Many parts of the insect exoskeleton experience repeated cyclic loading. Although the cuticle of insects and other arthropods is the second most common natural composite material in the world, so far nothing is known about its fatigue properties, despite the fact that fatigue undoubtedly limits the durability of body parts in vivo. For the first time, we here present experimental fatigue data o...

Background. This study investigated the effects of short-duration high-intensity simulation of soccer fatigue on the dynamic balance and isokinetic strength of the lower limbs in youth soccer players. Methods. Thirty-nine youth soccer players completed a high-intensity fatigue simulation in 5-min. The participants performed tests on dynamic balance and isokinetic strength before the fatigue si...

Respiratory muscle strength and endurance is reduced in patients with congestive heart failure, making these patients susceptible to diaphragmatic fatigue during exercise. In order to determine whether or not contractile fatigue of the diaphragm occurs in patients with congestive heart failure following intense exercise, twitch transdiaphragmatic pressures (twitch Ptdi) were measured during unp...

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 microstructure and mechanical properties of Fe-0.85Mo-Ni powder metallurgy (P/M) steels were investigated as a function of sintered density. A quantitative analysis of microstructure was correlated with tensile and fatigue behavior to understand the influence of pore size, shape, and distribution on mechanical behavior. Tensile strength, Young’s modulus, strain-to-failure, and fatigue stren...

This study investigates how shape optimisation affects the ultimate fatigue strength of a mechanical part. The mechanical part chosen for this investigation is an axle guard of running gear elements of the Hccrrs 2x2 axle car-carrying wagon. The static and fatigue strength analysis procedure according to the UIC 517 standard and numerical methods have been applied. Material properties were dete...

In this research, the influence of bolt preload on the fatigue strength of 2024-T3 aluminium alloy double lap bolted joints has been studied experimentally and numerically. To do so, three sets of the specimens were prepared and each of them subjected to tightening torque of 1,2.5 and 5 N-m and then fatigue tests were conducted under various cyclic axial load levels. In the numerical method, th...

Resistance training (RT) is the main method of exercise for improving strength and skeletal muscle mass (i.e., muscle hypertrophy; ACSM, 2009). In order to promote such adaptations, high-intensity resistance training (HI-RT) with loads above 60% of one repetition maximum (1-RM) are typically recommended (ACSM, 2009). To further maximize increases in strength and muscle hypertrophy, it has been ...

in this research, the influence of bolt preload on the fatigue strength of 2024-t3 aluminium alloy double lap bolted joints has been studied experimentally and numerically. to do so, three sets of the specimens were prepared and each of them subjected to tightening torque of 1,2.5 and 5 n-m and then fatigue tests were conducted under various cyclic axial load levels. in the numerical method, th...