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

<table class="table-group" id="tab5"><tr><td><table class="table"><tr><td class="thead-hr" colspan="5"><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="3">Coding</td></tr><tr class="thead"><td class="align_center">−1</td><td class="align_center">0</td><td class="align_center">1</td></tr><tr><td class="thead-hr" colspan="5"><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">7</td><td class="align_center">10</td><td class="align_center">13</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">18</td><td class="align_center">30</td><td class="align_center">42</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">19</td><td class="align_center">36</td><td class="align_center">53</td></tr><tr class="table-tr"><td colspan="5"><hr class="tbody-hr"/></td></tr></table></td></tr></table>

<div>Three-factor three-level coding.</div>

Shock and Vibration

tab5

Table 5

Table 5: Experimental Study on Lateral Resolution of Phased Array Ultrasonic Testing of Irregular Structure Weld Defects 