Fundamental Studies Relating to the Mechanical Behavior of Solid Propellants, Rocket Grains and Rocket Motors

Abstract

In the earlier report the information obtained from both uniaxial and biaxial tension on foam and continuum rubbers was presented. The biaxial data of foam was comparable to the uniaxial data, but it was not so for the continuum rubbers. Namely, the continuum rubbers were found dilating enormously in biaxial tension in which the thickness change was measured by the travelling microscope at the edge of specimens. Due to the above unusual result, further strip-biaxial tension tests as well as homogeneous - biaxial tension tests were performed, on the same materials SBR - 500 (1. 75 percent S), SBR - 1500 (3 percent S) and polyurethane foam with an improved technique for measurement of thickness change at the center of the specimens in order to check the dependability of earlier data. The purpose of this report is to furnish complete set of data to supplement the earlier ones from which the nature of the parameters (W_1, W_2, dJ_3/dλ, μ, etc.) can be more definitely clarified. Following it the effective Poisson's ratio can be found through which the failure criterion could be established.