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Tactical Wheeled Vehicle Weight Reduction Initiative May, 2004 By International Projects Management (I.P.M) LLC Phone:

Preamble The attached are Examples of an on going weight reduction initiative for the HUMVEE.

PROGRAM Selected Components were analyzed to re-engineered to reduction weight by 15%-20% Brackets, Brackets Supports & Transmission Supports.

Potential Additional Components Under consideration: Alternator support bracket Chassis beams Engine components

Material and Manufacturing Method Selection Selecting the most appropriate material and manufacturing methods according to the part loading and stiffness. Special welding processes of high strength steel sheet More Accurate Casting process to reduce tolerances

Using FEA methods Using Finite Element Analysis enables us to refine the stress distribution under more realistic load application and attachment conditions, eliminating the inherent conservatism present in the original calculations. Material lightly loaded can then be safely trimmed from the original part.

Examples of FEA used for weight reduction. Part No Spring Seat: from 10.9 lbs to 9.4 lbs Part No Alternator Support: from 25.3 lbs to 21 lbs Part No Compressor Bracket: from 9.8 lbs to 8.1 lbs

Stress Report Abstract Part No Compiled Name: J. Hornstein Title: Stress Engineer Checked Name: J. Hornstein Title: Stress Engineer Approved Name: Dr Fredy H. Ornath Title: CEO Materials Systems

1 Subject: Spring Seat, Front, Stress Analysis 2Scope The scope of this report is to compare the strength of the proposed-design to the current design of the subject part under the same stipulated set of external loads. Currently the part is a low alloy, steel sheet (Ftu = 60 ksi) welding assembly while the new design is a casting made of ductile iron of higher strength (Ftu = 100 ksi). 3Abstract A coarse FEM of the current (welded) part was created and subjected to the stipulated set of applied loads. The internal loads, (reactions at the rail attachment and the part displacements and stresses) were calculated. The geometry of this model was then modified to represent the proposed design, retaining the loading and reaction system and the internal loads were calculated again. A strength comparison was then performed considering both internal loads and material properties and a safety factor for the proposed part was calculated when applicable. 4Conclusions and Recommendations The maximum calculated stresses in the current part are exceeding the UTS of the material in the attachment flanges, which is attributable to the inherent conservatism of the analysis. On the assumption that the part had passed the certification tests this should not be a matter of concern. While the strength of the proposed part is exceeding the strength of the current part, because of the material’s low elongation (3% vs. 22% for the current design) it is recommended to eliminate hot spots of tensile stresses above psi by extending the lower bosses all the way to the horizontal flanges (see Figure on the next page) 5References The contents list of the full stress report, available at materials systems ltd, is given on page

Current – image

Current welding

New casting

– Welding – FE Model plot

– Casting – FE Model plot

– Welding – FE Results plot

– Casting – FE Stress plot

Part No Stress Report: Open _Stress_Report_Abstract.doc

(R) and (L)

Stress Report Abstract Part No Compiled Name: J. Hornstein Title: Stress Engineer Checked Name: J. Hornstein Title: Stress Engineer Approved Name: Dr Fredy H. Ornath Title: CEO Materials Systems

– Original part New Part: Weight reduction accomplished by opening cutouts in original part

– Original - FEM

– Redesigned - FEM

Part No Stress Report Open _Stress_Report_Abstract.doc Note:Aluminium Cast Alloy (e.g. 300 Series Aluminium Cast Alloy, MIL-HDBK-5G chapter 3.9) could offer acceptable strength, while reducing the part weight to a third of the current 9.8 lbs

Stress Report Abstract Part No Compiled Name: J. Hornstein Title: Stress Engineer Checked Name: J. Hornstein Title: Stress Engineer Approved Name: Dr Fredy H. Ornath Title: CEO Materials Systems

– Redesigned part Weight reduction accomplished by opening cutouts in original part

– Redesigned - FEM

Part No Stress Report Open _Stress_Report_Abstract.doc Note:Aluminium Cast Alloy (e.g. 300 Series Aluminium Cast Alloy, MIL-HDBK-5G chapter 3.9) could offer acceptable strength, while reducing the part weight to a third of the current 25.3 lbs