Escuela de Politécnica Superior

This article discusses the influence of the dimensions of the damping rings used for interrupting a dynamic tension experiment on the results of a modified split Hopkinson tension bar. The damping rings enclosed in an external fixture which modifies the classical split Hopkinson tension bar play a significant role in buffering the dynamic tension experiments before the specimen reaches its failure strength. Finite element simulations of high-strain-rate tension experiments are accomplished on Aluminium 7017-T73 alloy specimens when varying the thickness or the cross-sectional area of the damping rings. Finite element analyses described herein are applied to simulate the effects of the variation of the damping rings’ dimensions to provide a reference for improvement of a modified split Hopkinson tension bar experimental apparatus and guidance for future studies in which optimum dimensions for the damping rings can be studied. In view of this research, it can be concluded that the thickness of the damping rings is a factor that can resolutely influence the interrupted dynamic tension experiment results, while their cross-sectional area can be excluded as a factor influencing the results of the modified split Hopkinson tension bar experiments.

This article discusses the influence of the thickness of the damping rings used for interrupting a dynamic tension experiments on the results of a modified split Hopkinson tension bar (SHTB). In this paper a device enclosed in an external fixture used for interrupting a dynamic tension experiment in a SHTB is studied. The novelty of this manuscript with respect to previous studies lies in the fact that the dynamic tension experiment in a SHTB is interrupted in order to study the mechanical behavior of the material at high strain rates. The role played by such device is to interrupt the experiment at different levels of plastic deformation, particularly when the specimen is about to reach its failure strength. Finite-element (FE) simulations of high-strain-rate tension experiments are accomplished on a particle-reinforced metal matrix composite specimen (namely SiCreinforced ZC71 magnesium alloy) when varying the thickness of the damping rings. Interrupting the test before the specimen breaks offers the possibility of being able to study in a more detailed way the deformation process of such material at high strain rates. Therefore, this work focuses on the study of the behaviour of materials undergoing high strain rates, developing a tool which allows materials to withstand different levels of strain rates in a controlled manner and providing guidance for future studies. In view of this research, it can be concluded that the thickness of the damping rings is a factor that can resolutely influence the interrupted dynamic tension experiment results avoiding the specimen’s failure by optimally buffering the experiment using 0.8mm thick lead damping rings.