BACKGROUND People with multiple sclerosis (MS) are encouraged to engage in exercise programs but an increased experience of fatigue may impede sustained participation in training sessions. A high number of movements is, however, needed for obtaining optimal improvements after rehabilitation. METHODS This cross-sectional study investigated whether people with MS show abnormal fatigability duri...

The reliability of welded structure can be evaluated through welding residual stress analysis and fatigue strength assessment. In this study, welding residual stresses of multi-pass dissimilar material welded joint between alloy 617 and 12Cr steel were analyzed numerically and experimentally. Fatigue strength was then assessed in the air. Based on results of welding residual stress analysis and...

Commercial transport aircraft are required to operate under the concept of damage tolerance. Because of the structural redundancy and the crack arrest capability, the current fleet of commercial aircraft was initially designed to have sufficient residual strength to sustain discrete source damage. However, fatigue damage during the life of an aircraft can significantly reduce the residual stren...

Ultrasonic peening treatment (UPT) as a method of severe plastic deformation was used to treat cruciform welded joints of Q345 steel. The application of UPT achieves material surface nanocrystallization of the peening zone, reduces stress concentration, and produces residual compressive stresses at the welded toe. Micro-structure, hardness, stress relief, S-N curve, and the fatigue fracture mec...

The three-dimensional model of 2500hp shale gas fracturing truck chassis frame was established and the natural frequency of the frame was obtained by modal analysis. Taking the displacement power spectrum density of a typical road as a random excitation, the random vibration response of frame was obtained by PSD module of finite element analysis software ANSYS. Based on the results of PSD analy...

statement of problem: the question about resistance of resin composites under rest in removable partial denture (rpd) is still unanswered. it is important to find the strongest material that withstands the applied stresses when used under rpd components. objectives: to evaluate and compare the fatigue behavior of amalgam and composite restorations used under the rest of the removable partial de...

in the present study, the mechanical properties and fracture mechanisms of two powder metallurgy low alloy steels, i.e. distaloy dh and distaloy hp, were investigated. all samples were sintered at 1120 ºc for 30 min in n2/h2 atmosphere. for evaluation of the effect of cooling rate on final properties, samples were cooled from sintering temperature with two different cooling rates. in addition, ...

BACKGROUND There are limited number of studies investigating extrapulmonary manifestations of bronchiectasis. The purpose of this study was to compare peripheral muscle function, exercise capacity, fatigue, and health status between patients with bronchiectasis and healthy subjects in order to provide documented differences in these characteristics for individuals with and without bronchiectasi...

This paper presents experimental research on the fatigue and post-fatigue static behaviour of reinforced concrete beams strengthened with glass or carbon fibre reinforced polymer (FRP) sheets placed either vertically or obliquely. All beams for fatigue tests were subjected to four-point bending for one million cycles with a frequency of 5 Hz. The results show that the FRP sheets can be used to ...

In this paper, the fatigue damage and lifetime of 2D SiC/SiC ceramic-matrix composites (CMCs) under cyclic fatigue loading at 750, 1000, 1100, 1200 and 1300 °C in air and in steam atmosphere have been investigated. The damage evolution versus applied cycles of 2D SiC/SiC composites were analyzed using fatigue hysteresis dissipated energy, fatigue hysteresis modulus, fatigue peak strain and inte...