OBJECTIVES The effect of shot blasting treatment on the cyclic deformation and fracture behavior of a commercial pure titanium with two different microstructures; equiaxed (alpha-phase) and acicular (martensitic alpha'-phase) was investigated. METHODS Fatigue tests were carried out in artificial saliva at 37 degrees C. Cyclic deformation tests were carried out up to fracture and fatigue crack...

Bulk silicon is not susceptible to high-cycle fatigue but micron-scale silicon films are. Using polysilicon resonators to determine stress-lifetime fatigue behavior in several environments, oxide layers are found to show up to four-fold thickening after cycling, which is not seen after monotonic loading or after cycling in vacuo.We believe that the mechanism of thin-film silicon fatigue is ‘‘re...

OBJECTIVE The objective of this study is to compare the cyclic fatigue resistance of nine types of endodontic instruments of nickel-titanium. MATERIALS AND METHODS Five files of 25 mm of length of each group: Reciproc (RC) R25; WaveOne (WO) Primary; Unicone (UC) L25 25/0.06; K3XF 25/0.06; ProTaper Universal F2 (PTF2); ProTaper Next X2 (PTX2); Mtwo 25/0.06; BioRaCe 25/0.06; One Shape L25 25/0....

Durability of reinforced concrete (RC) structures is affected by certain environmental conditions and operational actions which can reduce their lifetime significantly. Among these actions, this paper proposes a stochastic model that accounts for the combined effects of chloride-induced corrosion, climate change and cyclic loading. Separately, corrosion leads to cross-section reduction, climate...

In this paper, the synergistic effects of stress rupture and cyclic loading on the strain response of fiber-reinforced ceramic-matrix composites (CMCs) at elevated temperature in air have been investigated. The stress-strain relationships considering interface wear and interface oxidation in the interface debonded region under stress rupture and cyclic loading have been developed to establish t...

Ratcheting-fatigue investigations have been carried out to understand the ratcheting-fatigue failure of carbon manganese steel (conforming to ASME specification of SA-333 Gr.6). Experiments have been conducted on pressurized pipe-elbow assembly subjected to reversible cyclic bending, to assess the failure mechanics owing to ratcheting-fatigue synergy. These studies are required to evaluate the ...

INTRODUCTION Cyclic loading of trabecular bone can lead to fatigue damage and increased risk of fracture in both young and the elderly populations. Fatigue damage processes in trabecular bone include reduction of elastic modulus and accumulation of residual strain. Development of models relating the above effects to the loading variables (stress, strain) is essential for a predictive understand...

The fatigue behavior of polyether ether ketone (PEEK) thermoplastic was investigated under uniaxial strain-controlled cyclic loading condition with various mean strains (Rε 1⁄4 0, 0.2, and 0.25). The mean stress responses of PEEK from all mean strain fatigue tests were found to be fully-relaxed. As a result, minimum mean strain effect on fatigue behavior of PEEK was observed. Fractography analy...

Static and fatigue data available in literature concerning carbon fiber reinforced composite laminates subjected tension-tension fatigue were re-elaborated in the framework of a two-parameter fatigue model explicitly accounting for the cyclic as well as the mean stress. The data were used to obtain the model parameters by best fitting procedures. A primitive statistical implementation of the mo...

The effect of fatigue on ZrCuAl amorphous metals induced by mechanical cyclic loading is investigated using inelastic neutron scattering and the pair density function analysis of neutron diffraction data. With cooling, the local atomic structure undergoes reorganization under fatigue that is directly related to the number of fatigue cycles. Also under fatigue, suppression in the atomic dynamics...