Jb. Lee et Jh. Song, A STUDY ON THE BEHAVIOR OF A CRACK LOCATED AT THE STRIPING ZONE IN A THERMALLY STRATIFIED PIPE, Nuclear Engineering and Design, 143(2-3), 1993, pp. 229-237
The behavior of a small crack located at the thermal striping zone in
a thermally stratified piping is numerically investigated. The effects
of the parameters such as fluctuation frequency/amplitude of the dens
ity interface, heat transfer coefficient near the thermal striping zon
e, and crack depth on the behavior of the crack are examined to identi
fy the governing parameters. The effect of the contact surfaces on the
stress intensity factor range is also examined for several levels of
the internal fluid pressure. The stress intensity factor range, DELTAK
(I), is used to describe the crack behavior due to the thermal stripin
g. The findings of the numerical investigation are as follows: (1) the
value of DELTAK(I) increases up to a specific Fourier number and then
decreases beyond the specific Fourier number. (2) With the increasing
Biot number the value of DELTAK(I) increases and the Fourier number(F
o) at which the DELTAK(I) vs. Fo curve has a peak decreases. This mean
s that the behavior of a crack located at the thermal striping zone ha
s a large dependence on the oscillating frequency of the density inter
face and the heat transfer coefficients. (3) The value of DELTAK(I) in
creases up to a specific crack depth and then decreases beyond the spe
cific crack depth. (4) If the fluid pressure is lower than a specific
value, the value of DELTAK(I) decreases because of the crack surface c
ontact.