Process-induced viscoelastic stress in composite laminates
In recent years, considerable interest has developed in evaluating the stress response of composite laminates which is associated with cooling the material system from the cure temperature to room temperature. This research examines the fundamental nature of time-dependent residual-thermal stresses in composite laminates which are caused by the extreme temperature reduction encountered during the fabrication process. Viscoelastic stress in finite-width, symmetric composite laminates is examined on the basis of a formulation that employs an incremental hereditary integral approach in conjunction with a quasi-three dimensional finite element analysis. A consistent methodology is developed and employed for the characterization of lamina material properties. Special attention is given to the time-dependent stress response at ply-interface locations near the free-edge. In addition, the influence of cooling path on stress history is examined. Recently published material property data for graphite-epoxy lamina is employed in the analysis. Results of the investigation generally indicate that nominal differences between the thermoelastic and viscoelastic solutions are obtained. Slight changes of the final stress state are observed to result when different cooling paths are selected for the temperature history. The methodology employed is demonstrated to result in an accurate, efficient, and consistent approach for the viscoelastic analysis of advanced composite laminates.
- Research Organization:
- Illinois Univ., Urbana (USA)
- OSTI ID:
- 6460224
- Country of Publication:
- United States
- Language:
- English
Similar Records
Effects of moisture upon the optimal temperature path of the viscoelastic symmetric composite laminates after post cure
Large deformation of hygrothermoviscoelasticity for environmental effects on the cross-ply laminates
Related Subjects
360301 -- Composite Materials-- Preparation & Fabrication-- (-1987)
360303* -- Composite Materials-- Mechanical Properties-- (-1987)
COMPOSITE MATERIALS
COOLING
ELASTICITY
FINITE ELEMENT METHOD
INTERFACES
MATERIALS
MECHANICAL PROPERTIES
NUMERICAL SOLUTION
RESIDUAL STRESSES
STRESSES
TENSILE PROPERTIES
THERMAL STRESSES
TIME DEPENDENCE