Bolted Joints - Loading beyond Yield and its impact on mechanical properties and Fatigue Performance
(Room Sunset IV - V)
28 Feb 17
4:05 PM
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5:05 PM
The general convention is that bolted joints should always be tensioned below yield and usually with a safety factor. Additionally, the designer always ensures that the service loads also stay below yield. Some research studies have shown that on the contrary to conventional wisdom show that tensioning the studs beyond yield in the shank area improve the fatigue performance, provide resistance to loosening, added shear carrying capability via friction at the flanges among other benefits. The present paper leverages this theory and proves with laboratory testing. The results show that the bolts tensioned beyond yield do depict better mechanical properties (for extreme loading) and also show improvement (2x) in fatigue performance. Basically, meaning that once the bolts are tensioned beyong yielding, the local settling helps in improving the mechanical and fatigue properties.