BACKGROUND: Muscle fatigue can be defined as the failure of a muscle to maintain a reasonably expected force output. The multivariate approach to fatigue assessment is used because the multiple (EMG) feature provides more information than anyone. OBJECTIVE: This study presents a method of assessing muscle fatigue during endurance testing at 50% maximal voluntary contraction (MVC) using electro...

Granite is a typical crystalline material, often used as a building material, but also a candidate host rock for the repository of high-level radioactive waste. The petrographic texture-including mineral constituents, grain shape, size, and distribution-controls the fracture initiation, propagation, and coalescence within granitic rocks. In this paper, experimental laboratory tests and numerica...

Shot peening has been developed to enhance the fatigue strength of metallic parts. However, improper shot peening can decrease the fatigue life due to induced high surface roughness and residual tensile stress. The effectiveness of the manual shot peening process is accomplished by the control of the process parameters to provide a uniform intensity and coverage throughout the work piece. This ...

The micro/nano structural evolution before and after tensile loading, fatigue and ultimately, failure has been studied by Raman microspectroscopy for PA66, PP, PBO and PET single fibres and precursors, using two probes : low wavenumber collective modes at <150 cm as representative of the crystalline and amorphous chains and stretching and bending modes, as representative of the C-C bond local b...

Waste fibers produced from manufacturing processes are a byproduct commonly deposited in storing yards and/or landfills and thus results in many serious environmental problems in Iran. If these waste materials could be advantageously put to practical use in any application, it would reduce the burden on the environment and landfills. This paper compares the performance of the stone matrix aspha...

Tensile strength is an important parameter in many engineering applications. In loess slopes, for instance, it governs the development and propagation of tension cracks that usually ultimately lead to crack–sliding toppling failures, which are among most common modes slope failure Loess Plateau China. Reliable measurement tensile geomaterial therefore a necessity. Commonly used methods have lim...

A new mixed-mode threshold stress intensity factor is developed using a critical plane-based multiaxial fatigue theory and the Kitagawa diagram. The proposed method is a nominal approach since the fatigue damage is evaluated using remote stresses acting on a cracked component rather than stresses near the crack tip. An equivalent stress intensity factor defined on the critical plane is proposed...

Abstract The uniaxial tensile test investigated the fatigue performance of DP780 steel without pre-strain and with 5% 10% pre-strain. Topography fractured surfaces was observed to study relationship between performance. results showed that specimens would affect steel. It cause an increase in life when stress comparatively high less than 100,000 cycles. However, reduced level low, more Pre-stra...