Nonpenetrating Damage Identification Using Hybrid Lamb Wave Modes from Hilbert-Huang Spectrum in Thin-Walled Structures

<table class="figure-group"><tr class="fig-image" id="a"><td><object data="https://static.hindawi.com/articles/sv/volume-2017/5164594/figures/5164594.fig.0014a.svgz" name="5164594.fig.0014a" type="image/svg+xml"></object></td></tr><tr class="fig-caption"><td><b>(a) </b><svg height="12.0575pt" id="M88" style="vertical-align:-3.2911pt" version="1.1" viewbox="-0.0498162 -8.7664 11.2312 12.0575" width="11.2312pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M409 504C401 567 396 607 392 642C354 654 312 665 266 665C137 665 60 583 60 487C60 374 161 325 225 290C300 250 355 215 355 141C355 68 311 21 235 21C131 21 86 122 71 183L41 176C48 128 61 42 68 21C78 16 93 8 118 0C142 -7 175 -15 216 -15C349 -15 438 69 438 174C438 287 344 333 265 374C186 414 138 449 138 522C138 576 172 631 249 631C336 631 363 562 380 499L409 504Z" id="g121-81"></path></g><g transform="matrix(.0091,0,0,-0.0091,6.162,3.132)"><path d="M245 635C92 635 37 457 37 312C37 149 91 -12 244 -12C395 -12 449 166 449 312C449 469 395 635 245 635ZM243 598C332 598 358 454 358 312C358 173 334 26 245 26C158 26 128 174 128 313S152 598 243 598Z" id="g50-49"></path></g></svg> wave only</td></tr><tr class="fig-image" id="b"><td><object data="https://static.hindawi.com/articles/sv/volume-2017/5164594/figures/5164594.fig.0014b.svgz" name="5164594.fig.0014b" type="image/svg+xml"></object></td></tr><tr class="fig-caption"><td><b>(b) </b><svg height="12.0575pt" id="M89" style="vertical-align:-3.2911pt" version="1.1" viewbox="-0.0498162 -8.7664 14.0628 12.0575" width="14.0628pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M673 0V28C608 34 594 43 563 129C499 303 432 494 370 665L339 656L132 132C98 43 84 37 20 28V0H238V28C162 35 154 45 175 108C188 150 203 192 219 237H432C454 176 474 122 487 83S491 36 428 28V0H673ZM418 280H234C265 362 296 450 328 535H330L418 280Z" id="g121-63"></path></g><g transform="matrix(.0091,0,0,-0.0091,8.983,3.132)"><path d="M245 635C92 635 37 457 37 312C37 149 91 -12 244 -12C395 -12 449 166 449 312C449 469 395 635 245 635ZM243 598C332 598 358 454 358 312C358 173 334 26 245 26C158 26 128 174 128 313S152 598 243 598Z" id="g50-49"></path></g></svg> wave only</td></tr><tr class="fig-image" id="c"><td><object data="https://static.hindawi.com/articles/sv/volume-2017/5164594/figures/5164594.fig.0014c.svgz" name="5164594.fig.0014c" type="image/svg+xml"></object></td></tr><tr class="fig-caption"><td><b>(c) </b>Hybrid Lamb wave modes</td></tr></table>

<div>Comparison of damage maps (experiment).</div>

Shock and Vibration

fig14

Figure 14

Figure 14: Nonpenetrating Damage Identification Using Hybrid Lamb Wave Modes from Hilbert-Huang Spectrum in Thin-Walled Structures 