Research Article
Center Impedance Method for Damping Measurement
Table 3
Frequencies (in Hz) of thick bars at room temp.
| | Bar | Mode no. | Experimentally Observed frequencies | Frequencies based on Young’s modulus from Center Impedance | Error for Center Impedance | Frequencies based on Young’s modulus from Oberst | Error for Oberst |
| | R690-64 S.no 4 | 1 | 110 | 115.4 | 5% | 311.8 | 183% | | R690-64 S.no 4 | 3 | 614.5 | 616.6 | 0.4% | 1690 | 175% | | R690-64 S.no 5 | 1 | 115 | 111.3 | 3% | 311.3 | 179% | | R690-64 S.no 5 | 3 | 633.5 | 615.3 | 3% | 1687 | 166% | | R690-64 S.no 6 | 1 | 115 | 113.5 | 1% | 308 | 167% | | R690-64 S.no 6 | 3 | 633.5 | 627.3 | 1% | 1675 | 164% | | 3wk R690-64 40 Deg | 1 | 129 | 128 | 0.8% | 303.9 | 135% | | 3wk R690-64 40 Deg | 3 | 680 | 708 | 4% | 1649.7 | 142% | | 4wk R690-64 40 Deg | 1 | 120.2 | 109.8 | 9% | 303.9 | 153% | | 4wk R690-64 40 Deg | 3 | 663.2 | 608 | 8% | 1649.7 | 149% |
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