A Viscoelastic/Damage Simulation Model for Filament-Wound Pressure Vessels.
Abstract
A model to predict the viscoelastic/damage response of a filament-wound composite cylindrical pressure vessel to a proof-test loading is developed. The matrix material of the composite system is assumed to be isotropic and linearly viscoelastic. A damage model is proposed which produces a quadratic relationship between the transverse modulus and the circumferential strains. A nonlinear model results and is solved by iterative solution based on the damage response. The elastic-viscoelastic correspondence principle is used to produce, in the Laplace domain, an associated elastic solution for the circumferential strains. The associated elastic solution is inverted by using the method of collocation to yield the time-dependent circumferential strain. A numerical example to demonstrate the simulation model is included. A proof-test loading of 5.5 MPa is applied for one minute. Results indicate that the damage as modeled reduces the instantaneous failure load from 9.977 MPa to 7.771 MPa, or 22%. The creep that occurs during the constant load phase of the proof-test loading induces a 3.65% increase in the damage. After removal of the proof-test loading, the strain recovers to zero. However, the transverse modulus does not recover. This emphasizes the need to consider the effects of proof-test loading when the in-service load limits are determined. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1985
- Accession Number
- ADA166389
Entities
People
- Johnny L. Prater
Organizations
- United States Army Aviation and Missile Command