Accession Number:

ADA090626

Title:

Two-Dimensional Transient Hygrothermal Stresses in Bodies with Circular Cavities: Moisture and Temperature Coupling Effects.

Descriptive Note:

Final rept.,

Corporate Author:

LEHIGH UNIV BETHLEHEM PA INST OF FRACTURE AND SOLID MECHANICS

Personal Author(s):

• Sih,G. C.
• Ogawa,Akinori

Report Date:

1980-08-01

Pagination or Media Count:

75.0

Abstract:

When moisture andor temperature are suddenly changed on the boundary of a solid, stresses and strains are introduced and they can be further aggravated by the presence of stress raisers such as voids or cavities. A time dependent finite element procedure is developed for solving the hygrothermal stresses around a circular cavity in a finite plate. Numerical results are displayed graphically for the T3005208 graphite fiber-reinforced epoxy resin material. The size of the hole relative to the plate is varied for three different cases such that the interaction of moisture and temperature is investigated in conjunction with changes in the solid geometry. Possible failure sites are also examined by application of the strain energy density criterion. These locations are determined from the stationary values of the strain energy factor. The hygrothermal influence tends to move the failure site away from the cavity while the mechanical load gives the opposite effect. The proportion of the energy stored by hygrothermal and mechanical disturbances is investigated. Author

Descriptors:

• *STRESS ANALYSIS
• *MOISTURE
• *THERMAL STRESSES
• STRESS STRAIN RELATIONS
• DEGRADATION
• TIME DEPENDENCE
• MATRICES(MATHEMATICS)
• FINITE ELEMENT ANALYSIS
• FIBER REINFORCED COMPOSITES
• CAVITIES
• VOIDS
• NUMERICAL METHODS AND PROCEDURES
• GRAPHITED MATERIALS
• EPOXY RESINS

Subject Categories:

• Laminates and Composite Materials
• Mechanics
• Thermodynamics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE