Fracture morphologies of carbon-black-loaded SBR (styrene-butadiene rubber) subjected to low-cycle, high-stress fatigue. [Styrene-butadiene rubber]

Conference · Mon Feb 01 00:00:00 EST 1988

OSTI ID:5369114

Goldberg, A; Lesuer, D R; Patt, J

Experimental results, together with an analytical model, related to the loss in tensile strength of styrene-butadiene rubber (SBR) loaded with carbon black (CB) that had been subjected to low-cycle, high-stress fatigue tests were presented in a prior paper. The drop in tensile strength relative to that of a virgin sample was considered to be a measure of damage induced during the fatigue test. The present paper is a continuation of this study dealing with the morphological interpretations of the fractured surfaces, whereby the cyclic-tearing behavior, resulting in the damage, is related to the test and material parameters. It was found that failure is almost always initiated in the bulk of a sample at a material flaw. The size and definition of a flaw increase with an increase in carbon-black loading. Initiation flaw sites are enveloped by fan-shaped or penny-shaped regions which develop during cycling. The size and morphology of a fatigue-tear region appears to be independent of the fatigue load or the extent of the damage (strength loss). By contrast, either an increase in cycling load or an increase in damage at constant load increases the definition of the fatigue-region morphology for all formulations of carbon-black. On the finest scale, the morphology can be described in terms of tearing of individual groups of rubber strands, collapsing to form a cell-like structure. 18 refs., 13 figs.

• Research Organization: Lawrence Livermore National Lab., CA (USA); Army Tank-Automotive Command, Warren, MI (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5369114
• Report Number(s): UCRL-97913; CONF-880480-1; ON: DE88006808
• Resource Relation: Conference: Severe environment symposium, Dallas, TX, USA, 19 Apr 1988; Other Information: Portions of this document are illegible in microfiche products
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
RUBBERS
FRACTURE PROPERTIES
BUTADIENE
CARBON BLACK
CRACK PROPAGATION
CRACKS
DEFECTS
FRACTOGRAPHY
FRACTURE MECHANICS
MATERIALS TESTING
MORPHOLOGY
POLYSTYRENE
STRESSES
SURFACES
TENSILE PROPERTIES
CARBON
DIENES
ELASTOMERS
ELEMENTS
HYDROCARBONS
MATERIALS
MECHANICAL PROPERTIES
MECHANICS
NONMETALS
ORGANIC COMPOUNDS
ORGANIC POLYMERS
PETROCHEMICALS
PETROLEUM PRODUCTS
PLASTICS
POLYENES
POLYMERS
POLYOLEFINS
POLYVINYLS
SYNTHETIC MATERIALS
TESTING
360603* - Materials- Properties