Experimental Study on Lateral Resolution of Phased Array Ultrasonic Testing of Irregular Structure Weld Defects

<table class="table-group" id="tab8"><tr><td><table class="table"><tr><td class="thead-hr" colspan="7"><hr/></td></tr><tr class="thead"><td class="align_left" rowspan="2">Independent variable</td><td class="align_center" rowspan="2">Symbol</td><td class="align_center" colspan="5">Coding</td></tr><tr class="thead"><td class="align_center">−1.68</td><td class="align_center">−1</td><td class="align_center">0</td><td class="align_center">1</td><td class="align_center">1.68</td></tr><tr><td class="thead-hr" colspan="7"><hr/></td></tr><tr><td class="align_left">Center frequency</td><td class="align_center"><i>X</i><sub>1</sub> (MHz)</td><td class="align_center">5</td><td class="align_center">7</td><td class="align_center">10</td><td class="align_center">13</td><td class="align_center">15</td></tr><tr><td class="align_left">Focal length</td><td class="align_center"><i>X</i><sub>2</sub> (mm)</td><td class="align_center">10</td><td class="align_center">18</td><td class="align_center">30</td><td class="align_center">42</td><td class="align_center">50</td></tr><tr><td class="align_left">Number of elements</td><td class="align_center"><i>X</i><sub>3</sub></td><td class="align_center">8</td><td class="align_center">19</td><td class="align_center">36</td><td class="align_center">53</td><td class="align_center">64</td></tr><tr class="table-tr"><td colspan="7"><hr class="tbody-hr"/></td></tr></table></td></tr></table>

<div>CCD test design factors and coding values.</div>

Shock and Vibration

tab8

Table 8

Table 8: Experimental Study on Lateral Resolution of Phased Array Ultrasonic Testing of Irregular Structure Weld Defects 