Abstract :
[en] Due to the increase in terroristic attack and catastrophic events, the engineering structures are more and more likely to be subjected to abnormal loading conditions. Moreover, exceptional and unpredictable fatalities (extreme wind actions, explosions, car impacts...etc.) could lead to dreadful consequences, such as the partial or total progressive collapse of the structures. In view of this, it is required for engineers and researchers to have a better knowledge of all the phenomena associated to such exceptional loadings on structures. The behaviour of structures under impact, which is the main topic of the present paper, is a complex phenomenon and the response of a structure depends on a large number of variables such as the sensitivity of the materials to high rates of deformation, imperfection of the system, type and velocity of the impacting body among others. The present paper presents the behaviour of simply supported beams under impact loads. In particular, nine drop-weight impact tests have been performed at different level of impact energy. Within the proposed paper, the experimental impact tests conducted on simply support beams will be first presented. Then, exploiting the power of FEM analyses performed using the commercial software Abaqus/CAE© and validated against experimental evidences, different modelling techniques, along with several material models, are examined and compared. From these results, the ability of a detailed FE modelling to predict the response of impacted beams, when a proper modelling of the material behaviour at high rate of deformation is ensured, is discussed and a first estimation of the dynamic increase factor (DIF) for beam under impact loadings is given.
