Accession Number:

ADA052051

Title:

Stress Wave Propagation in Bars Due to Normal Impact on Water.

Descriptive Note:

Final rept.,

Corporate Author:

NAVAL SURFACE WEAPONS CENTER WHITE OAK LAB SILVER SPRING MD

Personal Author(s):

Report Date:

1977-08-01

Pagination or Media Count:

401.0

Abstract:

The stress wave response of solid, right circular cylindrical bars due to normal impact on an undisturbed water surface was investigated analytically and experimentally. The analytical problem was formulated as a two dimensional axisymmetrical elastic bar impacting on an initially perfectly flat, compressible water half space. Method of characteristics - finite difference solutions were obtained for the Lagrangian system of bar equations and Eulerian water equations, and programmed for computer solution. Strain-gaged magnesium bars were shot with a 3 inch diameter air gun into a chamber which was evacuated to the vapor pressure of water for preserving an undisturbed water surface prior to impact. Shots were made with a bare magnesium nose unmitigated and with rigid polyurethane foam noses of densities 5 and 15 pounds per cubic feet. The use of a foam nose greatly reduces the transmitted stress to the bar.

Subject Categories:

  • Armor
  • Mechanics
  • Radiofrequency Wave Propagation

Distribution Statement:

APPROVED FOR PUBLIC RELEASE