A Computer Program and Approximate Solution Formulation for Gun Motions Analysis
Abstract
The purpose of this paper is to describe some of the features associated with a finite element computer program for approximate solutions of a gun dynamics problem. The lateral motion of a gun tube is modeled by an Euler- Bernoulli beam. The difficulties of the problem are due to various complicated loading and support conditions which can be nonconservative, highly discontinuous and time dependent. The solution formulation for this generally non-self-adjoint problem has been presented in an earlier paper. In terms of finite element discretization, the two-dimensional shape function of spatial and time coordinates is chosen as a product of two one-dimensional shape functions; each for its respective coordinate and both being Hermitian polynomials. The generalized coordinate are then the displacement, slope, velocity and time derivatives of the slope at each node point. The correspondence between local and global generalized coordinates is described. The 'stiffness matrices' of spatial and time-effect, contributed by the recoil force, pressure and curvature induced force and the moving mass of a projectiles are derived. It is interesting to observe that the strong discontinuities associated with these forces disappear as a result of the smoothing effect of integration in spatial as well as in time coordinates. The present approach to deal with the moving support problem efficiently is also pointed out in this paper. Numerical results of a demonstrative problem are presented.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1979
- Accession Number
- ADA074935
Entities
People
- J. J. Wu
Organizations
- United States Army Armament Research, Development and Engineering Center