Project 1

Experimental impact cratering with the novel EMI two-stage light gas gun: ground-breaking crater dimensions and improved material models

Project directors:

Klaus Thoma, Frank Schäfer
Fraunhofer Institute for High-Speed Dynamics, Ernst-Mach-Institut (EMI)

Research staff:

Tobias Hoerth (PhD student, EMI)

Summary

This project comprises the performance of impact experiments on natural rock targets and the characterization of the dynamic material behavior of rock materials under extreme loads. The project is central to the entire MEMIN program.

The impact experiments will be used to investigate the influence of velocity and mass of the impactor and porosity and structure of the target on the crater formation process, and the ejection of rock materials from the targets. Key aspects of the research are the quantification of the influence of the shock duration and pressure amplitude on the shock metamorphic overprint of minerals and rocks, as well as the investigation of impact induced waveform phenomena (propagation, damping, reflexion, spallation). The planned experiments are performed on gun accelerators unique in Europe.

The material characterization serves to investigate the mechanical behavior of the relevant natural rocks over a wide strain rate regime. To this purpose, experimental methods will be applied that are suitable to systematically submit the materials to loads ranging from quasi-static conditions (strain rates of ca. 10 1 s-1) to extreme dynamic (strain rates of ca. 106 s-1) loads. This material characterization provides the necessary parameters for predictive material models including an Equation-of-State and a strength and failure model.

Results

You can find the results here.