Dynamic Behavior Of Steel Weld Under Impact Loading

Since the event of911, dynamic behavior of building structure has caught theattention of researchers. So far, the mechanical properties of the steel products underboth quasistatic and impact load have been studied intensively, as well as themechanical properties of steel weld under quasistatic load. However, the dynamicmechanical properties of steel weld under accidental load such as impact andexplosion haven’t been studied too much. So, a device was designed which cantransform the impact pressure of a drop hammer tester into impact tension, and byusing the drop hammer tester of Hunan University, an experimental research of steelweld under impact load was carried. The main work was summarized as follows:(1)Based on the drop hammer tester of Hunan University, a tear tester wasdeveloped by designing a device which can transform the impact pressure into tension,thus a practical method was proposed for impact tension test.(2)Experimental research of steel plate and butt weld under static and impact loadwas carried, the time histories of strain, stress, displacement and stress-strain curve ofspecimen were obtained to analyze the effect of impact velocity(strain rate) and platethickness on the dynamic mechanical properties of steel plate and butt weld. Bycomparing the results of static and impact test, a DIF function related to strain rate ofbutt weld was fitted.(3)Experimental research of fillet weld under static and impact load was carried,the time histories of strain, stress, deformation and stress-deformation curve ofspecimen were obtained to analyze the effect of impact velocity(strain rate) and stressstate on the dynamic mechanical properties of fillet weld. By comparing the results ofstatic and impact test, a DIF function related to strain rate of fillet weld was fitted.