Scale Effect on the Anisotropy of Acoustic Emission in Coal

<table class="table-group" id="tab2"><tr><td><table class="table"><tr><td class="thead-hr" colspan="5"><hr/></td></tr><tr class="thead"><td class="align_left">Specimen diameter (mm)</td><td class="align_center">25</td><td class="align_center">38</td><td class="align_center">50</td><td class="align_center">75</td></tr><tr><td class="thead-hr" colspan="5"><hr/></td></tr><tr><td class="align_left">Average value (10<sup>9</sup>aJ)</td><td class="align_center">1.35</td><td class="align_center">1.55</td><td class="align_center">1.86</td><td class="align_center">2.75</td></tr><tr><td class="align_left">Coefficient of variation</td><td class="align_center">0.151</td><td class="align_center">0.133</td><td class="align_center">0.116</td><td class="align_center">0.057</td></tr><tr class="table-tr"><td colspan="5"><hr class="tbody-hr"/></td></tr></table></td></tr></table>

<div>The variation of cumulative absolute AE energy in the specimens with different sizes.</div>

Shock and Vibration

Scale Effect on the Anisotropy of Acoustic Emission in Coal

Table 2