Experimental Investigations on Electrical Charge of Precracked Rock Specimens under Uniaxial Compression

<table class="table-group" id="tab3"><tr><td><table class="table"><tr><td class="thead-hr" colspan="5"><hr/></td></tr><tr class="thead"><td class="align_left">Sample</td><td class="align_center">Precrack inclination angle</td><td class="align_center">Final charge accumulation (10<sup>4</sup> pC)</td><td class="align_center">Crack surface friction factor</td><td class="align_center">Secondary crack growth angle</td></tr><tr><td class="thead-hr" colspan="5"><hr/></td></tr><tr><td class="align_left">Sample 1</td><td class="align_center">0</td><td class="align_center">3.04</td><td class="align_center">0.13</td><td class="align_center">−70°</td></tr><tr><td class="align_left">Sample 2</td><td class="align_center"><span style="width: 19.4509ptpx;"><svg height="11.439pt" id="M36" style="vertical-align:-2.15067pt" version="1.1" viewbox="-0.0498162 -9.28833 19.4509 11.439" width="19.4509pt" 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="M574 449L545 460C526 432 516 430 487 430C404 430 311 435 226 435C104 435 56 379 25 341L43 318C81 354 121 372 181 372C161 246 87 53 23 3L30 -12C48 -12 88 -4 113 11C157 75 207 248 232 371L386 367L326 109C321 86 318 66 318 50C318 4 339 -12 366 -12C410 -12 461 21 505 69L492 96C467 79 434 60 418 60C406 60 400 78 411 147C422 217 439 300 457 366C487 366 524 367 536 370C547 385 558 408 574 449Z"></path></g><g transform="matrix(.013,0,0,-0.013,7.684,0)"><path d="M368 703H309L44 -163H104L368 703Z"></path></g><g transform="matrix(.013,0,0,-0.013,13.045,0)"><path d="M137 343C167 482 260 545 321 574C357 591 397 603 429 609L423 641C382 634 335 622 295 608C189 570 37 457 37 238C37 84 125 -12 242 -12C362 -12 447 89 447 209C447 311 374 393 267 393C247 393 226 386 204 376L137 343ZM227 337C318 337 361 256 361 173C361 105 336 22 258 22C176 22 126 120 126 240C126 266 127 291 132 310C155 323 189 337 227 337Z"></path></g></svg></span></td><td class="align_center">3.28</td><td class="align_center">0.18</td><td class="align_center">−59°</td></tr><tr><td class="align_left">Sample 3</td><td class="align_center"><span style="width: 19.4509ptpx;"><svg height="11.439pt" id="M37" style="vertical-align:-2.15067pt" version="1.1" viewbox="-0.0498162 -9.28833 19.4509 11.439" width="19.4509pt" 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="M574 449L545 460C526 432 516 430 487 430C404 430 311 435 226 435C104 435 56 379 25 341L43 318C81 354 121 372 181 372C161 246 87 53 23 3L30 -12C48 -12 88 -4 113 11C157 75 207 248 232 371L386 367L326 109C321 86 318 66 318 50C318 4 339 -12 366 -12C410 -12 461 21 505 69L492 96C467 79 434 60 418 60C406 60 400 78 411 147C422 217 439 300 457 366C487 366 524 367 536 370C547 385 558 408 574 449Z"></path></g><g transform="matrix(.013,0,0,-0.013,7.684,0)"><path d="M368 703H309L44 -163H104L368 703Z"></path></g><g transform="matrix(.013,0,0,-0.013,13.045,0)"><path d="M456 178V225H360V632H320C217 496 115 347 20 206V178H280V106C280 40 276 34 189 27V0H445V27C364 34 360 39 360 106V178H456ZM280 225H82C149 335 214 431 278 520H280V225Z"></path></g></svg></span></td><td class="align_center">4.09</td><td class="align_center">0.23</td><td class="align_center">−49°</td></tr><tr><td class="align_left">Sample 4</td><td class="align_center"><span style="width: 19.4509ptpx;"><svg height="11.439pt" id="M38" style="vertical-align:-2.15067pt" version="1.1" viewbox="-0.0498162 -9.28833 19.4509 11.439" width="19.4509pt" 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="M574 449L545 460C526 432 516 430 487 430C404 430 311 435 226 435C104 435 56 379 25 341L43 318C81 354 121 372 181 372C161 246 87 53 23 3L30 -12C48 -12 88 -4 113 11C157 75 207 248 232 371L386 367L326 109C321 86 318 66 318 50C318 4 339 -12 366 -12C410 -12 461 21 505 69L492 96C467 79 434 60 418 60C406 60 400 78 411 147C422 217 439 300 457 366C487 366 524 367 536 370C547 385 558 408 574 449Z"></path></g><g transform="matrix(.013,0,0,-0.013,7.684,0)"><path d="M368 703H309L44 -163H104L368 703Z"></path></g><g transform="matrix(.013,0,0,-0.013,13.045,0)"><path d="M285 378C315 398 338 416 353 432C373 451 384 474 384 503C384 579 325 635 236 635H235C182 635 136 610 108 579L65 516L85 496C110 533 150 575 205 575C258 575 300 543 300 481C300 407 232 369 141 339L147 310C163 315 188 321 211 321C268 321 338 284 338 192C338 94 288 40 217 40C160 40 119 68 93 91C85 98 77 97 69 91C60 84 47 71 46 58C44 46 48 35 62 22C75 10 116 -12 162 -12C234 -12 424 62 424 224C424 297 373 359 285 376V378Z"></path></g></svg></span></td><td class="align_center">0.97</td><td class="align_center">0.088</td><td class="align_center">−52°</td></tr><tr><td class="align_left">Sample 5</td><td class="align_center"><span style="width: 19.4509ptpx;"><svg height="11.439pt" id="M39" style="vertical-align:-2.15067pt" version="1.1" viewbox="-0.0498162 -9.28833 19.4509 11.439" width="19.4509pt" 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="M574 449L545 460C526 432 516 430 487 430C404 430 311 435 226 435C104 435 56 379 25 341L43 318C81 354 121 372 181 372C161 246 87 53 23 3L30 -12C48 -12 88 -4 113 11C157 75 207 248 232 371L386 367L326 109C321 86 318 66 318 50C318 4 339 -12 366 -12C410 -12 461 21 505 69L492 96C467 79 434 60 418 60C406 60 400 78 411 147C422 217 439 300 457 366C487 366 524 367 536 370C547 385 558 408 574 449Z"></path></g><g transform="matrix(.013,0,0,-0.013,7.684,0)"><path d="M368 703H309L44 -163H104L368 703Z"></path></g><g transform="matrix(.013,0,0,-0.013,13.045,0)"><path d="M412 140C382 77 369 73 315 73H129L270 222C362 320 402 379 402 466C402 571 322 635 234 635C177 635 130 609 99 576L42 495L64 475C90 514 133 568 201 568C274 568 318 519 318 435C318 349 255 267 193 193C144 135 87 78 32 23V0H405C417 45 427 89 440 131L412 140Z"></path></g></svg></span></td><td class="align_center">1.17</td><td class="align_center">0.094</td><td class="align_center">−90°</td></tr><tr class="table-tr"><td colspan="5"><hr class="tbody-hr"/></td></tr></table></td></tr></table>

<div>Crack surface friction factors and secondary crack growth angles for different samples.</div>

Shock and Vibration

tab3

Table 3

Table 3: Experimental Investigations on Electrical Charge of Precracked Rock Specimens under Uniaxial Compression 