Feasibility Assessment of Conceptual 105-mm M68 Composite Tubes
Abstract
A study is reported in which the thermal, stress, fabrication, durability, and weapon interface problems associated with implementation of composite materials in a 105-mm M68 tube configuration are evaluated. It is shown that thermal factors associated with the lowered heat capacity and thermal conductivity of composite materials compared to that of steel are best minimized by judicious placement of composite material along the tube. The dominant thermal effect associated with replacement of steel by composite material is determined to result from the composite's low heat capacity per unit volume (roughly 60% that of steel). Increase of composite thermal conductivity would do little toward reduction of required composite working temperature in desired high rate firing schedules. A composite tube design which achieves at least a 10% reduction in M68 tube weight is suggested. Based on use of polyimide- graphite composite material, the design is shown to withstand a 65-round continuous burst of M456 ammunition at 8 rounds/min. The composite tube designs were evaluated for temperature and stress profiles through application of a finite element computer code developed specifically in this work. The code accounts for pressure, thermal, cure, and autofrettage stresses prior to, during, and after firing. The computer listing is given in the report.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1986
- Accession Number
- ADA177729
Entities
People
- C. C. Morphy
- F. A. Vassallo
Organizations
- Calspan