ISSN: 0884-6804
CODEN: JCTRER
Page Count: 4

An Equation for Bolt Clampup Relaxation in Transient Environments
Crews, JH
Senior engineer, NASA Langley Research Center, VA

Shivakumar, KN
National Research Council resident research associate, NASA Langley Research Center, VA

Abstract

The viscoelasticity of resin-based laminates allows the clampup force on bolts to relax, with a corresponding degradation in joint strength. We have studied clampup relaxation for steady temperature and moisture (T-M) conditions [1], but in typical applications laminate temperature and moisture both vary with time. These transient conditions influence clampup in two ways: first, the laminate thermal expansion (contraction) and moisture swelling (shrinkage) cause elastic changes in the clampup, and second, the T-M conditions influence the rate of clampup relaxation.

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Paper ID: CTR10776J
DOI: 10.1520/CTR10776J
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