Issue 15

I. S. Raju et

alii, Frattura ed

Integrità Struttu

rale, 15 (2011)

35-49; DOI: 10

.3221/IGF-ESIS.1

5.05

Figu

re 7 : TTT stre

ss distribution

for peak-heat

ing condition

for Panel 10 m

odel.

Figure

8 : TTT stress

distribution f

or peak-heatin

g condition fo

r plane-strain

model.

F R

ACTURE M

ECHANICS A

NALYSES

ana ma inte bot and T

he objec the strai The fra

tive of the fr n energy rele cture mecha face defects e TTT stress rate defects Typical inter fects are disc

acture mech ase rates, and nics analyses were introd . Three type (those comp face and sub ussed.

anics analyse determine if were perfo uced at the s of defects w letely within strate defects

s is to evalua defects can rmed using maximum s ere conside the substrat are presente

te the defect become unst the plane-str tress locatio red: interface e), and comb d schematica

driving force able for each ain model. n (see Fig. defects (tho ined interfac lly in Fig. 9.

s, which are of the loadin For the fra 8) and perp se along the e-substrate d In this pap

characterized g conditions cture mecha endicular to coating-subst efects (thos er, only inter

by

. nics the rate e in face

lyses, subsur ximum tensil rface), subst h regions). substrate de

(a

) Interface def

ect.

(b

) Substrate de

fect.

Fig

ure 9 : Typical

interface and

substrate defe

cts.

41