b'YOUR TOOLKIT FOR BUILDING EXCELLENCEare not controlling the design.Posts withfor knee braces in Building 5.Increasing knee braces in Building 4 failed by up to 38%the quantity of nails to resist the required while posts in the same building but withoutload will diminish the difference between knee braces passed by 0.94 stress unity.the slip and no slip designs in Building 5.Slippage: The effects of fastener slippage at knee braceBefore considering knee bracing, it is recommended that connectionsarerelativelyinsignificant.the building designer first check if they are beneficial when Buildings with knee braces with slippagediaphragm action is included in the design. Certain building performedwithinafewpercentofthesizes may not benefit from knee braces when diaphragm buildings with knee braces without slippage.action is included in the design. For example, a full-scale The only difference observed was in Building(40x80x16 to the eave height) post-frame building test 5 (80-foot truss span), a difference of 23% inshowed that horizontal eave deflection dropped from 6.1 knee brace axial compression forces.The slipwhen metal cladding was not put in place (frame only) to 0.44 modulus in all the buildings was based on (6)when metal cladding was put in place (Gebremedhin, 1991).0.148x3 nails.This would not be enough Table 4:Results of structural analysisBuilding ID Number Building Size Knee Brace (KB)condition Effective Shear Modulusof Roofing/SidingNumber of Bays Diaphragm HorizontalShear Stiffness Endwall Stiffness Interior Frame Stiffness Eave Load Restraining Force atMax Deflection Max. HorizontalDisplacement at Eave Deflection at EndwallsShear Load at Endwalls Max. Internal HorizontalDiaphragm Load G eff C h k e k R Q max e V e V max,d(ft) (lb/in) (lb/in) (lb/in) (lb/in) (lb) (lb) (in) (in) (lb) (lb)No KB 58 693 576 2.03 0.83 2996 26501 40x80 KB no slip 1260 10 6112 3615 306 1002 453 1.79 0.77 2770 2269KB w/ slip 278 968 464 1.81 0.77 2784 2300No KB 58 693 621 1.26 0.53 3173 28272 40x80 KB no slip 2210 10 10720 5990 306 1002 602 1.31 0.56 3380 2879KB w/ slip 278 968 605 1.31 0.56 3361 2877No KB 58 693 665 0.49 0.21 3353 30063 40x80 KB no slip 6200 10 30074 15965 306 1002 815 0.61 0.27 4249 3748KB w/ slip 278 968 801 0.60 0.26 4160 3676No KB 58 693 643 0.87 0.36 3262 29164 60x80 KB no slip 2210 10 16080 8980 307 1003 700 0.99 0.42 3784 3283KB w/ slip 279 968 696 0.98 0.42 3735 3251No KB 182 712 443 1.48 0.37 5089 47335 80x160 KB no slip 2210 20 21440 13907 862 985 201 0.91 0.26 3650 3157KB w/ slip 680 913 238 0.99 0.28 3846 3389Building ID Number Building Size Knee Brace (KB)condition Effective Shear Modulus ofRoofing/SidingMax. Axial CompressionLoad in Knee Brace Max. Axial Tension Loadin Knee Brace Max. Shear at Grade inWindward Post Max. Moment at Grade inWindward Post Max. Shear at Grade inLeeward Post Max. Moment Grade inLeeward Post Stress Unity for WindwardPost Below Grade Stress Unity for WindwardPost Above Grade Stress Unity for LeewardPost Below Grade Stress Unity for LeewardPost Above GradeG eff P k,comp P k,ten V G,Wind M G,Wind V G,Leew M G,Leew(ft) (lb/in) (lb) (lb) (lb) (lb-ft) (lb) (lb-ft)No KB - - 814 2705 698 2443 0.95 0.93 0.85 0.831 40x80 KB no slip 1260 1231 549 780 2488 741 2538 0.88 0.81 0.89 0.84KB w/ slip 1105 498 785 2510 737 2529 0.89 0.82 0.89 0.83No KB N/A N/A 792 2351 676 2085 0.84 0.81 0.74 0.722 40x80 KB no slip 2210 976 212 706 2019 666 2065 0.73 0.68 0.74 0.71KB w/ slip 869 186 715 2054 667 2066 0.74 0.67 0.74 0.70No KB - - 770 1995 653 1721 0.73 0.69 0.64 0.613 40x80 KB no slip 6200 1271 610 660 1346 559 1424 0.51 0.68 0.53 0.68KB w/ slip 1139 551 618 1412 568 1420 0.53 0.61 0.53 0.61No KB - - 781 2171 665 1918 0.79 0.94 0.69 0.884 60x80 KB no slip 2210 1602 272 643 1648 648 2114 0.63 1.38 0.78 1.38KB w/ slip 1432 248 657 1702 642 2044 0.63 1.24 0.76 1.24No KB - - 874 3660 764 3493 0.51 0.48 0.48 0.465 80x160 KB no slip 2210 3474 864 864 2997 1062 4088 0.48 0.98 0.6 0.98KB w/ slip 2660 750 879 3145 948 3732 0.45 0.74 0.55 0.74continued on page 22 FRAME BUILDER - MAY2023 / 21'