Issue 15

K. Vogel et ble values to ghness of th ed by combin

alii, Frattura ed describe the is specimen c ing experim

Integrità Struttu damage beha an be determ ent with num

rale, 15 (2011) viour of the ined numeri erical analysi

21-28; DOI: 10 bonded inter cally and exp s.

.3221/IGF-ESIS.

15.03

Th mic exp

e fracture tou ro-chevron erimental de

ghness is on specimen, the termination c

e of the suita fracture tou an be execut

face. Based o erimentally.

n a The

T H

EORY

he analy width w of 10 m e height of th well as the tructured ch

sed samples and thicknes m, Fig. 1. e specimen d structure hei ip varies for d

consist of tw s t are equal epends on t ght, Fig. 2. ifferent mat

o single chi [9, 10]. The he height of While the h erial combina

ps bonded to analysis is fo the unstructu eight of the tions.

gether. Beca cused on spe red wafer h w1 structured

use they hav cimens with and the heig chip is kept

e a quadrati both a width ht of the stru constant, th

heir ess h w2 the

c footprint, t and a thickn ctured wafer e height of

Th as uns

Figu

re 1 : Geometr

y of a micro-ch

evron-specim

en compared

to an one cent

coin.

Figure 2 : Mic

ro-chevron-sp

ecimen prepa

red from a pro

cessed wafer.

Th app par

e bonded chi roximately t ameters widt

p is loaded p o a Mode I h and thickn

erpendicular crack open ess by

to the x-y-pl ing. So the

ane in front fracture toug

of the sharp hness K IC c

notch. The li an be calcul

fting of the c ated against

rack fronts le the geomet

ads rical

MAX F Y t w  

IC K 

(1)

MIN

mum force F ed by FE-sim to estimate th an extension

Wh Y M On ana

ile the maxi IN is determin e possibility lysis. With

can be

ring a tensil nt is the com he complian

e test, the m pliance meth ce of the s

inimum of t od. It comb pecimen inc

he stress inte ines experim reases too.

nsity coeffic ent with num By keeping

ient eric the

measured du sity coefficie ck length, t

MAX

ulation. e stress inten of the cra

23