Summary of Calculations Performed to Evaluate the Structural Integrity of the 6-Pack Container Pallet

Technical Report · Fri Oct 01 00:00:00 EDT 1999

DOI:https://doi.org/10.2172/792646· OSTI ID:792646

Hrousis, C A

The 6-Pack Container Pallet is a space-frame structure, designed by Mason & Hanger Corp. to hold six AL-R8 containers together in a convenient bundle. The AL-R8 containers hold nuclear weapon components that require special care and consideration. The primary purpose of the 6-pack assembly is storage, but there is some manipulation as the 6-pack is loaded, moved and stacked. Recently, there has been an upgrade to a new AL-R8-SI container that is heavier than its predecessor was. The analysis discussed herein was conducted to ensure that the increased stresses due to the heavier containers are within design safety limits. At this time, however, there is disagreement as to what the strength requirements for the 6-pack pallet are. Depending on which classification applies to the structure, a factor of safety (yield stress over design stress) of 3.0 or more may need to be satisfied. This report documents strength analyses of loaded 6-packs performed at Lawrence Livermore National Laboratory (LLNL). The entire 6-pack assembly was discretized into a mesh with a total of 38682 first-order finite elements. The stresses were found for four characteristic load cases using the implicit code NIKE3D. This was a static strength analysis only. Dynamic loading was not considered. Stability, also, was not addressed. There are two 6-pack pallet designs under consideration: one that uses 1/2 inch diameter bolts and one with 3/8 inch bolts. In both cases, the maximum torque applied to the bolts is 55 in-lbf. This analysis finds the minimum factor of safety based on yield to be less than 3.0 in the main load path of both the 1/2 inch and 3/8 inch diameter bolt designs. In general, the peak stresses found in the 1/2 inch bolt design are less than those of the 3/8 inch bolt design. At the welded ends of the main tube section that spans the length of the pallet, the minimum safety factor is 2.14 when 1/2 inch bolts are used and 1.77 when 3/8 inch bolts are used. Minimum safety factors of 1.91 and 1.78 were found around the bolt holes in the lateral supports in the 1/2 inch bolt and 3/8 inch bolt designs, respectively.

• Research Organization: Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
• Sponsoring Organization: USDOE Office of Defense Programs (DP) (US)
• DOE Contract Number: W-7405-Eng-48
• OSTI ID: 792646
• Report Number(s): UCRL-ID-138070; TRN: US200304%%549
• Resource Relation: Other Information: PBD: 1 Oct 1999
• Country of Publication: United States
• Language: English

Related Subjects

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE
42 ENGINEERING
CLASSIFICATION
CONTAINERS
DESIGN
FASTENERS
LAWRENCE LIVERMORE NATIONAL LABORATORY
NUCLEAR WEAPONS
SAFETY
STABILITY
STORAGE
STRESSES
TORQUE