Abstract :
The effect of variable fibre radius on the initial creep rate, ˙ε∗, of monofilament ceramic
fibres was investigated using a numerical integration method. The following parameters
were studied: (i) radius variation geometry, (ii) creep stress exponent, n, (iii) fractional
radius variation, rν , and (iv) fraction,m, of the characteristic radius variation wavelength, λ;
the ranges of n (0 < n < 3) and rν (0 < rν < 0.5) were chosen to be similar to those for
current ceramic fibres based on the silicon carbide (SiC) system. Values of ˙ε∗ were found to
be consistently greater compared to those for a constant radius fibre with an equivalent
mean radius and increased with both n and rν . The main result of this work was a
recommendation for creep testing of monofilament ceramic fibres to be limited to certain
radius variation geometries and gauge lengths.
C 2005 Springer Science + Business Media, Inc.
