Sponsor:

U.S. Army Defense Ammunition Center

Research Team:

Cengiz Altan, Brad S. Williams, L. Aktas, John M. Byers

Universities Involved:

University of Oklahoma

Start Date:

01/01/05

End Date:

12/31/05

Summary:

* Detailed design of a modular pallet system used for ammunition transport
* Achieve flexible design to accommodate multiple loading configurations
* Development of a finite element model for structural analysis
* Structural analysis of the assembled modular pallet
* Analysis of stress distribution and deformation induced under various loading
The purpose of this phase was to determine the capabilities and feasibility of the modular pallet system developed by the University of Oklahoma for the Container Roll-In/Out Platform (CROP). This phase was to include detailed dimensioning, FEA mesh creation, material investigation, and structural analyses of the modular pallet system under various loading conditions. In addition to the original scope of the project, two scaled-down rapid prototype pallet modules were built to help visualize the assembly/disassembly and operation of the pallet.

Detailed design and structural analysis for the Modular Pallet System proposed by the University of Oklahoma within the scope of the previous CELDi project, OU03-DAC2 will be performed. Researchers at the School of Aerospace and Mechanical Engineering at the University of Oklahoma have proposed a conceptual design for a Modular Pallet System for packaging and shipment of ammunition on container roll-in/out platform (CROP). The proposed concept replaces the currently used wood pallets, restraints, and straps. It is also reusable and geometrically flexible to accommodate ammunitions of various sizes.

In order to proceed towards building a prototype of the proposed system, detailed geometric design, dimensioning, and structural analysis will be performed. Initially, detailed dimensioning of each one of the pallet components will be provided. The dimensions that can be used as variables in the design analysis will be identified. Based on these, total cargo volume of each pallet as well as the full pallet assembly on CROP will be determined. In addition, total weight of individual parts and the assembled system will be assessed for the selected candidate materials.

A detailed finite element model of each pallet component and the assembled modular pallet will be developed. The required computational effort and the necessary mesh size for structural analysis will be assessed. Structural analysis of an assembled pallet will be performed by the finite element model developed. The loading conditions will be provided by Defense Ammunition Center. The stress and deformation behavior of the pallet module will be obtained. Maximum deformation and stresses within each pallet component will be investigated.

The initial design was shown to require some changes due to the location of some stress concentrations, large weight, and displacements.
Each material had its strengths and weaknesses and only one material out of the four attempted did not meet the minimum loading requirements of 2500 lb. The best performer, in terms of load capacity/unit weight was Vectra B230 with a load to weight ratio of over 50. The largest load bearing material was aluminum at 18,000 lb, but it only had a load to weight ratio of just over 33. While Vectra A sustained a load of 4,600 lb, its weight was very close to that of Vectra B230. From these results, it appears that Vectra B230, the carbon fiber reinforced polymeric composite presents the best alternative.