Study On Fatigue Behavior Of Hollo-bolt And Hollo-bolted Connection

Blind fastener or blind bolt is one of fastening system,and the system improved on standard bolts with special processing technolgy is applied for installations that one side of the connection can be accessed merely.Blind fasteners offer many advantages,including i)high tensile and shear strength,ii)potential use in tension applications and moment resisting connection,iii)uniform high clamping force,and iv)vibration resistance.Furthermore,blind bolts can easily be installed by unskilled technicians using portable equipment.The strength performance of this system connected with joints has been investigated previously.However,the performance of such system under fatigue loading is still unknown.The researches on the fatigue behavior of the M16 G10.9 blind bolt Hollo-Bolt in this thesis are outlined as follows:(1)Experimental researches on Hollo-Bolt and standard bolt had been implemented under static loading.Mechanical properties were discussed contrastively.Ulteriorly axial fatigue test under constant load amplitude and axial variable load amplitude on Hollo-Bolt had been carried out.Therefore,statistical analysis procedure proposed by Eurocode 3 for the statistical analysis was valid for fatigue test data.Statistical analysis was conducted to establish S-N curves and to predict the fatigue life of the proposed Hollo-Bolt.Simultaneously effect of loading sequence under variable load amplitude on the fatigue behavior of blind bolts was discussed.Miner Accumulated Fatigue Damage Rule was adopted to estimate the fatigue life of Hollo-Bolt,which provided the reference for the fatigue design method on Hollo-Bolt.(2)Experimental researches on Hollo-Bolted T-stub connections under monotonic loading were studied.The force-displacement curves of T-stub connections were measured.The seismic performance of Hollo-Bolted T-stub connections was experimentally studied by applying cyclic loading in the top angle subsequently.Based on the experimental results,the salient response such as bearing capacity,flexural stiffness,ductility and dissipated energy of the T-stub connections are examined with emphasis on the ffects of the relative thickness between angle and column wall,width of angle leg et al,which will provide the data source for the nonlinear finite element analysis and the establishment of design method.