Fatigue damage is considered to be one of the most critical phenomenon, contributing to the failure of an aircraft structure. Understanding the fatigue mechanism is essential for considering the different technical conditions that influence the fatigue life of structures. In recent years, fatigue tests are accelerated in order to reduce the testing time of materials/structures being developed, ...

To determine if objective evidence of autonomic dysfunction exists from a group of Gulf War veterans with self-reported post-exertional fatigue, we evaluated 16 Gulf War ill veterans and 12 Gulf War controls. Participants of the ill group had self- reported, unexplained chronic post-exertional fatigue and the illness symptoms had persisted for years until the current clinical study. The control...

The significance of strain measurement is obvious for the analysis of Fiber-Reinforced Polymer (FRP) composites. Conventional strain measurement methods are sufficient for static testing in general. Nevertheless, if the requirements exceed the capabilities of these conventional methods, more sophisticated techniques are necessary to obtain strain data. Fiber Bragg Grating (FBG) sensors have man...

Fatigue is a major limitation to the clinical application of functional electrical stimulation. The activation pattern used during electrical stimulation affects force and fatigue. Identifying the activation pattern that produces the greatest force and least fatigue for each patient is, therefore, of great importance. Mathematical models that predict muscle forces and fatigue produced by a wide...

Results are presented from an experimental program that recorded the outputs of strain gages mounted on two wheelchair frames (one manual, one power) as the wheelchairs were run on a double roller fatigue machine. Rectangular strain gage rosettes were attached to the frames near the cross tube center pin and on the side frame behind a front caster. Thirty data sets were recorded from each roset...

A major limiting factor to the longevity of prosthetic knee joints is fatigue crack damage of the polyethylene tibial insert. Existing methods to quantify fatigue crack damage have several shortcomings, including limited resolution, destructive testing approach, and high cost. We propose an alternative fatigue crack damage visualization and measurement method that addresses the shortcomings of ...