Delamination fracture and acoustic emission in carbon, aramid and glass-epoxy composites

Conference · Sun Feb 01 00:00:00 EST 1987

OSTI ID:6633022

Dharan, C K.H.

Results of an investigation into the opening mode (Mode I) delamination fracture behavior of carbon, aramid and glass-epoxy composites are described. The effect of loading rate and reinforcement geometry (unidirectional vs woven) on fracture toughness was determined, and observation of the fracture surface was used to derive possible microfailure modes. The results show that the crack energy release rate for a woven composite was greater than that of unidirectionally reinforced composites. Acoustic emission was employed to detect crack initiation in an attempt to obtain correlation with the delamination fracture toughness. The earliest signal appeared to correlate well with the delamination fracture toughness, indicating that the processes involved in fracture initiation determines the magnitude of the steady state fracture toughness. Results show that the three materials tested behave in different ways (i.e., have different failure modes) during delamination, suggesting that a single theory cannot be expected to explain delamination in all composite materials.

• Research Organization: Lawrence Berkeley Lab., CA (USA)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 6633022
• Report Number(s): LBL-22984; CONF-870745-1; ON: DE87008224
• Resource Relation: Conference: 6. international conference on composite materials, London, UK, 20 Jul 1987; Other Information: Portions of this document are illegible in microfiche products
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COMPOSITE MATERIALS
FAILURE MODE ANALYSIS
FRACTURE PROPERTIES
ACOUSTIC EMISSION TESTING
ARAMIDS
CARBON
CRACK PROPAGATION
EPOXIDES
ACOUSTIC TESTING
ELEMENTS
MATERIALS
MATERIALS TESTING
MECHANICAL PROPERTIES
NONDESTRUCTIVE TESTING
NONMETALS
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
PETROCHEMICALS
PETROLEUM PRODUCTS
PLASTICS
SYNTHETIC MATERIALS
SYSTEM FAILURE ANALYSIS
SYSTEMS ANALYSIS
TESTING
360603* - Materials- Properties