Accession Number : ADP009076

Title :   Experimental Investigation and Modeling of the Effect of Bore Curvature on Muzzle Motions of 60-mm Guns.

Corporate Author : ARMY ARMAMENT RESEARCH DEVELOPMENT AND ENGINEERING CENTER WATERVLIET NY BENET LABS

Personal Author(s) : Gast, Ronald G.

Report Date : SEP 1993

Pagination or Media Count : 21

Abstract : In recent years, great strides have been made regarding isolation of the dominant loads that cause beam-type vibrations in tank cannons during ballistic operation. A more subtle load type is due to the characteristic bore profile of the gun tube itself. While curvature- and inertia-induced loads due to gravity droop are known to have little effect on gun motions, a similar claim in regard to center line profile produced by other conditions (manufacturing, thermal flexure, etc.) cannot be made. Very little controlled testing has been conducted to establish the severity of this condition. This lack of data was the driving force behind the development and conduction of the test; and the simulation modelling reported herein. Tests were conducted using two 60-mm gun tubes 63 calibers long. One of the tubes possessed a great deal of in-plane curvature, while the second tube was relatively straight. In the test, the tubes were isolated from all known dominant loads by using braided cables for support and a centered breech. For both tubes, the primary plane of curvature was incrementally varied with respect to gravity, and a number of rounds were fired from each orientation. Benet Laboratories' Uniform Segments Gun Vibration model was used to conduct the simulations. The mathematical relationships regarding load functions for beam vibrations and the statistical aspects of curvature estimates were addressed and incorporated in the modelling. Both test data and modelling results confirmed that the profile of the bore and its orientation with respect to gravity has an impact upon the magnitude and characteristic of muzzle motion throughout the shot.

Descriptors :   *CURVATURE, *INTERIOR BALLISTICS, *GUN BARRELS, BORES, ESTIMATES, FUNCTIONS, GRAVITY, GUNS, INERTIA, ISOLATION, MODELS, MOTION, PROFILES, SIMULATION, TEST AND EVALUATION, VIBRATION, BORESIGHTING.

Subject Categories : Guns
      Ballistics

Distribution Statement : APPROVED FOR PUBLIC RELEASE