Finite Element Analysis in product development:
With the advancement in technology, PMP is looking to new, innovative ways to use technology in the development of ammunition.
One of the recent additions to the tools available to Product Development and Production Engineering is the purchase of the Finite Element Package, called Abaqus, developed by Dassault Systems. One of the benefits of this software is that it enables PMP to design, develop and test products and tooling in a virtual 3D environment, before any actual manufacturing takes place.
What is Finite Element Analysis?
Finite Element Analysis is a mathematical modelling technique used for analysing engineering problems in structural, heat transfer and fluid flow. In its simplest form, it involves breaking down complex shapes and structures into smaller elements in order to simplify the calculations required to solve the required engineering problem. In doing this, it is possible to obtain stress distributions and deformation throughout the structure. This technique can be applied to static loading or dynamic loading situations.
Uses for Finite Element Analysis:
Currently within PMP, Finite Element Analysis is being used by the Production Engineering department to help with the development of tooling in metal forming operations like the 35mm Link, and to help solve production problems involving metal forming operations like cartridge case manufacturing.
Finite Element Analysis is also being used by the Product Development department to help with the development of medium calibre fuzes, and also to help solve dispersion problems that occurred in the development of the new range of 30mm x 173mm ammunition for the Hoefyster project.
The benefit for PMP in using this Finite Element software is that many different designs and configurations can be tested in the virtual 3D environment, before any tooling or components need to be manufactured, and before extensive live testing and evaluation need to be conducted.
Finite Element Analysis of the Crimping Operation in Medium Calibre Ammunition (projectile in cartridge case):
One of the recent analysis that was done by Production Engineering and Product Development was on the steel jaw crimping operation on the 30mm x 173mm project. The objective of the exercise was to try and optimise both the tooling design and product design in order to obtain consistent bullet extraction force.
The force required to push the projectile out of the cartridge case during firing has a direct influence on the internal ballistics (what happens inside the barrel) and also has an influence on the external ballistics (what happens outside the barrel). During the development of the 30mm x 173mm range of ammunition, one of the major concerns was the extremely tight dispersion specification as well as the internal ballistics of the locally developed propellant.
A finite element model was developed to simulate the crimping operation, which included the projectile, cartridge case and crimping tool. With the help of the Abaqus software, it was possible to make improvements to the crimping process and the design of the cannelure.
What now remains is to make improvements to the bullet pull machine and conduct tests to validate the finite element model so that it can be used in the future for other medium calibre products.
