Citation

Buyuk M, Kurtaran H, Marzougui D, Kan CD. Int. J. Impact Eng. 2008; 35(12): 1449-1458.

Copyright

(Copyright © 2008, Elsevier Publishing)

DOI

10.1016/j.ijimpeng.2008.07.057

PMID

unavailable

Abstract

Spacecrafts and satellites in low earth orbit (LEO) are subject to HVIs by micrometeoroids and orbital debris (M/OD). M/OD impacts can damage flight or mission-critical systems, which can lead to catastrophic failure of a spacecraft or satellite. Therefore, the design of a spacecraft for an earth orbiting mission must take into account the possibility of such impacts and their effects on the spacecraft structure. The United Nations gave a priority and a separate agenda for the consideration of space debris and states that international cooperation is needed to evolve appropriate and affordable strategies to minimize the potential impact of space debris on future space missions for the sake of "Peaceful Uses of Outer Space". A spacecraft with walls thick enough to absorb the whole energy of M/OD impact would be impractical due to the weight constraints. In 1947, Whipple demonstrated the operation of a double-wall system that could be used to provide the required protection with a reasonable weight requirement. Since then, several different variations and designs of this concept have been enhanced and extensively adopted to protect the required structures and their inhabitants against such threats. In this study, stuffed type of Whipple shield (SWS) is effectively designed and optimized by using AO methodology.

In this study, predictive hydrocode simulations are coupled with approximate optimization (AO) methodology to achieve successive design automation for a projectile-Whipple shield (WS) system at hypervelocity impact (HVI) conditions. Successive design methodology is first applied to find the most dangerous threat for a given WS design by varying the shape and orientation of a projectile while imposing constraints on the total projectile mass and radar cross section (RCS). Subsequent optimization procedure is then carried on to improve the baseline WS design parameters. A parametric multi-layered stuffed WS model is considered with varying thicknesses of each layer and variable positions of the inter-layers while having a constraint on the areal density. HVI simulations are conducted by using a non-linear explicit dynamics numerical solver, LS-DYNA. Coupled finite element and smoothed particle hydrodynamics (SPH) parametric models are developed for the predictive numerical simulations. LS-OPT is employed to implement the design optimization process based on response surface methodology. It is found that the ideal spherical projectiles are not necessarily presenting the most dangerous threat compared to the ones with irregular shapes and random orientations, which have the same mass and RCS. Therefore, projectiles with different shapes and orientations should be considered while designing a WS. It is also shown that, successive AO methodology coupled with predictive hydrocode simulations can easily be utilized to enhance WS design.