scholarly journals Low-cyclic Fatigue Test of Adhesive Bond Reinforced with Biodegradable Fabrics

2016 ◽  
Vol 16 (5) ◽  
pp. 1205-1211 ◽  
Author(s):  
Jan Zavrtálek ◽  
Miroslav Müller
2019 ◽  
Vol 13 (1) ◽  
pp. 57-60
Author(s):  
Damla Özsu Kırıcı ◽  
Ertuğrul Karataş ◽  
Ahmet Demirhan Uygun ◽  
Ezgi Doğanay Yıldız ◽  
Kezban Meltem Çolak ◽  
...  

Background. The aim of the present study was to compare the cyclic fatigue resistance of novel nickel titanium rotary pathfinding instruments. Methods. Twenty instruments were selected for each file system. A simulated stainless steel root canal, with a 90° angle of curvature and a curvature radius of 3 mm, was used for cyclic fatigue test of the ProGlider (#16, progressive taper: 0.02‒ 0.085), PathGlider (#15, taper: .03), and One G (#14, taper: .03) instruments. Statistical analyses were performed with oneway ANOVA (P=0.05). Post hoc Tukey tests were used to determine any statistically significant differences between the groups. Results. The ProGlider instruments exhibited significantly more cyclic fatigue resistance than both PathGlider and One G instruments (P<0.001). One G instruments had significantly more resistance to fracture than PathGlider instruments (P<0.05). Conclusion. ProGlider instruments had better cyclic fatigue resistance than PathGlider and One G instruments.


2014 ◽  
Vol 8 (3) ◽  
pp. JAMDSM0039-JAMDSM0039 ◽  
Author(s):  
Qingrong FAN ◽  
Kiyotaka IKEJO ◽  
Kazuteru NAGAMURA ◽  
Masato KAWADA ◽  
Mitsuo HASHIMOTO

2018 ◽  
Vol 165 ◽  
pp. 05003 ◽  
Author(s):  
Audun Johanson ◽  
Luigi Mario Viespoli ◽  
Bård Nyhus ◽  
Antonio Alvaro ◽  
Filippo Berto

The work here presented focuses on the test methodology related to effect of stress concentrators in strain controlled structures. Cable sheathing as used in subsea power cables are investigated by cyclic fatigue testing, Digital Image Correlation (DIC) and 3D Finite Element Analysis. Focus is put on the strain distribution in conventional specimen geometries and under the presence of artificial notches. It is evident that standardized fatigue testing provides limited input to the final fatigue life of strain controlled power cable sheathing both accounting for expected and unintended stress concentrators. The limitations can be explained by measured strain distribution inherent in most fatigue test specimens. The use of DIC and 3D FEM provides valuable insight into both the theoretical and practical stress and strain distribution. This can help in understanding and overcoming geometrical test constraints, when compared to the actual component loading mode.


2017 ◽  
Vol 74 (1) ◽  
pp. 23
Author(s):  
Victor Talarico Leal Vieira ◽  
Hélio Pereira Lopes ◽  
Carlos Nelson Elias ◽  
Leticia Chaves de Souza ◽  
Emmanuel João Nogueira Leal da Silva ◽  
...  

Objective: Hyflex CM instruments were developed for debridement of the root canal system. The control-memory alloy recovers its shape on sterilization, thereby allowing instrument reuse. This study investigated the effect of shape recovery by sterilization on the fatigue life and crack formation of Hyflex CM NiTi instruments. Material and Methods: the cyclic fatigue test was performed in two groups: In the first, it was continuously performed to establish the fatigue life (group 1, n = 10); in the second, it was performed with outages of 30s to evaluate cracks’ nucleation and propagation (group 2, n = 10). The test was performed using a stainless steel canal that was 1.5mm in diameter and 3.5mm in depth, with an arc of 9.42mm and radius of curvature of 6mm. The instruments were driven at 300 rpm. The fatigue time was recorded using a digital stopwatch (Technos). An electronic microscope (Quanta 250) was used to observe the crack formation and growth during the cyclic fatigue. Results: the autoclaved instruments endured 1196.67+214.63 cycles, and the non-autoclaved endured 1000+199.42 cycles until the occurrence of fracture. The t-student test (?=5%) revealed a significant difference. The cyclic fatigue test with pauses demonstrated a significantly longer cyclic fatigue life than the continuous cyclic fatigue test (p<0.05). Conclusion: as revealed by SEM images, cracks grow with an increase in the number of cycles to fracture (NCF). It can be concluded that the shape of Hyflex CM instruments recovered by autoclaving withstood significantly more NCF than non-autoclaved instruments (p<0.05), demonstrating an improvement of approximately 16%.


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