Steel Frame Design - ladbs

member for a minimum shear strength equals to 50% of the nominal strength of theadjacent element. Not less than two stitches shall be use and shall be equally spaced aboutthe member centerline. AISC I-14.2e ~ (welded stitches are recommended)~ 6. Design the bracing connection (including beam-to-column connection if part of thebracing system) for the least of the following:9 a) minimum nominal axial tensile strength of the bracing member, R y F y A g ;9 b) the force in the brace that results from the Load Combinations of AISC I-4.1; or9 c) the maximum force, indicated by analysis, that can be transferred to the brace by thesystem. (AISC I-14.3.a ~)~ 7. Verify that the minimum tensile strength of the bracing member, k t P n , is the least valueobtained according to the limit states of yielding as follows:9 a) for gross section yielding: 0.9F y A g9 b) for fracture in the net section: 0.75F u A e . (AISC I-14.3b ~)~ 8. Address the design flexural strength of the bracing connection in the direction the bracewill buckle. The minimum desired strength shall be equal to or greater than the expectednominal flexural strength of the brace 1.1R y M p about critical buckling axis of the brace(see exceptions). AISC I-14.3c ~9 9. The design of gusset plate of the bracing connection shall include consideration ofbuckling. AISC I-14.3.d ~~ 10. In a V-type and inverted V-type bracing, a beam that is intersected by braces shall bedesigned to meet the following:9 a) support the effects of all tributary dead and live loads from LRFD Load CombinationsA4-1, A4-2 and A4-3 assuming that the bracing is not present;9 b) resist the effects of LRFD Load Combinations A4-5 and A4-6 except that load Q bshall be substituted for the term E.9 c) the top and bottom flanges at the point of intersection of braces are able to support alateral force that is equal to 0.2F y b f t bf . AISC I-14.4a ~~ 11. OCBF in roof Structures and in buildings two stories or less in height may be designedwithout the requirements listed above (items 1 thru 6) and the requirements of AISC-I.14.4, provided that the member and connection strength is determined by the loadcombinations as required in AISC I-4.1 ~~ 12. Use R value of 5.6 for the base shear determination. Table 16-N ~F. ECCENTRICALLY BRACED FRAMES (EBF)~ 1. Link members shall comply with the width to thickness ratio per AISC Table I-9-1 ~~ 2. The minimum yield strength of the Link member shall not exceed 50 ksi. AISC I-15.2b ~~ 3. The required shear strength of Link members V u shall not exceed kV n . AISC I-15.2d ~~ 4. If the required axial strength P u in a Link member exceeds 0.15P y (0.15F y A g ), theLADBS-Corr.Lst.44 (5/2001)6 of 9www.ladbs.org