How does ideCAD control the maximum spacing of moderately ductile beams according to AISC 341-16?
Maximum spacing of beam bracing systems is controlled automatically and reported with steel beam reports.
Symbols
Fy = Specified minimum yield stress
Ry = Ratio of the expected yield stress to the specified minimum yield stress, Fy
Lb = Length between points which are either braced against lateral displacement of compression flange or braced against twist of the cross-section, in. (mm)
ry = Radius of gyration about y-axis, in. (mm)
E= Modulus of elasticity of steel = 29000 ksi (200000 MPa)
Steel Beams
The bracing of moderately ductile steel beams should provide a maximum spacing given the equation below.
 %5c%3b %5c%3b %5c%3b %5c%3b %5c%3b%5c%3b%5c%3b%5c%3b%5c%3b %5c%3b %5c%3b %5c%3b %5c%3b %5c%3b%5c%3b%5c%3b%5c%3b%5c%3b %5c%3b %5c%3b %5c%3b %5c%3b %5c%3b%5c%3b%5c%3b%5c%3b%5c%3b %5c%3b %5c%3b %5c%3b %5c%3b %5c%3b%5c%3b%5c%3b%5c%3b%5c%3b (D1-2)%5cend%7barray%7d%3c/title%3e %3cdefs aria-hidden='true'%3e %3cpath stroke-width='1' id='E1-MJMATHI-4C' d='M228 637Q194 637 192 641Q191 643 191 649Q191 673 202 682Q204 683 217 683Q271 680 344 680Q485 680 506 683H518Q524 677 524 674T522 656Q517 641 513 637H475Q406 636 394 628Q387 624 380 600T313 336Q297 271 279 198T252 88L243 52Q243 48 252 48T311 46H328Q360 46 379 47T428 54T478 72T522 106T564 161Q580 191 594 228T611 270Q616 273 628 273H641Q647 264 647 262T627 203T583 83T557 9Q555 4 553 3T537 0T494 -1Q483 -1 418 -1T294 0H116Q32 0 32 10Q32 17 34 24Q39 43 44 45Q48 46 59 46H65Q92 46 125 49Q139 52 144 61Q147 65 216 339T285 628Q285 635 228 637Z'%3e%3c/path%3e %3cpath stroke-width='1' id='E1-MJMATHI-62' d='M73 647Q73 657 77 670T89 683Q90 683 161 688T234 694Q246 694 246 685T212 542Q204 508 195 472T180 418L176 399Q176 396 182 402Q231 442 283 442Q345 442 383 396T422 280Q422 169 343 79T173 -11Q123 -11 82 27T40 150V159Q40 180 48 217T97 414Q147 611 147 623T109 637Q104 637 101 637H96Q86 637 83 637T76 640T73 647ZM336 325V331Q336 405 275 405Q258 405 240 397T207 376T181 352T163 330L157 322L136 236Q114 150 114 114Q114 66 138 42Q154 26 178 26Q211 26 245 58Q270 81 285 114T318 219Q336 291 336 325Z'%3e%3c/path%3e %3cpath stroke-width='1' id='E1-MJMAIN-3D' d='M56 347Q56 360 70 367H707Q722 359 722 347Q722 336 708 328L390 327H72Q56 332 56 347ZM56 153Q56 168 72 173H708Q722 163 722 153Q722 140 707 133H70Q56 140 56 153Z'%3e%3c/path%3e %3cpath stroke-width='1' id='E1-MJMAIN-30' d='M96 585Q152 666 249 666Q297 666 345 640T423 548Q460 465 460 320Q460 165 417 83Q397 41 362 16T301 -15T250 -22Q224 -22 198 -16T137 16T82 83Q39 165 39 320Q39 494 96 585ZM321 597Q291 629 250 629Q208 629 178 597Q153 571 145 525T137 333Q137 175 145 125T181 46Q209 16 250 16Q290 16 318 46Q347 76 354 130T362 333Q362 478 354 524T321 597Z'%3e%3c/path%3e %3cpath stroke-width='1' id='E1-MJMAIN-2E' d='M78 60Q78 84 95 102T138 