Numerical and experimental comparative study of Aluminum and hybrid mounting interfaces of launch vehicle avionics for weight reduction

Abstract

Weight is a paramount parameter for launch vehicle applications. Avionics are used for command, control and guidance of launch vehicle. Interface brackets are used for mounting of these avionic packages to the launch vehicle chassis. Dynamic loads and vibration responses dominate the design criteria for these interface brackets. The weight sensitivity on range is more prominent for the upper stages of the launch vehicle. To improve the performance of launch vehicle, employment of light weight hybrid (Aluminum honeycomb panel made up of honeycomb core with face sheets at top and bottom) bracket instead of comparatively heavy conventional all metallic aluminum alloy bracket, for a particular case of mounting two of the launch vehicle avionic packages is explored in this study. Comparable vibration responses are obtained along all three axes for the two bracket configurations (aluminium alloy vs hybrid) with packages mounted for the standard random vibration inputs. Sufficient static margin of safety is achieved for high deceleration re-entry flight loads as well. It is concluded that tremendous weight saving on mounting interfaces can be gained without compromising on factor of safety and amplification of vibration responses.