Design and Verification Criteria for Missile Weight-Handling Equipment.
Abstract
This report describes an NSPO sponsored task to evaluate the safety and structural reliability of TRIDENT-C4 missile handling equipment. In a first phase, draft of new design specifications were examined in view of current government and industry criteria for similar service. In this second phase, design stress allowables as well as a proof loading test policy for verification of structural integrity were assessed by study and experimental programs. Structural elements of mild steel and aluminum alloy weldments and of steel wire rope are taken to typify this service. Potential sources of initial and/or use-related failure include welding defects, cold cracking, lamellar tearing, fatigue, and salt water corrosion. A structural specimen consisting of a spreader beam and wire rope pendants was designed, then tested in static and fatigue loading, with simulated proof test loadings; both air and salt water environments were imposed. Failure of the spreader beams was caused by crack propagation from a weld, with fatigue life consistent with literature data. The wire rope pendants also failed by fatigue crack propagation in the wires adjacent the core. Here the proof test overload was found to delay the fatigue damage, hence lengthen its life. A new technicque is proposed for detecting broken wires inside the rope. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1976
- Accession Number
- ADA031989
Entities
People
- E. R. Seibert
- George J. O'hara
- Hillary L. Smith
- J. M. Krafft
Organizations
- United States Naval Research Laboratory