Analysis of high velocity impacts of quasibrittle material fragments with a Hopkinson bar

J M Rodríguez-Sereno,J López Puente,J Pernas-Sánchez,J.A Artero-Guerrero,F Gálvez Díaz-Rubio,D.A Cendón Franco

doi:10.1051/epjconf/202125001030

J M Rodríguez-Sereno, J López Puente + Show 4 more

Open Access

https://doi.org/10.1051/epjconf/202125001030

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Abstract

In this work it has been characterized the impact behaviour of quasibrittle fragments against a Hopkinson bar in a wide range of impact velocities (70-180 m/s). Hopkinson bar is designed to measure the impact forces thanks to a proper instrumentation. In this case, semiconductor strain gauges, which sensibility is higher than common strain gauges, are used. Two material are studied to widen the range of applicability of the experimental facility: PMMA and a woven composite material. Moreover, two high speed cameras (Photron SA-Z) have been used to obtain the displacement and strain field of the fragment impactor using 3D Digital Image Correlation (DIC). A special technique has been used to print the speckle in the fragment based on previous works. The developed experimental methodology has shown the different failure modes that may happen in the fracture process when the quasibrittle fragments acts as the impactor providing a better understanding of its physical behaviour.

Highlights

The aeronautic industry is an engineering field in which aircraft designers are looking for new solutions for the structure and the engines to decrease the fuel consumption
Two material are studied to widen the range of applicability of the experimental facility: Poly Methacrylate Methil Amide (PMMA) and a woven composite material
The impact force and the strain field are analysed for similar kinetic energy impacts

Summary

Introduction

The aeronautic industry is an engineering field in which aircraft designers are looking for new solutions for the structure and the engines to decrease the fuel consumption. A potential problem that should be taken in account is the possibility of the failure of one of these blades, which may impact against the fuselage [3] These blades may be designed and manufactured with composite materials, and it will be needed to perform investigations about the behaviour of a CFRP blade impacting against an aircraft structure. In the literature it can be found many different researches about the behaviour of composite when they are subjected to impacts, but there only a few [3] that study the case of a composite fragment acting as an impactor

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