Table 3 Prestressing force and corresponding measured 1\(\mathrm{st}\) and 2\(\mathrm{nd}\) frequencies by Zhang and Li (2007).
From: On the Evaluation of Prestress Loss in PRC Beams by Means of Dynamic Techniques
Prestressing force | 1\(\mathrm{st}\) frequency | 2\(\mathrm{nd}\) frequency |
|---|---|---|
(kN) | (Hz) | (Hz) |
0 | 28.36 | 100.71 |
20 | 28.36 | 102.67 |
40 | 28.83 | 103.09 |
60 | 29.32 | 104.07 |
80 | 29.48 | 105.05 |
100 | 29.69 | 105.50 |
120 | 29.80 | 105.53 |