FRONTINI patricia Maria
Calibration of fracture mechanics parameters and J±R curve determination in polyethylene side-grooved arc- shaped specimens
V. GARCÕÂA BROSA; C. BERNAL; P. FRONTINI
ENGINEERING FRACTURE MECHANICS
PERGAMON-ELSEVIER SCIENCE LTD
Lugar: Amsterdam; Año: 1999 p. 231 - 248
The J±R curve is determined in arc-shaped samples directly obtained from medium densitypolyethylene gas pipes by the modi®ed normalization method. The elastic and plastic factors (Zel andZpl) used in the J-integral expression are geometry sensitive and their values for side-grooved arc-shapedsamples in a three-point bending con®guration are experimentally determined. The values of the elasticcompliance and crack depth-to-width ratios are found to be related by the expression recommended inthe ASTM E813-87 standard for the standard bend specimens. The Zpl factor is determined from theexponent of the power law that best ®ts the experimental data of separation parameter versus ligamentarea and is also close to the theoretical value for three-point bending geometry. The J±R curve is alsopredicted by applying the procedure proposed in the EPRI/GE handbook and compared with theexperimental multiple-specimen results.