Optimum design of mounting components of a mass property measurement system

• Design of a inertia property measurement system.
• Modelling and FE simulation of torsion rod and flexure for inertia measurement.
• Optimum design of torsion rod and flexure based on stiffness ratio.
• Development of the system and measurement of inertia properties.
• Verification of the design methodology using FE simulation with experiments.

Measurement of inertia properties of aerospace vehicle and submarine are vital to meet the intended motion objectives. The Moment of Inertia (MOI) is calculated by measuring the frequency of free torsional oscillation of the object mounted on a nearly friction less air bearing. For getting accurate measurement and to nullify the effect of undesired vibrations, the stiffness of the different components of the mounting and fixture (torsion rod, flexure) should be maintained appropriately. The optimum design of torsion rod and flexure is based on ensuring desired natural frequencies in different modes. Initiating with an analytical approach, the actual dimensions of the components are determined based on natural frequencies obtained by finite element analysis of the components. Simulated results are verified with experimental results.