Table 1: Experimental and numerical values of natural frequencies for various crack depth ratios (uncorrected numerical values shown within brackets and corrected numerical results are shown with the asterisk). V: vertical and H: horizontal.

Frequency Crack depth ratios 0.0% 10% 20% 30% V H V H V H V H First 34.134 (34.338) 34.338* 43.633 (43.858) 43.858* 34.125 (34.337) 34.262* 43.515 (43.855) 43.550* 33.816 (34.337) 34.286* 43.363 (43.849) 43.046* 33.778 (34.336) 34.176* 43.343 (43.844) 42.570* Second 76.703 (78.269) 78.269* 78.792 (80.436) 80.436* 76.657 (78.265) 77.889* 78.806 (80.425) 79.481* 76.483 (78.266) 77.953* 78.424 (80.408) 78.054* 76.195 (78.260) 76.835* 78.382 (80.392) 77.398* Third 191.652 (190.42) 190.42* 199.499 (196.13) 196.13* 191.491 (190.42) 189.99* 199.204 (196.12) 195.04* 191.256 (190.42) 190.05* 199.069 (196.10) 193.47* 190.859 (190.41) 189.42* 199.006 (196.08) 192.17* Fourth 367.563 (366.26) 366.26* 383.139 (382.40) 382.40* 367.282 (366.26) 365.94* 379.423 (382.39) 380.85* 365.883 (366.26) 366.03* 379.213 (382.36) 378.62* 365.752 (366.26) 365.55* 379.109 (382.33) 376.84* Frequency Crack depth ratios 40% 50% 60% 70% V H V H V H V H First 33.556 (34.334) 33.964* 43.185 (43.841) 42.964* 33.145 (34.329) 33.563* 42.947 (43.841) 42.300* 32.774 (34.320) 32.762* 42.862 (43.841) 42.274* 31.286 (34.300) 30.964* 42.069 (43.837) 41.962* Second 75.572 (78.248) 76.240* 78.298 (80.384) 76.412* 74.553 (78.228) 74.743* 78.214 (80.382) 76.151* 73.401 (78.186) 71.921* 77.644 (80.381) 76.059* 69.774 (78.088) 67.206* 75.896 (80.370) 75.361* Third 190.076 (190.40) 188.34* 198.671 (196.07) 191.55* 188.763 (190.38) 186.58* 198.299 (196.07) 191.46* 187.240 (190.33) 183.81* 197.993 (196.06) 191.37* 182.790 (190.22) 179.66* 194.457 (196.05) 190.66* Fourth 363.809 (366.25) 364.68* 378.435 (382.32) 376.03* 359.989 (366.23) 363.21* 377.565 (382.32) 375.98* 355.839 (366.19) 360.84* 376.664 (382.32) 375.92 343.971 (366.10) 357.25* 373.689 (382.30) 375.03*