Issue 14

B. L

obato da Silva

et alii, Frattura

ed Integrità Stru

tturale, 14 (201

0) 36-44; DOI:

10.3221/IGF-ESI

S.14.04

# ( N ) A 1.30 1.08 1.04 0.97 1.00 proposed stan of notched m a universal s s of Staircase ce limit for 2 an be observ od in Silva [8 (mm) f d  .99 1. .47 1. .82 0. 1.18 3. ase method ( 1

B m 1.2 1.72 1.2 1.10 1.2 0.78 1.2 0.55 1.2 0.45 dard deviation aterials for ervo-hydraul method; the .10 6 cycles. ed from Tab ] as Lee reco (%) Uppe 1 5 5 0 fist testing sta

Specimens 8 10 12 15 20 stants used in fatigue limit 15 Hz with ine the clas erial enduran e table. It c taircase meth Class d 10 3 10 5 10 1 10 1 eters of Stairc

Table 5 : Con

correction [2

2].

Fa In stre stan the lim 5%

tigue testing order to dete ss ratio, R , dard deviati percentile b it intervals ar of fatigue lim Notch

rmine experi of -1 at a fr on number u etween step e presented it initially es radius (mm 3 5 1 5 2 8 able 6 : Exper

mentally the equency of sed to determ size and mat too in the sam timated by S ) Deviation 1.6 1.6 2.2 1.6 imental param

2.10 6 cycles, ic MTS mac quantity of In addition, . 6 that the s mmends [19 r lim. (MPa) 190.2 223.0 228.5 303.2 ge and 2 secon

all testing wa hine. The T class used, S the upper an tress increme ]. Lower lim. 154.3 173.8 212.1 202.6 d testing stage

s performed ab. 6 shows ; the step siz d lower stair nts are less t

at a the e, d ; case han

(MPa)

T

).

R E

SULTS AND

DISCUSSIO

N

En T

durance limit f hree exp the Stair

or notch radi erimental ge case testing r

us of 8 mm ometric cond esults for no

itions were t tch radius of

ested in this 8 mm. The f

study and th atigue limit f

e results are or this case is

shown in Ta 355.1 19.1 

b. 9. Fig. 2 p MPa.

lots

203 214 225 236 247 258 270 281 292 303

Stress level (MPa)

Failure Su

spension

0

1 2 3

4 5 Specimen

ch radius of 8 6 7 8 number

9 10 1 1

Figur or notch radi Staircase test nd Svensson e, the tests s atigue streng tion. In addi be verified th 6 to 10. The cy in the stan

e 2 : Plot of Sta us of 3 mm ing results fo -Lóren equ tarted from b th estimate, tion, from s at experimen refore, in thi dard deviatio

ircase testing

results for not

mm for 2.106

cycles.

En Fig Dix exp abo nor con wit wit

durance limit f . 3 plots the on-Mood a erimental tim ve average f mal distribu stant. It can h specimens h less accura

r notch radi ations, respe igger class. I the probabil econd specim tal results fo s case five sp n.

us of 3 mm. ctively, for t can be obs ity of experi en to eight r the specim ecimens wer

The average this case a erved that th mental limit h specimen ens from 1 to e sufficiently

fatigue limit re 184.2 2.  is class corre fatigue is un the experim 5 is statistic to determine

and its scatte 6 MPa. In o sponds 1.6 st der is more ental behavio ally similar to the average

r determined rder to red andard devia than 89% f r is regular results obtai fatigue limit

by uce tion or a and ned but

40