Dynamic analysis of gun barrel vibrations due to effect of an unbalanced projectile considering 2-D transverse displacements of barrel tip using a 3-D element technique (original) (raw)

Dynamic response of a 120 mm smoothbore tank barrel during horizontal and inclined firing positions

Latin American Journal of Solids and Structures, 2015

In this study, the dynamic interaction between a 120 mm smoothbore tank barrel modeled as an Euler-Bernoulli cantilever beam and an accelerating projectile during firing is presented. The interaction was modelled using a new FEM approach that took into account the projectile's inertia, Coriolis, and centripetal forces and the horizontal and inclined positions of the barrel. The mass, exit velocity and acceleration effects of the projectile on the dynamics of the barrel were investigated. The effects of the projectile's inertia, and Coriolis and centripetal forces were evaluated as well. Furthermore, the tip displacements at different firing angles were determined by transferring the mass, stiffness and damping matrices of the barrel with the addition of the instantaneous property matrices of the projectile from a local coordinate to the global Cartesian coordinate with the aid of transformation matrices. Finally, the barrel vibrations caused by the successive firings were evaluated under different firing scenarios. To demonstrate the validity of the current study, comparisons were made with the results of previous studies and a good agreement was achieved. By using the method recommended in this study, it is possible to determine the accurate dynamic behavior of any barrel with sufficient sensitivity, without any costly or time-consuming tests being necessary.

The Analysis Of The Vibratory Movement Of The Gun Barrel And Its Influence On The Firing Accuracy

International conference KNOWLEDGE-BASED ORGANIZATION, 2015

It is known that the forces and shocks that occur during the firing process of a firearm induce vibrations to the barrel of the weapon and to the weapon as a whole. There are flexural, longitudinal, radial and torsional vibrations. The most important ones are considered to be the flexural or bending vibrations, especially the ones recorded in the muzzle section. This paper presents a method of recording the flexural vibrations of the barrel in the muzzle section of a 5,56mm automatic rifle and the influence of muzzle devices, using modern equipment (high speed cameras) and dedicated software.

Some Selected Fem Analyses of Motion of a Bullet with Imperfections While Interacting with the Barrel

Journal of KONES, 2008

The intended aim of studies on the modelling of a bullet interacting with a barrel is to generate a virtual, computer-based model, experimentally verified for some selected mating conditions, and to become able to predict – with strong probability – processes and phenomena that take place within a system with imperfections. In the case under consideration the problem of contact between the barrel and the bullet has been described with the calculation method based on the penalty function. Calculations were made using the so-called direct-integration procedure, colloquially called the ,,explicit integration”. Preliminary analysis has been carried out on the effect of the shift of the centre of mass of the bullet moving in the barrel. Simulation included the bullet displacement along the barrel’s axis, with the assumed positions of the centre of mass –5% and +5% as measured from the bottom and referred to the initial model (0%). Results of numerical calculations suggest the effect of s...

A Methodology for Characterizing Gun Barrel Flexure due to Vehicle Motion

Shock and Vibration, 2001

Barrel centerline curvature is known to influence the location of projectile shot impacts. Superimposed on the unique manufactured barrel centerline is the flexed barrel shape that can occur prior to firing while the vehicle is on the move. In order to understand and quantify the effects of barrel flexure on gun accuracy, it is necessary to determine what combination of fundamental mode shapes is most likely to occur. A method to accomplish this task is described in this paper. The method is demonstrated by enumerating the 10 most likely flexed barrel shapes that were found to occur in a tank-mounted gun barrel while it traversed a bump course.

Dynamics and Stability of Gun-Barrels with Moving Bullets

In this study, the stability of a Timoshenko beam under the effect of a moving projectile will be reintroduced using simple eigenvalue analysis of a finite element model. The eigenvalues of the beam change with the mass, speed, and position of the projectile, thus, the eigenvalues are evaluated for the system with different speeds and masses at different position until the lowest eigenvalue reaches zero indicating the instability occurrence. Then the dynamics of the beam will be investigated using the Newmark algorithm at different values of speed and mass ratios. It is concluded that the technique used to predict the stability boundaries is simple, accurate, and reliable.

COOK OFF STUDY OF A 120 MM GUN BARREL USING FINITE ELEMENT METHOD

Cook off study is very important to calculate firing rate of a gun. In this paper using analytical method heat transfer to the gun barrel for given ammunition parameters was calculated. Cook off study was done analytically and subsequently finite element method was employed for cook off study using ANSYS 14.0 software .the simulation was run for 521.9 seconds and the result was found to match satisfactorily to the corresponding analytical result. Proposed scheme can accurately study cook off of a gun barrel so accurate firing rate can be determine The cook-off temperature was assumed to 180 0C for the propellant[1]. The results presented in this report are related to service condition only at 20 0C. Keywords: cook-off, gun barrel, wear, finite element method, firing rate.

Structural Integrity Analysis of a Battle Tank Gun Barrel during Service

Defence Science Journal, 2015

In the present investigation, failure assessment diagram (FAD) using R6 approach has been established for structural integrity analysis of a battle tank gun barrel. FEM based modelling was carried out to evaluate maximum stresses in the barrel section during firing. A detailed sensitivity analysis of various geometres, service and material parameters has been performed to assess their criticality on overall safety of the structures. The study has been carried out using actual material and firing data of a battle tank gun barrel and therefore it can give useful insight to a designer while selecting a material and designing a similar component.

Design and analysis of a gun barrel chamber

A gun barrel is the backbone for any type of firearm which is capable of firing any type of material with the help of stored energy either by compressing the gas and explosion of the propellants or by any other mean. During the process of firing a bullet or projectile the barrel undergoes many types of loads which produce stresses in it. So that the design of the barrel must be strong enough to withstand the heavy pressure loads. Due to the absence of the design data a simple design of the gun barrel was made using cad software. The chamber of the gun barrel was designed for the 14.5 x 114 mm bullet also known as 0.57 caliber bullet. In most of the developing countries homemade fire arm is a major problem faced by the criminologist not only because it was dangerous for the society but it is also dangerous for the holder itself. Most of the home made fire arms are made up of cheap steel and are weak in there fabrication. Keeping this thing in mind the gun barrel was to be of structural steel, to perform static analysis using ANSYS. Using a finite element analysis package a model was generated for the analysis purpose. This paper deals with the analysis of the gun barrel for the given boundary conditions. Keywords-firearm; barrel chamber; 0.57 caliber bullet; finite element analysis.