the ipm group farmington hills, michigan. contact us beni dror 27003 hills tech drive farmington...
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The
IPM
GROUP
Farmington Hills, Michigan
Contact usBeni Dror
27003 Hills Tech Drive
Farmington Hills, MI 48331
Tel: 248 489 9490,
Fax: 248 479 0771
e-mail: [email protected]
Web:www.ipmworld.com
Mail Address: P.O.Box 252223
West Bloofield, MI 48325
Tactical Wheeled Vehicle Weight Reduction Initiative
May, 2004By
International Projects Management (I.P.M) LLC
Phone: 248 489 94 90
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. 12338191- Spring Seat:from 10.9 lbs to 9.4 lbs
Part No. 12469497- Alternator Support:
from 25.3 lbs to 21 lbs Part No. 12469498- Compressor Bracket:
from 9.8 lbs to 8.1 lbs
Stress Report AbstractPart No. 12338191
Compiled
Name: J. HornsteinTitle: Stress Engineer
Checked
Name: J. HornsteinTitle: Stress Engineer
Approved
Name: Dr Fredy H. OrnathTitle: CEO Materials
Systems
1 Subject: Spring Seat, Front, Stress Analysis
2 Scope
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).
3 Abstract
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.
4 Conclusions 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 100000 psi by extending the lower bosses all the way to the horizontal flanges (see Figure 2.1.1 on the next page)
5 References
The contents list of the full stress report, available at materials systems ltd, is given on page 2.1.4.
Current 12338191 – image
Current 12338191 - welding
New 12338191 - casting
12338191 – Welding – FE Model plot
12338191 – Casting – FE Model plot
12338191 – Welding – FE Results plot
12338191 – Casting – FE Stress plot
Part No. 12338191
Stress Report:
Open 12338191_Stress_Report_Abstract.doc
12469497(R) and 12469498(L)
Stress Report AbstractPart No. 12469498
Compiled
Name: J. HornsteinTitle: Stress Engineer
Checked
Name: J. HornsteinTitle: Stress Engineer
Approved
Name: Dr Fredy H. OrnathTitle: CEO Materials
Systems
12469498 – Original part
New Part: Weight reduction accomplished by opening cutouts in original part
12469498 – Original - FEM
12469498 – Redesigned - FEM
Part No. 12469498
Stress ReportOpen
12469498_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 AbstractPart No. 12469497
Compiled
Name: J. HornsteinTitle: Stress Engineer
Checked
Name: J. HornsteinTitle: Stress Engineer
Approved
Name: Dr Fredy H. OrnathTitle: CEO Materials
Systems
12469497 – Redesigned part
Weight reduction accomplished by opening cutouts in original
part
12469497 – Redesigned - FEM
Part No. 12469497
Stress ReportOpen
12469497_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