Knowledge (XXG)

Moment-area theorem

Source đź“ť

854: 254:
The vertical deviation of a point A on an elastic curve with respect to the tangent which is extended from another point B equals the moment of the area under the M/EI diagram between those two points (A and B). This moment is computed about point A where the deviation from B to A is to be
465:
The deviation at any point on the elastic curve is positive if the point lies above the tangent, negative if the point is below the tangent; we measured it from left tangent, if θ is counterclockwise direction, the change in slope is positive, negative if θ is clockwise direction.
127: 338: 599: 28:
in 1873. This method is advantageous when we solve problems involving beams, especially for those subjected to a series of concentrated loadings or having segments with different
474:
The following procedure provides a method that may be used to determine the displacement and slope at a point on the elastic curve of a beam using the moment-area theorem.
215: 426: 454: 243: 389: 178: 671: 364: 153: 481:
If there are only concentrated loads on the structure, the problem will be easy to draw M/EI diagram which will results a series of triangular shapes.
46: 585: 542: 517: 839: 557: 40:
The change in slope between any two points on the elastic curve equals the area of the M/EI (moment) diagram between these two points.
619: 592: 261: 824: 484:
If there are mixed with distributed loads and concentrated, the moment diagram (M/EI) will results parabolic curves, cubic, etc.
857: 883: 20:
is an engineering tool to derive the slope, rotation and deflection of beams and frames. This theorem was developed by
878: 701: 696: 829: 691: 661: 804: 608: 490:
Find the rotations, change of slopes and deflections of the structure by using the geometric mathematics.
666: 635: 786: 681: 572: 185: 25: 21: 796: 755: 748: 711: 676: 29: 656: 765: 538: 513: 396: 726: 741: 433: 222: 478:
Determine the reaction forces of a structure and draw the M/EI diagram of the structure.
371: 160: 640: 487:
Then, assume and draw the deflection shape of the structure by looking at M/EI diagram.
349: 138: 872: 834: 122:{\displaystyle \theta _{A/B}={\int _{A}}^{B}\left({\frac {M}{EI}}\right)dx} 577: 428:= deviation of tangent at point A with respect to the tangent at point B 736: 731: 760: 781: 581: 333:{\displaystyle t_{A/B}={\int _{A}}^{B}{\frac {M}{EI}}x\;dx} 436: 399: 374: 352: 264: 225: 188: 163: 141: 49: 537:(8th ed.). Boston: Prentice Hall. p. 317. 512:(8th ed.). Boston: Prentice Hall. p. 316. 817: 795: 774: 719: 710: 649: 628: 448: 420: 383: 358: 332: 237: 209: 172: 147: 121: 593: 8: 716: 600: 586: 578: 323: 435: 408: 404: 398: 373: 351: 305: 299: 292: 287: 273: 269: 263: 224: 197: 193: 187: 162: 140: 94: 84: 77: 72: 58: 54: 48: 217:= change in slope between points A and B 500: 7: 558:Moment-Area Method Beam Deflection 14: 853: 852: 840:Timoshenko–Ehrenfest beam theory 1: 456:= points on the elastic curve 245:= points on the elastic curve 210:{\displaystyle \theta _{A/B}} 825:Euler–Bernoulli beam theory 24:and later stated namely by 900: 573:Area-Moment Method. (n.d.) 848: 615: 702:Theorem of three moments 697:Shear and moment diagram 533:Hibbeler, R. C. (2012). 508:Hibbeler, R. C. (2012). 461:Rule of sign convention 421:{\displaystyle t_{A/B}} 609:Structural engineering 470:Procedure for analysis 450: 422: 385: 360: 334: 239: 211: 174: 149: 123: 667:Conjugate beam method 451: 423: 386: 361: 335: 240: 212: 175: 150: 124: 787:Thin-shell structure 662:Castigliano's method 434: 397: 372: 350: 262: 223: 186: 161: 139: 47: 884:Structural analysis 830:Mohr–Coulomb theory 712:Structural elements 687:Moment-area theorem 535:Structural analysis 510:Structural analysis 449:{\displaystyle A,B} 391:= flexural rigidity 238:{\displaystyle A,B} 180:= flexural rigidity 26:Charles Ezra Greene 18:moment-area theorem 797:Structural support 756:Compression member 677:Flexibility method 636:Duhamel's integral 446: 418: 384:{\displaystyle EI} 381: 356: 330: 235: 207: 173:{\displaystyle EI} 170: 145: 119: 30:moments of inertia 866: 865: 813: 812: 682:Macaulay's method 544:978-0-13-257053-4 