Bk. Neale, ON THE BEST FIT CURVE THROUGH CRACK-GROWTH FRACTURE-RESISTANCE DATA, Fatigue & fracture of engineering materials & structures, 16(4), 1993, pp. 465-472
The ESIS recommendations for determining the fracture resistance of du
ctile materials make use of an offset power law to evaluate the best f
it curve to crack growth fracture resistance data, Evaluation of the o
ffset power law requires the use of non-linear regression analysis, al
though an iterative linear regression analysis can be used if the data
are transformed by taking logarithms. The two analyses are compared w
ith a proposed alternative formulation for the offset power law which
can be evaluated using an iterative linear regression analysis without
the need to transform the data. Confidence limits are evaluated for t
he J-DELTAa data of two steels and are shown to depend on the analysis
procedures.