Crack Closure Effects on Fatigue Crack Propagation Rates: Application of a Proposed Theoretical Model

<div>Relationship between effective stress ratio, <svg height="11.9316pt" id="M196" style="vertical-align:-3.2957pt" version="1.1" viewbox="-0.0498162 -8.6359 18.7433 11.9316" width="18.7433pt" 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="M610 18C585 26 567 34 540 68C517 97 499 128 476 171C452 215 425 276 413 304C496 332 570 394 570 494C570 555 545 595 509 619S419 650 364 650H139L133 622C216 615 219 612 203 527L129 132C112 40 105 36 23 28L17 0H279L285 28C199 34 194 40 211 132L239 284H284C320 284 334 275 351 236C374 182 394 140 420 93C459 23 495 -1 592 -8H600L610 18ZM480 485C480 424 449 372 403 342C374 323 338 316 293 316H245L291 562C296 589 301 601 311 608S337 618 358 618C432 618 480 575 480 485Z" id="g113-83"></path><glyph.data ascent="3473" descent="-2876" horiz-adv-x="627" vert-adv-y="627"></glyph.data></g><g transform="matrix(.0091,0,0,-0.0091,8.086,3.132)"><path d="M384 109C349 76 310 59 268 59C197 59 123 113 120 245C240 248 367 259 384 262C403 266 407 275 407 296C407 376 338 451 254 451H253C201 451 148 425 105 378C65 334 39 272 39 203C39 88 112 -12 235 -12C266 -12 339 5 402 84L384 109ZM230 411C285 411 319 365 319 313C319 298 313 293 294 293C236 291 180 290 125 290C141 370 185 411 230 411Z" id="g58-99"></path><glyph.data ascent="1007" descent="-369" horiz-adv-x="434" vert-adv-y="434"></glyph.data></g><g transform="matrix(.0091,0,0,-0.0091,12.035,3.132)"><path d="M100 439H52L25 408L28 396H100V106C100 41 92 35 31 30V0H250V29C188 37 181 41 181 106V396H372V107C372 40 365 37 309 29V0H537V29C461 37 453 40 453 106V396H564C576 403 579 428 574 439H453V469C452 558 462 604 474 623S500 656 527 656C562 656 589 634 608 615C619 604 628 607 639 615C647 622 658 633 661 641C666 653 664 664 656 674C637 696 609 708 572 710C528 703 483 682 439 638C418 661 380 685 320 688C269 683 230 666 190 633C139 593 122 550 113 525S100 476 100 451V439ZM372 439H181V461C181 530 194 571 211 598C226 621 248 643 287 643C343 643 379 607 400 578C391 561 384 546 381 529C376 510 372 486 372 457V439Z" id="g58-26"></path><glyph.data ascent="1007" descent="-369" horiz-adv-x="572" vert-adv-y="572"></glyph.data></g></svg>, and applied stress intensity range, <svg height="8.68572pt" id="M197" style="vertical-align:-0.0498209pt" version="1.1" viewbox="-0.0498162 -8.6359 18.3157 8.68572" width="18.3157pt" 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="M600 0V24L339 665L311 657L43 24V0H600ZM497 50H107L303 539L497 50Z" id="g113-133"></path><glyph.data ascent="3473" descent="-2876" horiz-adv-x="641" vert-adv-y="641"></glyph.data></g><g transform="matrix(.013,0,0,-0.013,8.327,0)"><path d="M743 650H503L496 622L527 618C563 613 564 603 532 573C449 495 371 431 323 392C301 374 272 355 246 346L280 522C297 609 300 614 379 622L385 650H135L129 622C209 614 215 609 198 522L124 133C106 39 99 35 23 28L17 0H271L277 28C193 35 192 39 208 133L239 316C264 328 280 325 303 288C368 183 435 90 502 0H652L659 28C602 34 584 43 543 94C495 154 403 283 347 369L574 554C634 603 659 612 735 624L743 650Z" id="g113-76"></path><glyph.data ascent="3473" descent="-2876" horiz-adv-x="755" vert-adv-y="755"></glyph.data></g></svg> (P355NL1 steel).</div>

Advances in Materials Science and Engineering

fig8

Figure 8

Figure 8: Crack Closure Effects on Fatigue Crack Propagation Rates: Application of a Proposed Theoretical Model 