Experimental study on impact fracture of cantilever beam-column specimen with prefabricated crack

Abstract

The impact fracture mechanics of the cantilever beam-column specimens with different inclination angles(0°,30°,60°) prefabricated cracks subjected to hammer impact loading were studied by using digital dynamic caustic test system.The results show that the specimen with prefabricated crack of 0° reaches the fracture toughness first and starts to crack.Along with inclination angle increases,the energy accumulated at the crack tip becomes difficult,result in the initiation time is longer;The angle of crack has a great influence on the crack propagation trajectory,the bigger the angle is,the bigger the crack curving is.The increase of crack inclination leads to the vibration amplitude of the crack propagate rate increase and the average crack propagation rate increase,which indicates the influence of slanting crack on the velocity is larger than that of straight crack;With the inclination angle of prefabricated crack increases,the dynamic fracture toughness KICd gradually decreases, KIICd gradually increases and the composite characteristic becomes more obvious.The results provide a guidance for the prediction of crack propagating trajectory and the dynamic response of structure with cracks.

Keywords

• beam-column specimen
• impact
• caustic
• dynamic fracture
• prefabricated crack
• stress intensity factor