120Q162 120 180 104T199 61Q199 36 182 18T139 0T96 17T78 60Z'%3e%3c/path%3e %3cpath stroke-width='1' id='E1-MJMAIN-31' d='M213 578L200 573Q186 568 160 563T102 556H83V602H102Q149 604 189 617T245 641T273 663Q275 666 285 666Q294 666 302 660V361L303 61Q310 54 315 52T339 48T401 46H427V0H416Q395 3 257 3Q121 3 100 0H88V46H114Q136 46 152 46T177 47T193 50T201 52T207 57T213 61V578Z'%3e%3c/path%3e %3cpath stroke-width='1' id='E1-MJMAIN-39' d='M352 287Q304 211 232 211Q154 211 104 270T44 396Q42 412 42 436V444Q42 537 111 606Q171 666 243 666Q245 666 249 666T257 665H261Q273 665 286 663T323 651T370 619T413 560Q456 472 456 334Q456 194 396 97Q361 41 312 10T208 -22Q147 -22 108 7T68 93T121 149Q143 149 158 135T173 96Q173 78 164 65T148 49T135 44L131 43Q131 41 138 37T164 27T206 22H212Q272 22 313 86Q352 142 352 280V287ZM244 248Q292 248 321 297T351 430Q351 508 343 542Q341 552 337 562T323 588T293 615T246 625Q208 625 181 598Q160 576 154 546T147 441Q147 358 152 329T172 282Q197 248 244 248Z'%3e%3c/path%3e %3cpath stroke-width='1' id='E1-MJMATHI-72' d='M21 287Q22 290 23 295T28 317T38 348T53 381T73 411T99 433T132 442Q161 442 183 430T214 408T225 388Q227 382 228 382T236 389Q284 441 347 441H350Q398 441 422 400Q430 381 430 363Q430 333 417 315T391 292T366 288Q346 288 334 299T322 328Q322 376 378 392Q356 405 342 405Q286 405 239 331Q229 315 224 298T190 165Q156 25 151 16Q138 -11 108 -11Q95 -11 87 -5T76 7T74 17Q74 30 114 189T154 366Q154 405 128 405Q107 405 92 377T68 316T57 280Q55 278 41 278H27Q21 284 21 287Z'%3e%3c/path%3e %3cpath stroke-width='1' id='E1-MJMATHI-79' d='M21 287Q21 301 36 335T84 406T158 442Q199 442 224 419T250 355Q248 336 247 334Q247 331 231 288T198 191T182 105Q182 62 196 45T238 27Q261 27 281 38T312 61T339 94Q339 95 344 114T358 173T377 247Q415 397 419 404Q432 431 462 431Q475 431 483 424T494 412T496 403Q496 390 447 193T391 -23Q363 -106 294 -155T156 -205Q111 -205 77 -183T43 -117Q43 -95 50 -80T69 -58T89 -48T106 -45Q150 -45 150 -87Q150 -107 138 -122T115 -142T102 -147L99 -148Q101 -153 118 -160T152 -167H160Q177 -167 186 -165Q219 -156 247 -127T290 -65T313 -9T321 21L315 17Q309 13 296 6T270 -6Q250 -11 231 -11Q185 -11 150 11T104 82Q103 89 103 113Q103 170 138 262T173 379Q173 380 173 381Q173 390 173 393T169 400T158 404H154Q131 404 112 385T82 344T65 302T57 280Q55 278 41 278H27Q21 284 21 287Z'%3e%3c/path%3e %3cpath stroke-width='1' id='E1-MJMATHI-45' d='M492 213Q472 213 472 226Q472 230 477 250T482 285Q482 316 461 323T364 330H312Q311 328 277 192T243 52Q243 48 254 48T334 46Q428 46 458 48T518 61Q567 77 599 117T670 248Q680 270 683 272Q690 274 698 274Q718 274 718 261Q613 7 608 2Q605 0 322 0H133Q31 0 31 11Q31 13 34 25Q38 41 42 43T65 46Q92 46 125 49Q139 52 144 61Q146 66 215 342T285 622Q285 629 281 629Q273 632 228 634H197Q191 640 191 642T193 659Q197 676 203 680H757Q764 676 764 669Q764 664 751 557T737 447Q735 440 717 440H705Q698 445 698 