Analysis of Bending a Square Ceramic Plate under Strong Rotation
Final rept. Feb-Jul 1998
ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
Pagination or Media Count:
The U.S. Army has a continuing interest in smart weapons systems. Among them are projectiles employing independent logic. Smart weapons use printed circuitry with chips supplying the smarts for the systems autonomic functions. Experience has shown that considerable thought is required to design circuits that remain effective when subjected to severe environmental conditions. Launch conditions can place a projectiles components under axial loads as high as 40,000 gs, with spin rates up to 270 rs and balloting loads up to 2,000 gs. Although short in duration, these loads can break even the most robust design. Unfortunately, when failure occurs, it is not obvious that a loading mechanism caused the problem, hence, making it difficult to make design corrections. This report gives a simplified technique to determine if spin loading can break an internally housed chip. In particular, radial loading on the sense-and-destroy armor missile SADARM projectiles 68000 chip is examined. The methods employed here offer a quick means to eliminate potential problems, without employing sophisticated finite element techniques. Thin-plate theory is assumed adequate for determining stress levels in this chip, which is located off the rotation axis. Approximations for the chips loading and boundary conditions are considered. Computational results are presented and examined.
- Guided Munitions