Optimal Design of Strap-Down Inertial Navigation Support under Random Loads

摘要

In order to realize miniaturization and light weight of the strap-down inertial navigation system, and then to make sure that it works well under random loads, optimal design is applied to the strap-down inertial navigation support with the methods of topology optimization and size optimization. Firstly, based on the installation requirement of devices and connection requirement of the support and the carrier, the initial structure of the support is designed. Topology optimization with FEA software ANSYS is adopted on the initial structure to get the basic one. Then 5 critical sizes are chosen as design variables, and the support structure is optimized by means of size optimization to reach light weight with satisfying the requirement of dynamic stiffness. Finally, random vibration analysis is applied to the initial structure. In the mean time, random vibration test is carried out to qualify the analysis method. After the qualification, a random vibration analysis is applied to the optimized support structure to get the rms of displacement response and acceleration response of the support to validate whether the optimized structure is appropriate. The results indicate that the dynamic stiffness of the optimized support structure satisfies the design requirements, and its weight is lighter 49.38% than that of the initial one. This research can be a reference to the structure design of supports under random loads, and the result has been applied to the development and manufacture of a prototype aerocraft.