Practice for Strain-Controlled Axial-Torsional Fatigue Testing with Thin-Walled Tubular Specimens

2021 ◽  
Author(s):  
Keyword(s):  
Fatigue Testing ◽  
Torsional Fatigue ◽  
Thin Walled ◽  
Tubular Specimens

Accuracy of Multiaxial Fatigue Testing with Thin-Walled Tubular Specimens

2008 ◽  
pp. 103-103-12
Author(s):  
DF Lefebvre ◽  
H Ameziane-Hassani ◽  
KW Neale
Keyword(s):  
Fatigue Testing ◽  
Multiaxial Fatigue ◽  
Thin Walled ◽  
Tubular Specimens

A novel high-frequency fatigue testing methodology for small thin-walled structures in the HCF/VHCF regime

2021 ◽  
Vol 146 ◽  
pp. 106146
Author(s):  
Florian Himmelbauer ◽  
Michael Tillmanns ◽  
Gerhard Winter ◽  
Florian Gruen ◽  
Constantin Kiesling
Keyword(s):  
High Frequency ◽  
Fatigue Testing ◽  
Testing Methodology ◽  
Thin Walled Structures ◽  
Thin Walled

Effects of Prior Plasticity on Subsequent Creep of Type 316 Stainless Steel at Elevated Temperature

1986 ◽  
Vol 108 (1) ◽  
pp. 68-74 ◽  
Author(s):  
Y. Ohashi ◽  
M. Kawai ◽  
T. Momose
Keyword(s):  
Plastic Deformation ◽  
Stainless Steel ◽  
Creep Resistance ◽  
Tensile Direction ◽  
316 Stainless Steel ◽  
Plastic Prestraining ◽  
Axial Tensile ◽  
Thin Walled ◽  
Stress States ◽  
Tubular Specimens

Interaction between creep and plastic deformation was studied experimentally for type 316 stainless steel at 650°C, with special emphasis on creep behavior subsequent to plastic prestraining. In combined creep-plasticity experiments, thin-walled tubular specimens were first prestrained plastically in the axial tensile direction, and were subsequently subjected to constant stress creep under various multiaxial stress states with an identical effective stress. Furthermore, the variation in creep resistance due to the plastic prestrain was compared with that due to the same amount of creep prestrain. From the experimental results, it was found that creep resistance was markedly enhanced by the plastic prestrain and that the increase in the creep resistance depended on the amount and relative direction of the plastic prestrain. The creep resistance was increased more markedly by creep prestrain than the same amount of plastic strain.

scholarly journals Torsional and Bending Properties of V Taper 2H, ProTaper NEXT, NRT, and One Shape

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Soram Oh ◽  
Kee-Yeon Kum ◽  
Kwon Cho ◽  
Soo-Hyuk Lee ◽  
Seung-Hyun You ◽  
...  
Keyword(s):  
Thermal Treatment ◽  
Fatigue Resistance ◽  
Root Canal ◽  
Fatigue Testing ◽  
Bending Test ◽  
Niti Wire ◽  
Torsional Fatigue ◽  
Heat Treated ◽  
Bending Resistance ◽  
Cantilever Bending

Nickel-titanium (NiTi) rotary files have enabled efficient root canal preparations that maintain the canal center with fewer aberrations compared to hand files. However, NiTi rotary files are susceptible to fracture, which can thereby compromise root canal treatment. Therefore, NiTi files have been developed to enhance fracture resistance by modifying design and thermal treatment. The objective of this study was to compare the torsional fatigue resistance and bending resistance of NiTi files manufactured from different alloys and treatments. ProTaper NEXT X2 (PTN; M-wire), V taper 2H (V2H; controlled memory wire), NRT (heat-treated), and One Shape (OS; conventional alloy) instruments of tip size #25 were compared. Torsional fatigue was evaluated by embedding the 3 mm tip of each instrument (N = 10/brand) in resin and the repetitive application of torsional stress (300 rpm, 1.0 N·cm) by an endodontic motor with autostop when the file fractured. The number of loading cycles to fracture was recorded and analyzed by Kruskal–Wallis and Mann–Whitney U tests with Bonferroni’s correction. Bending resistance of the instruments was tested using a cantilever bending test to the 3 mm point from the tip (N = 10/brand). The stress was measured when deflection of 3 mm was subjected and statistically analyzed with a one-way analysis of variance and Tukey’s honest significance difference test (α = 0.05). V2H withstood the highest number of load applications during torsional fatigue testing (p<0.05), followed by NRT, PTN, and OS, where the differences between NRT and PTN (p=0.035) and between PTN and OS (p=0.143) were not statistically significant. V2H showed the lowest bending stiffness, followed by NRT, PTN, and OS (p<0.001). Thermal treatment of NiTi wire resulted in improved mechanical properties, and controlled memory wire provided improved flexibility and torsional fatigue resistance.

Life Estimation of SUS304 Steel Subjected to Nonproportionally Combined Push-Pull and Cyclic Torsion at 973K

2007 ◽  
Vol 345-346 ◽  
pp. 323-326 ◽  
Author(s):  
Katsuyuki Tokimasa
Keyword(s):  
Strain Range ◽  
Inelastic Strain ◽  
Fatigue Tests ◽  
Critical Plane ◽  
Plane Model ◽  
Life Estimation ◽  
Cyclic Torsion ◽  
Creep Fatigue ◽  
Thin Walled ◽  
Tubular Specimens

The present paper summarizes the fully reversed strain-controlled creep-fatigue tests conducted on thin-walled tubular specimens of SUS304 austenitic stainless steel at 973K in air under push-pull, cyclic torsion, in-phase straining and 90deg out-of-phase straining of push-pull and cyclic torsion. It is shown that, as the results of analysis of the experimental data by the strain-range partitioning methodand the critical plane model parameter, a new inelastic-strain based parameter was proposed for life estimation of SUS304 subject to nonproportionally combined push-pull and cyclic torsion by the strain-range partitioning method.

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