Single-stage gas gun

• Subject Area: Materials Engineering
• Term: Funded in 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 537373841

This proposal is for a single-stage compressed gas gun to carry out high-velocity impact (HVI) tests on lightweight structures made of metallic or fibre-reinforced materials in order to understand and simulate damage mechanisms and to be able to evaluate new structural concepts with regard to their damage resistance or energy absorption capability. Such HVI load cases play a major role in aircraft construction and other technical disciplines because they often represent the dimensioning load cases for a large number of structural components for safety reasons. Examples include bird strike, hailstorm, impact from tyre or rim fragments, etc. In the research of new, more sustainable or lighter aircraft designs, the experimental and numerical consideration of HVI loads is of paramount importance. Such a gas gun is based on the principle of the abrupt expansion of a compressed gas from a pressure vessel, which accelerates a projectile embedded in a sabot along a long tube to shoot it at a fixed sample or structural component. The impact of the projectile on the test structure and the structural response are evaluated qualitatively and quantitatively on the one hand by means of high-speed cameras as well as optical 3D strain field measurement via Aramis sensor, and on the other hand by means of strain gauges, force sensors or acceleration sensors, for which a high-speed data recorder with a sufficiently high number of measuring channels is required. In the field of aeronautical research, larger projectiles are particularly relevant, i.e. bird subsitute projectiles made of gelatine, tyre parts, wheel rim parts, drone components, etc. Therefore, we are applying for a gas gun with a sufficiently large tube diameter (220 mm) for projectile masses in the range of 900-3,600 g at impact velocities of about 100-250 m/s. The goals of the research associated with this large-scale research facility as part of Prof. Heimbs' new appointment at TU Braunschweig include the investigation of the highly dynamic material and damage behaviour of lightweight structural materials incl. the development of more resistant materials, the research of impact protection systems (for the safety of structures, tanks, passengers), the research of novel impact load cases such as drone collision, the research of simplified, standardised substitute projectiles, the improvement and validation of numerical simulation methods, the experimental demonstration of the impact resistance of large-scale demonstrators or prototypes desired in many research projects, the development of industry-specific guidelines, standards and requirements, as well as the utilisation and transfer of HVI research findings from aeronautics research to the fields of automotive engineering, rail transport or wind turbines.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Druckluftbeschleuniger (Gaskanone)
• Instrumentation Group: 2920 Schlagprüfmaschinen, Vibrations- und Beschleunigungs-Prüfanlagen
• Applicant Institution: Technische Universität Braunschweig
• Leader: Professor Dr.-Ing. Sebastian Heimbs