Volume 29, Issue 4 (July 2001)
The Calibration Functions of the Arc-Shaped Bend Specimen
The geometry functions of the Common Format Equation developed by Donoso and Landes were evaluated for the arc-shaped bend specimen. A(B), with a span-to-width ratio S/W of 4 and r1/r2 = 0.95. The specimen geometry functions, Gel = C*BW(b/W)μ, and Gpl = CBW(b/W)m, in the elastic and the plastic range, respectively, were numerically computed with the aid of a two-dimensional, nonlinear, plane strain finite element analysis. The elastic solution, in the form of an elastic compliance, was compared to values obtained in the concise format from the K-solutions of ASTM E 1290. The plastic solution, on the other hand, was compared with available experimental values. The numerical results showed μ = ηe1 = 2,1185 and m = ηpl = 2,0894 for the A(B) specimen analyzed. As is the case with other bend-type specimen geometry, μ ≈ m, which indicates that the J-integral may be computed as one single integral form, in terms of total displacement. For this, it is proposed to use as eta values (clastic and plastic) for the A(B) specimen, the same values of μ derived from the K-solution, dependent on the size ratio r1/r2.