on microencapsulated dicyclopentadiene and Grubbs' catalyst embedded in the polymer matrix, are capable of responding to propagating fatigue cracks by autonomic processes that lead to higher endurance limits and life extension, or even the complete arrest of the crack growth. The amount of fatigue-life extension depends on the relative magnitude of the mechanical ki...

Vibration fatigue test and analysis methodology for flip chip solder joint fatigue life assessment have been developed by performing vibration tests with constant G-level and varying G-level input excitation. The linear cumulative damage analysis method (Miner’s rule) predicts non-conservative result for vibration fatigue life of flip chip solder joint. Finite element analysis (FEA) using a glo...

The corrosion fatigue performance of high-strength bolt was studied. Based on the fracture mechanics theory and the Gerberich-Chen formula, the high-strength bolt corrosion fracture crack model and the fatigue life model were established. The high-strength bolt crack depth and the fatigue life under corrosion environment were quantitatively analyzed. The factors affecting high-strength bolt cor...

background: fatigue is one of the most common symptoms in primary care that adversely affects work, family life, and social relations. the purpose of this study was to survey the relationship between work schedule and fatigue among the emergency personnel of isfahan, iran using the checklist individual strength (cis) standard method in 2010. methods: this cross-sectional study was performed on ...

The e ect of adding a superimposed high-frequent strain load, denoted as a high-cycle fatigue strain component, upon a strain-controlled thermomechanical fatigue test has been studied on a compacted graphite iron ENGJV-400 for di erent thermo-mechanical fatigue cycles and high-cycle fatigue strain ranges. It is demonstrated that the successive application of an high-cycle fatigue load has a con...

The purpose of the study is to show in which trimester of pregnancy is fatigue more common among working women, and whether or not there is any relationship between fatigue rate and educational level, income, etc. This is a longitudinal study. From the total number of patients who came to Zeinab University Hospital, 100 completed a demographics 50 item questionnaire and the numerical ratin...