453L701 476Q704 500 704 528Q704 558 697 578T678 609T643 625T596 632T532 634H485Q397 633 392 631Q388 629 386 622Q385 619 355 499T324 377Q347 376 372 376H398Q464 376 489 391T534 472Q538 488 540 490T557 493Q562 493 565 493T570 492T572 491T574 487T577 483L544 351Q511 218 508 216Q505 213 492 213Z'%3e%3c/path%3e %3cpath stroke-width='1' id='E1-MJMAIN-2F' d='M423 750Q432 750 438 744T444 730Q444 725 271 248T92 -240Q85 -250 75 -250Q68 -250 62 -245T56 -231Q56 -221 230 257T407 740Q411 750 423 750Z'%3e%3c/path%3e %3cpath stroke-width='1' id='E1-MJMAIN-28' d='M94 250Q94 319 104 381T127 488T164 576T202 643T244 695T277 729T302 750H315H319Q333 750 333 741Q333 738 316 720T275 667T226 581T184 443T167 250T184 58T225 -81T274 -167T316 -220T333 -241Q333 -250 318 -250H315H302L274 -226Q180 -141 137 -14T94 250Z'%3e%3c/path%3e %3cpath stroke-width='1' id='E1-MJMATHI-52' d='M230 637Q203 637 198 638T193 649Q193 676 204 682Q206 683 378 683Q550 682 564 680Q620 672 658 652T712 606T733 563T739 529Q739 484 710 445T643 385T576 351T538 338L545 333Q612 295 612 223Q612 212 607 162T602 80V71Q602 53 603 43T614 25T640 16Q668 16 686 38T712 85Q717 99 720 102T735 105Q755 105 755 93Q755 75 731 36Q693 -21 641 -21H632Q571 -21 531 4T487 82Q487 109 502 166T517 239Q517 290 474 313Q459 320 449 321T378 323H309L277 193Q244 61 244 59Q244 55 245 54T252 50T269 48T302 46H333Q339 38 339 37T336 19Q332 6 326 0H311Q275 2 180 2Q146 2 117 2T71 2T50 1Q33 1 33 10Q33 12 36 24Q41 43 46 45Q50 46 61 46H67Q94 46 127 49Q141 52 146 61Q149 65 218 339T287 628Q287 635 230 637ZM630 554Q630 586 609 608T523 636Q521 636 500 636T462 637H440Q393 637 386 627Q385 624 352 494T319 361Q319 360 388 360Q466 361 492 367Q556 377 592 426Q608 449 619 486T630 554Z'%3e%3c/path%3e %3cpath stroke-width='1' id='E1-MJMATHI-46' d='M48 1Q31 1 31 11Q31 13 34 25Q38 41 42 43T65 46Q92 46 125 49Q139 52 144 61Q146 66 215 342T285 622Q285 629 281 629Q273 632 228 634H197Q191 640 191 642T193 659Q197 676 203 680H742Q749 676 749 669Q749 664 736 557T722 447Q720 440 702 440H690Q683 445 683 453Q683 454 686 477T689 530Q689 560 682 579T663 610T626 626T575 633T503 634H480Q398 633 393 631Q388 629 386 623Q385 622 352 492L320 363H375Q378 363 398 363T426 364T448 367T472 374T489 386Q502 398 511 419T524 457T529 475Q532 480 548 480H560Q567 475 567 470Q567 467 536 339T502 207Q500 200 482 200H470Q463 206 463 212Q463 215 468 234T473 274Q473 303 453 310T364 317H309L277 190Q245 66 245 60Q245 46 334 46H359Q365 40 365 39T363 19Q359 6 353 0H336Q295 2 185 2Q120 2 86 2T48 1Z'%3e%3c/path%3e %3cpath stroke-width='1' id='E1-MJMAIN-29' d='M60 749L64 750Q69 750 74 750H86L114 726Q208 641 251 514T294 250Q294 182 284 119T261 12T224 -76T186 -143T145 -194T113 -227T90 -246Q87 -249 86 -250H74Q66 -250 63 -250T58 -247T55 -238Q56 -237 66 -225Q221 -64 221 250T66 725Q56 737 55 738Q55 746 60 749Z'%3e%3c/path%3e %3cpath