519:978-0-13-257053-4 359:{\displaystyle M} 318: 148:{\displaystyle M} 107: 891: 879:Moment (physics) 856: 855: 717: 692:Stiffness method 629:Dynamic analysis 602: 595: 588: 579: 560: 555: 549: 548: 530: 524: 523: 505: 455: 453: 452: 447: 427: 425: 424: 419: 417: 416: 412: 390: 388: 387: 382: 365: 363: 362: 357: 339: 337: 336: 331: 319: 317: 306: 304: 303: 298: 297: 296: 282: 281: 277: 244: 242: 241: 236: 216: 214: 213: 208: 206: 205: 201: 179: 177: 176: 171: 154: 152: 151: 146: 128: 126: 125: 120: 112: 108: 106: 95: 89: 88: 83: 82: 81: 67: 66: 62: 899: 898: 894: 893: 892: 890: 889: 888: 869: 868: 867: 862: 844: 809: 791: 770: 742:Post and lintel 706: 657:Betti's theorem 650:Static analysis 645: 624: 611: 606: 569: 564: 563: 556: 552: 545: 532: 531: 527: 520: 507: 506: 502: 497: 472: 463: 432: 431: 400: 395: 394: 370: 369: 348: 347: 310: 288: 286: 265: 260: 259: 252: 221: 220: 189: 184: 183: 159: 158: 137: 136: 99: 90: 73: 71: 50: 45: 44: 38: 12: 11: 5: 897: 895: 887: 886: 881: 871: 870: 864: 863: 861: 860: 849: 846: 845: 843: 842: 837: 832: 827: 821: 819: 815: 814: 811: 810: 808: 807: 801: 799: 793: 792: 790: 789: 784: 778: 776: 772: 771: 769: 768: 763: 758: 753: 752: 751: 746: 745: 744: 734: 723: 721: 714: 708: 707: 705: 704: 699: 694: 689: 684: 679: 674: 669: 664: 659: 653: 651: 647: 646: 644: 643: 641:Modal analysis 638: 632: 630: 626: 625: 623: 622: 616: 613: 612: 607: 605: 604: 597: 590: 582: 576: 575: 568: 567:External links 565: 562: 561: 550: 543: 525: 518: 499: 498: 496: 493: 492: 491: 488: 485: 482: 479: 471: 468: 462: 459: 458: 457: 445: 442: 439: 429: 415: 411: 407: 403: 392: 380: 377: 367: 355: 341: 340: 329: 326: 322: 316: 313: 309: 302: 295: 291: 285: 280: 276: 272: 268: 251: 248: 247: 246: 234: 231: 228: 218: 204: 200: 196: 192: 181: 169: 166: 156: 144: 130: 129: 118: 115: 111: 105: 102: 98: 93: 87: 80: 76: 70: 65: 61: 57: 53: 37: 34: 13: 10: 9: 6: 4: 3: 2: 896: 885: 882: 880: 877: 876: 874: 859: 851: 850: 847: 841: 838: 836: 833: 831: 828: 826: 823: 822: 820: 816: 806: 803: 802: 800: 798: 794: 788: 785: 783: 780: 779: 777: 775:2-dimensional 773: 767: 764: 762: 759: 757: 754: 750: 747: 743: 740: 739: 738: 735: 733: 730: 729: 728: 725: 724: 722: 720:1-dimensional 718: 715: 713: 709: 703: 700: 698: 695: 693: 690: 688: 685: 683: 680: 678: 675: 673: 670: 668: 665: 663: 660: 658: 655: 654: 652: 648: 642: 639: 637: 634: 633: 631: 627: 621: 618: 617: 614: 610: 603: 598: 596: 591: 589: 584: 583: 580: 574: 571: 570: 566: 559: 554: 551: 546: 540: 536: 529: 526: 521: 515: 511: 504: 501: 494: 489: 486: 483: 480: 477: 476: 475: 469: 467: 460: 443: 440: 437: 430: 413: 409: 405: 401: 393: 378: 375: 368: 353: 346: 345: 344: 327: 324: 320: 314: 311: 307: 300: 293: 289: 283: 278: 274: 270: 266: 258: 257: 256: 249: 232: 229: 226: 219: 202: 198: 194: 190: 182: 167: 164: 157: 142: 135: 134: 133: 116: 113: 109: 103: 100: 96: 91: 85: 78: 74: 68: 63: 59: 55: 51: 43: 42: 41: 35: 33: 31: 27: 23: 19: 835:Plate theory 686: 553: 534: 528: 509: 503: 473: 464: 342: 255:determined. 253: 131: 39: 17: 15: 873:Categories 495:References 290:∫ 250:Theorem 2 191:θ 75:∫ 52:θ 36:Theorem 1 858:Category 818:Theories 366:= moment 155:= moment 805:Bracket 620:History 343:where, 132:where, 737:Lintel 732:I-beam 541:  516:  761:Strut 782:Arch 749:Span 727:Beam 539:ISBN 514:ISBN 22:Mohr 16:The 766:Tie 672:FEM 875:: 32:. 601:e 594:t 587:v 547:. 522:. 444:B 441:, 438:A 414:B 410:/ 406:A 402:t 379:I 376:E 354:M 328:x 325:d 321:x 315:I 312:E 308:M 301:B 294:A 284:= 279:B 275:/ 271:A 267:t 233:B 230:, 227:A 203:B 199:/ 195:A 168:I 165:E 143:M 117:x 114:d 110:) 104:I 101:E 97:M 92:( 86:B 79:A 69:= 64:B 60:/ 56:A

Index

Mohr
Charles Ezra Greene
moments of inertia
ISBN
978-0-13-257053-4
ISBN
978-0-13-257053-4
Moment-Area Method Beam Deflection
Area-Moment Method. (n.d.)
v
t
e
Structural engineering
History
Duhamel's integral
Modal analysis
Betti's theorem
Castigliano's method
Conjugate beam method
FEM
Flexibility method
Macaulay's method
Moment-area theorem
Stiffness method
Shear and moment diagram
Theorem of three moments
Structural elements
Beam
I-beam
Lintel

Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.

↑