Journal Published Online: 01 December 1982
Volume 4, Issue 4

An Equation for Bolt Clampup Relaxation in Transient Environments



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.

Author Information

Shivakumar, KN
National Research Council resident research associate, NASA Langley Research Center, Hampton, VA
Crews, JH
NASA Langley Research Center, Hampton, VA
Pages: 4
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Stock #: CTR10776J
ISSN: 0884-6804
DOI: 10.1520/CTR10776J