Fretting Fatigue Failure in Friction Grip Bolted Joints

1968 ◽  
Vol 10 (5) ◽  
pp. 434-437 ◽  
Author(s):  
R. Spiers ◽  
M. S. G. Cullimore

Fatigue tests on a large number of double cover plate butt joints showed that the cause of failure in the majority of cases was by cracks originating in an annular area of fretting damage around the bolt hole. The nature of the fretting is discussed and the variation with load amplitude of the size of the annular area is described. Several well defined patterns of fatigue cracking were observed. These are described and their associated crack origins classified and related to the joint geometry and load levels.

2007 ◽  
Vol 353-358 ◽  
pp. 2037-2040 ◽  
Author(s):  
Shinji Hashimura

In our previous study, loosening-fatigue tests under small transverse vibrations had been performed to elucidate bolt behavior and loosening-fatigue mechanism in the long life region. In this study, the influences of bolt property class and the plastic region tightening on loosening-fatigue characteristics under transverse vibration have been investigated. Result shows that bolt property class has little influence on the loosening-fatigue limits under transverse vibration. Result also shows that the transverse loosening-fatigue limit of the bolt which has been tightened to within the plastic region is lower than the transverse loosening-fatigue limit of the bolt that has been tightened to within the elastic region. This result is the opposite of the result of the axial fatigue characteristics of bolted joints.


2021 ◽  
pp. 109963622110204
Author(s):  
Zhi-Wei Wang ◽  
Yang-Zhou Lai ◽  
Li-Jun Wang

The bending fatigue tests of single-wall and double-wall corrugated paperboards were conducted to obtain the εrms– N curves under sinusoidal and random loads in this paper. The εrms– N equation of corrugated paperboard can be described by modified Coffin–Manson model considering the effect of mean stress. Four independent fatigue parameters are obtained for single-wall and double-wall corrugated paperboards. The εrms– N curve under random load moves left and rotates clockwise compared with that under sinusoidal load. The fatigue life under random load is much less than that under sinusoidal load, and the fatigue design of corrugated box should be based on the fatigue result under random load. The stiffness degradation and energy dissipation of double-wall corrugated paperboard before approaching fatigue failure are very different from that of single-wall one. For double-wall corrugated paperboard, two turning points occur in the stiffness degradation, and fluctuation occurs in the energy dissipation. Different from metal materials, the bending fatigue failure of corrugated paperboard is a process of wrinkle forming, spreading, and folding. The results obtained have practical values for the design of vibration fatigue of corrugated box.


2021 ◽  
Author(s):  
LAUREN KADLEC ◽  
CASSANDRA HALLER ◽  
YOUNG KWON ◽  
SOO-JEONG PARK ◽  
YUN-HAE KIM

A framework was presented for a fatigue failure model of fibrous composites using a multiscale approach, which uses the fatigue data of the fiber and matrix materials, respectively. Using this model, fatigue failure of fibrous composite materials and structures can be predicted from the constituent material behaviors. To that end, fiber bundles were tested under cyclic loading to determine their residual strength and stiffness. A successful completion of the model is expected to replace many fatigue tests as the configuration of the fibrous composite is varied.


2008 ◽  
Vol 24 (03) ◽  
pp. 139-146
Author(s):  
H. Remes ◽  
P. Varsta

This paper presents the results of fatigue tests, including tests of laser hybrid and arc welded butt joints, for two plate thicknesses, 6 and 12 mm. Pure laser welded joints were also tested. The S-N curves based on nominal stresses for the different welded joints are presented. The results were further analyzed using the notch stress approach, where the fatigue notch factors were determined from the measured geometries of the welded joints. Unexpected differences in the S-N curves based on the notch stresses were found between the laser hybrid and arc welded joints and between the laser hybrid and pure laser welded joints. The reasons for this difference were studied with the help of extensive measurements of weld notch geometries. Significant differences in the geometries were observed. Taking into account the notch geometry and the notch depth, the notch stress approach partially explains the differences between the fatigue endurance limits of the laser hybrid and arc welded joints. The applicability of the notch stress approach to the fatigue design of laser hybrid welded joints is also discussed.


Author(s):  
Vamadevan Gowreesan ◽  
Kyrylo Grebinnyk

Abstract Fretting occurs when there is cyclic relative motion of extremely small amplitude between two tightly fit mating surfaces. In this process, the tight fitting load may lead to adhesion of mating surface. The subsequent relative movement breaks the adhesion and lead to local grooves and pits. The localized damage in conjunction with the stresses associated with the cyclic relative motion may lead to surface cracking. This crack subsequently may propagate by fatigue provided there is high enough cyclic stress at that location. The paper discusses a blade failure induced by such fretting related fatigue. The metallurgical evaluation of the fracture surfaces of the blades showed evidence of classical fatigue failure. However, the crack initiation location did not coincide with high stress location identified by the finite element analysis. This discrepancy along with the evidence of fretting at the crack initiation sites confirms that failures were induced by fretting. Finally, some methods to eliminate or minimize fretting damage are discussed.


2018 ◽  
Vol 165 ◽  
pp. 22004 ◽  
Author(s):  
Thomas Balutch ◽  
Bertrand Huneau ◽  
Yann Marco ◽  
Pierre Charrier ◽  
Clément Champy

For some automotive anti-vibration applications, for instance exhaust hangers, center bearing bushes or torsional vibration dampers, temperature constraints make the use of synthetic rubbers, such as EPDM, necessary because of their better heat aging resistance compared to natural rubber. The aim of this paper is to understand the features of the fatigue behaviour of an industrial EPDM compared to the wellknown natural rubber. To do so, fatigue tests are conducted on hourglass-shaped specimens, and fracture surfaces are analysed using optical microscopy and scanning electron microscopy (SEM). It appears that every samples exhibit only one root cause of failure. Thus, two types of precursors are identified as responsible of the final fracture of samples: material’s inclusions and mold flaws. Interrupted fatigue tests are then performed and fatigued samples are observed with SEM. The built procedure allows us to follow fatigue cracks initiation and propagation along cycles, and to propose local damage mechanisms for each type of precursors. A global damage scenario is finally considered and compared to the one of natural rubber described in the literature.


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