| The nature and effects of residual stresses on the cracking
behaviour of indentation cracks in ZTA/Zr02 laminates are
studied. The laminates develop alternating residual stresses
in the different layers, i.e. compression in one layer (ZT A)
and tension in the other (Zr02). However, these biaxial
residual stresses behave like the uniaxial ones when observed
on the cross-sectional surface using an indentation
technique. This paper discusses the influence of residual
stresses on the indentation crack-patterns in a ZT A/Zr02
multilayer composite. As expected, compressive stresses
tend to suppress crack-initiation and propagation. Strongly
bonded interface with the proper control of residual stresses
can offer an effective approach for arresting the advance of
crack-tip and imparting crack-deflection, without seriously
affect the strength of the laminates. An equation for determination
of these stresses was established and was wellsupported
by experimental data. |
