Solder joint reliability of SMT components connected to printed circuit boards is well documented. However, much of the testing and data is related to high-strain energy thermal cycling experiments relevant to product qualification testing (i.e., -55C to 125C). Relatively little information is available on low-strain, high-cycle fatigue behavior of solder joints, even though this is increasingl...

This study describes the fatigue behaviour of newly developed all-polypropylene (all-PP) tapes and woven composites [1], with reference to the composite processing conditions, testing temperature and comparison to commercial alternatives. The possible damage development mechanisms are also part of the present paper. All-PP tapes used in this study are highly oriented (90 wt% oriented phase) and...

Abstract: To ensure the rail transportations safety, evaluation of fatigue behavior of the rail steel is necessary. High cycle fatigue behaviour of a rail steel was the subject of investigation in this research using fracture mechanics. Finite element method (FEM) was used for analyzing the distribution of the stresses on the rail, exerted by the external load. FEM analysis showed that the ...

OBJECTIVES This study compared the cyclic fatigue resistance of nickel-titanium (NiTi) files obtained in a conventional test using a simulated canal with a newly developed method that allows the application of constant fatigue load conditions. MATERIALS AND METHODS ProFile and K3 files of #25/.06, #30/.06, and #40/.04 were selected. Two types of testing devices were built to test their fatigu...

CONTEXT The biology of fatigue and depression in cancer patients is poorly understood. Hypotheses regarding cytokines and growth factors related to sickness behavior and disruption of circadian signaling have been proposed. OBJECTIVES We prospectively examined proinflammatory cytokines (e.g., sickness behavior model) and epidermal growth factor receptor (EGFR) ligands (e.g., circadian disrupt...

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...

A review of several past studies clearly shows the effect of reduced air voids on improved fatigue and rutting performance of asphalt mixtures, both in the laboratory and field. Depending on mix type and experiment (which included constant-stress bending beam fatigue testing and field results from WesTrack), fatigue performance improved between 8.2 and 43.8% with a 1% decrease in air voids. Lik...

Ultrahigh molecular weight polyethylene (UHMWPE) fatigue is a critical factor affecting the longevity of total knee replacement (TKR) bearings. With the increased need for laboratory studies to mimic near in vivo conditions for accurate characterization of material performance, the present study investigated the role of hyaluronic acid (HA) in testing lubricant on the crack growth response of U...

The purpose of this study was to develop an algorithm to classify muscle fatigue content in sports related scenarios. Mechanomyography (MMG) signals of the biceps muscle were recorded from thirteen subjects performing dynamic contractions until fatigue. For training and testing purposes, the signals were labeled in two classes (Non-Fatigue and Fatigue). A genetic algorithm was used to evolve a ...