Analysis of local delaminations caused by angle ply matrix cracks

Technical Report · Mon Nov 01 04:00:00 EST 1993

OSTI ID:5225878

Salpekar, S A; Obrien, T K; Shivakumar, K N

Two different families of graphite/epoxy laminates with similar layups but different stacking sequences, (0,theta,-theta) sub s and (-theta/theta/0) sub s were analyzed using three-dimensional finite element analysis for theta = 15 and 30 degrees. Delaminations were modeled in the -theta/theta interface, bounded by a matrix crack and the stress free edge. The total strain energy release rate, G, along the delamination front was computed using three different techniques: the virtual crack closure technique (VCCT), the equivalent domain Integral (EDI) technique, and a global energy balance technique. The opening fracture mode component of the strain energy release rate, Gl, along the delamination front was also computed for various delamination lengths using VCCT. The effect of residual thermal and moisture stresses on G was evaluated.

• Research Organization: National Aeronautics and Space Administration, Hampton, VA (United States). Langley Research Center
• OSTI ID: 5225878
• Report Number(s): N-94-24083; NASA-TM--109052; NAS--1.15:109052; CNN: RTOP 538-02-10-01
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
CALCULATION METHODS
CARBON
CRACK PROPAGATION
ELEMENTAL MINERALS
ELEMENTS
EPOXIDES
FAILURES
FINITE ELEMENT METHOD
GRAPHITE
MATERIALS
MATRIX MATERIALS
MINERALS
MOISTURE
NONMETALS
NUMERICAL SOLUTION
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
SIMULATION
STRESSES
THERMAL STRESSES