Experimental study of the behaviour of building structural elements under soft impact

Dynamic three-point bend tests are performed on sm all beams specimen made of a quasi-brittle material. The most classical hypotheses needed to a nalyse the tests with SHPB, which are based on a st ate of quasi-static balance of the body, cannot be used . In order to get the behaviour it is necessary to perform a transient analysis of the specimen response. In m ost cases, the useful duration of the test the el aps d time between the beginning of the load and the tota l failure is lower than the time needed by the wa ves to reach the supports. The test is thus called a “o ne point bending test". In the case of bending fail ure, an analysis of the tests is possible by using only the measures given by the input bar. The technique is based on the knowledge of the analytical solution of the ransient elastic response of the specimen. The fai lure mechanisms involved are specific features of the dy namic response. Different failure modes can be observed according to the loading rate: bending or shear fracture, single or multiple fractures. The determination of the bending moments and the rotati ons of the beam section, where the failure occurs, lead to an estimation of the strength and the failu re energy.