PSI - Issue 11

R. Capozucca et al. / Procedia Structural Integrity 11 (2018) 402–409

404

3

R. Capozuc

ca, E. Magagnin

i, M.V. Vecchietti

/ Structural Inte

grity Procedia 0

0 (2018) 000–000

2. D T =36. stren pres Tabl carri acce 4).

ynamic analy wo experime 80N/mm²; rei gth f y ≅ 500 ence of groov e 1 are indica ed out using a lerometer me

sis of undam ntal RC bea nforcement a N/mm² and Y e at intrados ted the main specific imp asures the acc

aged RC be ms , B1 and s four longitu oung’s mod of section 20 geometric an act hammer ( eleration of t

am B2, were b dinal bars of ulus E s =210∙k mm∙20mm; t d mechanical Brüel & Kjær he structural e

uilt with fo diameter 10m N/mm². In F he beam was parameters o , Type 8202 ) lement trigge

llowing mate m and stirru igure 1 is sh subjected to f beams. The using the com red using a h

rials: concre ps of diamete own section static and dyn experimental mon techniq ammer in a fi

te of streng r 6mm with of RC beam amic tests; i dynamic test ue where a m xed point (Fi

th f c yield with n the was obile gs.2

Fig. he dynamic e the specimen a fixed posi nel analyzer ata acquisitio eam uniform slen n and dampin element is � wn the follow

1. Geometric dim xperiment wa s, was carried tion (Fig. 4), , Multichanne n.

ensions of RC b s a Brüel & K out recordin with an aver l Data Acqui

eams. jær produced g the respons age of 10 bea sition Unit 28

T 4508 impa Tran softw

he accelerom . The dynam rted by impa sformation (F are were use Free vibratio he natural fre y inertia, she est. The inert ross-sectiona

eter used in t ic test, on all ct hammer in FT) two-chan d for the for d n of uniform b quencies of a ar deformatio ia force of the l area. As kno

Piezoelectri e of the struct ts per locatio 16 Type, and

c CCLD bran ure in 9 posit n. A Fast Fo PULSE Lab

d no ions, urier shop

2.1.

ces, the effec cement v(x,t) the beam and

T rotar inter the c

der beam are g. For a beam ∙ � ⁄ ing equation

considered b in flexure on � � where ρ i is obtained fo

elow neglecti ly the compo s density of th r free vibrati

ng gravity for nent of displa e material of on of beam:

ts of is of A is

a

b for B2 with free ams under vibrat sity s 2 /mm 4 ] Mo I [m

Fig

. 2. (a) Beam B2

hung to elastic s

prings; (b) set up

of dynamic tests

-free edge condit

ion.

etric and mecha hickness [mm] L L 160 22

nical parameters ength [mm] Young's E c [kN/

of B1 and B2 be modulus mm 2 ] Den [N 2,43

ion (undamaged c ment of inertia m 4 ] x10 7

ondition D 0 ).

Table 1. Geom Width b [mm] T t 120 � �� � � = 0 . (1) must be ��� � + �� ) in Eq.(1), an

x 10 -9

0

34.50

3.89

The � , Intro

� � �� � � + � solution of Eq � = � � s ducing Eq.(2

(1)

an harmonic d assuming

me i.e.

function of ti � = � � � � �� we

(2)

obtain: