TY - JOUR
T1 - JII fracture testing of a plastically deforming material
AU - Banks-Sills, Leslie
AU - Sherman, Dov
PY - 1991/7
Y1 - 1991/7
N2 - A compact model II fracture specimen was previously analyzed and employed to determine the mode II fracture toughness KII c, of perspex. In employing this specimen for a more ductile material such as aluminium, it was observed that the load vs. crack sliding displacement record becomes nonlinear for small loads. Thus, concepts of linear elastic fracture mechanics cannot be employed. To this end, the specimen was calibrated for J-integral testing, so that JII c mesurements can be performed. In this study, mode I and II tests are carried out on an aircraft aluminium alloy, AI 7075-T7351. First, standard KI c tests are performed leading to a value of 27.9 15-1 which would be equivalent to a JI c of 10.7 kN/m. Then standard JI c tests are carried out on this material with specimen thicknesses, of 5, 7.5 and 9.9 mm, leading to an average JI c value of 10.5 kN/m. Methods for JII testing are proposed; a series of specimens of six thicknesses between 5 and 16 mm are employed for testing. An average JII c value was found to be 40.2 kN/m which yields a KII c value of 54.1 15-2. Thus, KII c is seen to be approximately twice that of KI c for this material.
AB - A compact model II fracture specimen was previously analyzed and employed to determine the mode II fracture toughness KII c, of perspex. In employing this specimen for a more ductile material such as aluminium, it was observed that the load vs. crack sliding displacement record becomes nonlinear for small loads. Thus, concepts of linear elastic fracture mechanics cannot be employed. To this end, the specimen was calibrated for J-integral testing, so that JII c mesurements can be performed. In this study, mode I and II tests are carried out on an aircraft aluminium alloy, AI 7075-T7351. First, standard KI c tests are performed leading to a value of 27.9 15-1 which would be equivalent to a JI c of 10.7 kN/m. Then standard JI c tests are carried out on this material with specimen thicknesses, of 5, 7.5 and 9.9 mm, leading to an average JI c value of 10.5 kN/m. Methods for JII testing are proposed; a series of specimens of six thicknesses between 5 and 16 mm are employed for testing. An average JII c value was found to be 40.2 kN/m which yields a KII c value of 54.1 15-2. Thus, KII c is seen to be approximately twice that of KI c for this material.
UR - http://www.scopus.com/inward/record.url?scp=0026185822&partnerID=8YFLogxK
U2 - 10.1007/BF00035166
DO - 10.1007/BF00035166
M3 - ???researchoutput.researchoutputtypes.contributiontojournal.article???
AN - SCOPUS:0026185822
SN - 0376-9429
VL - 50
SP - 15
EP - 26
JO - International Journal of Fracture
JF - International Journal of Fracture
IS - 1
ER -