Micromechanics analysis of space-simulated thermal deformations and stresses in continuous fiber-reinforced composites

Miscellaneous · Sun Jan 01 00:00:00 EST 1989

OSTI ID:6071010

Bowles, D E

Space simulated thermally induced deformations and stresses in continuous fiber reinforced composites were investigated with a micromechanics analysis. The investigation focused on two primary areas. First, available explicit expressions for predicting the effective coefficients of thermal expansion (CTE's) for a composite were compared with each other, and with a finite element (FE) analysis, developed specifically for this study. Analytical comparisons were made for a wide range of fiber/matrix systems, and predicted values were compared with experimental data. The second area of investigation focused on the determination of thermally induced stress fields in the individual constituents. Stresses predicted from the FE analysis were compared to those predicted from a closed-from solution to the composite (CC) model, for two carbon fiber/epoxy composites. A global-local formulation, combining laminated plate theory and FE analysis, was used to determine the stresses in multidirectional laminates. Thermally induced damage initiation predictions were also made. The type of analysis (i.e., CC or FE) was shown to significantly affect the distributions and magnitudes of the predicted stresses. Thermally induced matrix stresses increased in absolute value with increasing fiber volume fraction, but were not a strong function of fiber properties. Multidirectional (O2/plus or minus theta)sub(s) laminates had larger predicted thermally induced matrix stresses than unidirectional laminates, and these stresses increased with increasing lamination angle theta. Thermally induced matrix failure predictions, using maximum stress failure criterion based on the normal interfacial stress component and the measured transverse lamina strength, were in excellent agreement with experimental data.

• Research Organization: Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (USA)
• OSTI ID: 6071010
• Resource Relation: Other Information: Ph.D. Thesis
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COMPOSITE MATERIALS
STRESS ANALYSIS
THERMAL EXPANSION
CARBON FIBERS
CRACK PROPAGATION
EPOXIDES
FAILURE MODE ANALYSIS
FINITE ELEMENT METHOD
REINFORCED MATERIALS
TEMPERATURE EFFECTS
THERMAL STRESSES
EXPANSION
FIBERS
MATERIALS
NUMERICAL SOLUTION
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
STRESSES
SYSTEM FAILURE ANALYSIS
SYSTEMS ANALYSIS
360603* - Materials- Properties