scholarly journals Competitive Failure of Bolt Loosening and Fatigue under Different Preloads

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Guangwu Yang ◽  
Long Yang ◽  
Jingsong Chen ◽  
Shoune Xiao ◽  
Shilin Jiang

AbstractExisting research on the competitive failure relationship, failure mechanism, and influencing factors of bolt loosening and fatigue under different preloads is insufficient. This study analyzes the competitive failure relationship between bolt loosening and fatigue under composite excitation through competitive failure tests of bolt loosening and fatigue under different preloads. The results indicated that the failure mode of the bolt is only related to the load ratio (R) and is unrelated to the initial preload and excitation amplitude, which only determine the failure life of the bolt. The small axial loads of composite excitation can restrain bolt failure, and the significant degree of this restraining effect is different for different preloads. Subsequently, a fracture analysis of the bolt was performed to verify the competitive failure relationship of the bolt from a microscopic perspective, and the competitive failure mechanism of the bolt was determined. Based on the findings, we propose a calculation equation for the optimal preload of 8.8 grade high-strength bolts that can serve as a reference for engineering applications.

2009 ◽  
Vol 417-418 ◽  
pp. 845-848 ◽  
Author(s):  
Chang Wang Yan ◽  
Jin Qing Jia ◽  
Ju Zhang

In order to investigate the seismic damage and performance of steel reinforced ultra high strength concrete composite joint subjected to reversal cycle load, six interior strong-column-weak-beam joint specimens were tested with various axial load ratio and volumetric stirrup ratio. A discussion on the crack mode and ductility was presented. It was found that all joint specimens failed in bending with a beam plastic hinge in a ductile manner, with crack propagation different from the weak-column-strong-beam joint. The experimental results indicated that test parameters of the steel reinforced ultra high strength concrete composite joint with good seismic performance may be referred for engineering application.


Author(s):  
Long Yang ◽  
Bing Yang ◽  
Guangwu Yang ◽  
Yang Xu ◽  
Shoune Xiao ◽  
...  
Keyword(s):  

2012 ◽  
Vol 174-177 ◽  
pp. 455-459 ◽  
Author(s):  
Xiao Wei Li ◽  
Xue Wei Li ◽  
Xin Yuan

For expedite the development of high titanium heavy slag concrete, eight high titanium heavy slag high strength reinforced concrete (HTHS-HSRC) scale model column are studied. The eight HTHS-HSRC model columns are tested under reversed horizontal force. Primary experimental parameters include axial load ratio varying from 0.3 to 0.5, volumetric ratios of transverse reinforcement ranging from 1.38% to 1.56%, strength of high titanium heavy slag high strength concrete varying from 55.9 to 61.6 N/mm2 and configurations of transverse reinforcement. It is found from the test result that HTHS-HSRC model columns provides comparable seismic performance to those usually used reinforced concrete column in terms of member ductility, hysteretic and energy dissipation capacity. Primary Factors of Displacement Ductility of Model Columns are also discussed.


2011 ◽  
Vol 341-342 ◽  
pp. 432-435
Author(s):  
Wei Huang ◽  
Ya Feng Li ◽  
Kai Wen Tian ◽  
Fu Jun Shang ◽  
Yong Liu ◽  
...  

The failure mechanism of tungsten matrix composite was studied with microscale numerical simulation. The results show that high strength tungsten particles are the real loading elements of composite, its strength level embodies the whole property of the composite to some extent. The real stress in tungsten particles is much higher than the external load, so failure may take place when the external load is less than the theoretical strength of tungsten particles.


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