Cs. Wiesner et Mr. Goldthorpe, THE EFFECT OF TEMPERATURE AND SPECIMEN GEOMETRY ON THE PARAMETERS OF THE LOCAL APPROACH TO CLEAVAGE FRACTURE, Journal de physique. IV, 6(C6), 1996, pp. 295-304
The present work investigates the temperature and specimen geometry de
pendence of the Weibull parameters of a structural steel (BS 4360 Grad
e 50D). Notched tensile, notched (Charpy-type) four point bend and fra
cture mechanics specimens have been used to study the effect of specim
en geometry. Axisymmetric and two and three-dimensional finite element
analyses have been carried out to determine Weibull parameters for th
e three specimen types at various temperatures. The results have shown
that the parameters determined using notched tensile specimens can be
regarded as temperature independent. However, the parameters determin
ed using notched bend and fracture mechanics specimens exhibited some
dependence on temperature. There were also differences between the Wei
bull parameters determined from the different specimen geometries. The
results show that there is a need to further develop the 'Local Appro
ach' to cleavage fracture to incorporate effects of temperature and pl
astic constraint. At present, it is recommended that fracture mechanic
s specimens be used for the determination of Weibull parameters if the
results are to be applied to cracked structures.