Issue 72

D. H. Nguyen et alii, Fracture and Structural Integrity, 72 (2025) 121-136; DOI: 10.3221/IGF-ESIS.72.09

The slab is excited by a hammer, the sampling frequency and time were 2560 Hz and 300 seconds. The slab vibration almost stops during the measurement time. The vibration data was analysed by the SSI method which set the criterion of 1% error in frequency, 5% error in damping, and 98% confidence in mode shape vectors. The stabilisation diagram is presented in Fig. 4. The characteristics of the physical model are identified by using the first four natural frequencies extracted from vibration data. The natural frequencies of mode 1, mode 2, mode 3, and mode 4 are 9.49 Hz, 41.46 Hz, 86.83 Hz, and 141.41 Hz, respectively.

Figure 3: The physical model of the UHPC slab.

Accelerometer label

Setup

S1

S2 S3 S4 S5 S6 S7 S8 S9 S10

S11

S12

S13

S14

S15

1 2 3 4 5

1

2

3

4 4 4 4 4

5

6

7

8

9

10 21 32 43 54

11 22 33 44 55

41 41 41 41 41

28 28 28 28 28

14 14 14 14 14

49 49 49 49 49

12 23 34 45

13 15 24 25 35 36 46 47

16 17 18 19 20 26 27 29 30 31 37 38 39 40 42 48 50 51 52 53 Table 3: Measurement setup.

Figure 4: The stabilization diagram.

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