Modeling fatigue crack growth in cross ply titanium matrix composites

Conference · Sat May 01 04:00:00 EDT 1993

OSTI ID:6219350

Bakuckas, Jr, J G; Johnson, W S

In this study, the fatigue crack growth behavior of fiber bridging matrix cracks in cross-ply SCS-6/Ti-15-3 and SCS-6/Timetal-21S laminates containing center holes was investigated. Experimental observations revealed that matrix cracking was far more extensive and wide spread in the SCS-6/Ti-15-3 laminates compared to that in the SCS-6/Timetal-21S laminates. In addition, the fatigue life of the SCS-6/Ti-15-3 laminates was significantly longer than that of the SCS-6/Timetal-21S laminates. The matrix cracking observed in both material systems was analyzed using a fiber bridging (FB) model which was formulated using the boundary correction factors and weight functions for center hole specimen configurations. A frictional shear stress is assumed in the FB model and was used as a curve fitting parameter to model matrix crack growth data. The higher frictional shear stresses calculated in the SCS-6/Timetal-21S laminates resulted in lower stress intensity factors in the matrix and higher axial stresses in the fibers compared to those in the SCS-6/Ti-15-3 laminates at the same applied stress levels.

• Research Organization: National Aeronautics and Space Administration, Hampton, VA (United States). Langley Research Center
• OSTI ID: 6219350
• Report Number(s): N-93-27062; NASA-TM--108988; NAS--1.15:108988; CONF-930532--; CNN: RTOP 763-23-45-85
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
ALLOYS
CRACK PROPAGATION
CRACKS
FATIGUE
FIBERS
MATERIALS
MATRIX MATERIALS
MECHANICAL PROPERTIES
REINFORCED MATERIALS
SHEAR
STRESS INTENSITY FACTORS
STRESSES
TITANIUM ALLOYS