stroke-width='1' id='E1-MJMATHI-44' d='M287 628Q287 635 230 637Q207 637 200 638T193 647Q193 655 197 667T204 682Q206 683 403 683Q570 682 590 682T630 676Q702 659 752 597T803 431Q803 275 696 151T444 3L430 1L236 0H125H72Q48 0 41 2T33 11Q33 13 36 25Q40 41 44 43T67 46Q94 46 127 49Q141 52 146 61Q149 65 218 339T287 628ZM703 469Q703 507 692 537T666 584T629 613T590 629T555 636Q553 636 541 636T512 636T479 637H436Q392 637 386 627Q384 623 313 339T242 52Q242 48 253 48T330 47Q335 47 349 47T373 46Q499 46 581 128Q617 164 640 212T683 339T703 469Z'%3e%3c/path%3e %3cpath stroke-width='1' id='E1-MJMAIN-2212' d='M84 237T84 250T98 270H679Q694 262 694 250T679 230H98Q84 237 84 250Z'%3e%3c/path%3e %3cpath stroke-width='1' id='E1-MJMAIN-32' d='M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z'%3e%3c/path%3e %3c/defs%3e %3cg stroke='currentColor' fill='currentColor' stroke-width='0' transform='matrix(1 0 0 -1 0 0)' aria-hidden='true'%3e %3cg transform='translate(167%2c0)'%3e %3cg transform='translate(-11%2c0)'%3e %3cg transform='translate(0%2c-3)'%3e %3cuse xlink:href='%23E1-MJMATHI-4C' x='0' y='0'%3e%3c/use%3e %3cuse transform='scale(0.707)' xlink:href='%23E1-MJMATHI-62' x='963' y='-213'%3e%3c/use%3e %3cuse xlink:href='%23E1-MJMAIN-3D' x='1362' y='0'%3e%3c/use%3e %3cg transform='translate(2419%2c0)'%3e %3cuse xlink:href='%23E1-MJMAIN-30'%3e%3c/use%3e %3cuse xlink:href='%23E1-MJMAIN-2E' x='500' y='0'%3e%3c/use%3e %3cuse xlink:href='%23E1-MJMAIN-31' x='779' y='0'%3e%3c/use%3e %3cuse xlink:href='%23E1-MJMAIN-39' x='1279' y='0'%3e%3c/use%3e %3c/g%3e %3cg transform='translate(4199%2c0)'%3e %3cuse xlink:href='%23E1-MJMATHI-72' x='0' y='0'%3e%3c/use%3e %3cuse transform='scale(0.707)' xlink:href='%23E1-MJMATHI-79' x='638' y='-213'%3e%3c/use%3e %3c/g%3e %3cuse xlink:href='%23E1-MJMATHI-45' x='5102' y='0'%3e%3c/use%3e %3cuse xlink:href='%23E1-MJMAIN-2F' x='5867' y='0'%3e%3c/use%3e %3cuse xlink:href='%23E1-MJMAIN-28' x='6367' y='0'%3e%3c/use%3e %3cg transform='translate(6757%2c0)'%3e %3cuse xlink:href='%23E1-MJMATHI-52' x='0' y='0'%3e%3c/use%3e %3cuse transform='scale(0.707)' xlink:href='%23E1-MJMATHI-79' x='1074' y='-213'%3e%3c/use%3e %3c/g%3e %3cg transform='translate(7968%2c0)'%3e %3cuse xlink:href='%23E1-MJMATHI-46' x='0' y='0'%3e%3c/use%3e %3cuse transform='scale(0.707)' xlink:href='%23E1-MJMATHI-79' x='910' y='-213'%3e%3c/use%3e %3c/g%3e %3cuse xlink:href='%23E1-MJMAIN-29' x='9063' y='0'%3e%3c/use%3e %3cuse xlink:href='%23E1-MJMAIN-28' x='19453' y='0'%3e%3c/use%3e %3cuse xlink:href='%23E1-MJMATHI-44' x='19842' y='0'%3e%3c/use%3e %3cuse xlink:href='%23E1-MJMAIN-31' x='20671' y='0'%3e%3c/use%3e %3cuse xlink:href='%23E1-MJMAIN-2212' x='21393' y='0'%3e%3c/use%3e %3cuse xlink:href='%23E1-MJMAIN-32' x='22394' y='0'%3e%3c/use%3e %3cuse xlink:href='%23E1-MJMAIN-29' x='22895' y='0'%3e%3c/use%3e %3c/g%3e %3c/g%3e %3c/g%3e %3c/g%3e %3c/svg%3e)
