The North American standard for the design of lateral systems constructed of cold -formed steel (CFS) (AISI S), which is published by the American Iron and. The American Iron and Steel Institute Committee on Framing Standards has developed AISI S, the North American Standard for Cold-Formed Steel Framing. It has been accepted for inclusion in AISI-Specifications for the The American Iron and Steel Institute (AISI) Committee on Framing Standards (COFS) has.
|Published (Last):||3 July 2009|
|PDF File Size:||14.27 Mb|
|ePub File Size:||1.89 Mb|
|Price:||Free* [*Free Regsitration Required]|
C2 Type I Shear Walls A shear wall assembly using an approved adhesive to attach shear wall sheathing aisi s213 the framing is not yet recognized by this standard aisi s213 by ASCE 7. When seismic response modification coefficient, R, is taken greater than 3, the uplift anchorage and boundary chords shall also comply with the requirements of Section C5.
Changes made in Supplement No. The width of a wall pier w shall be defined as the sheathed width of the pier adjacent to the opening. The version of Aisi s213 S includes requirements for the brace material and the use of capacity design principles; as well, the engineer is directed towards using welded connections to avoid possible net section fracture of the braces.
The height of a wall pier h shall be defined as the height of the opening adjacent to the sheathed wall. Standard Costing and Variance Analysis costing techniques. Provisions shall be made for pretensioning, or other methods of installing tension-only diagonal strap aisi s213 shall be used to guard against loose diagonal straps. Specific references to this research are cited in this Commentary. Note that it is never permitted to choose an R of 3 for systems with a aisi s213 assigned R.
aisi s213 Foundations shall be designed to resist the loads resulting from the lesser of the loads that the system can deliver C5. However, the shear modulus may be approximated from the through thickness shear rigidity Gvtvthe nominal panel thickness t and through thickness panel grade and construction adjustment factor CG provided in the AFPA Manual AFPA, It should be noted that Section RdRo is taken greater than 2 for sheathed shear walls, and greater than 1.
Eccentricity shall be considered in the design where single-sided diagonal strap bracing is provided. Nominal strengths Rn in Tables C2. Infindings of a research project at McGill University on the inelastic performance of welded Comeau and Zisi, and screw connected Velchev and Rogers, strap braced walls demonstrated that the Rd, Ro and height limits values listed in Section A4.
The nominal aisi s213 values for shear walls faced with fiberboard in Table C2. When RdRo is taken greater aisi s213 2 for wood sheathed shear walls, the uplift anchorage and boundary chords s23 also comply with the requirements of Section C5.
SS Standard and Commentary (Reaffirmed )_e – PDF Free Download
These nominal strength values were found to be within 90 percent of the nominal strength values for similarly sheathed wood framed walls. Nevertheless, to develop a desirable response, AISI S requires that connections for boundary members and collectors transferring load to and from the shear wall be capable of developing the nominal strength of the aisi s213 wall or the expected over-strength of the shear wall. Generally, the protocol frequency ranged between 0.
Refer to the discussion in Commentary Section C1. Preliminary dynamic analyses of representative cold-formed steel framed buildings designed with the proposed R-values have shown that the inelastic shear deformations are within an acceptable range, as defined aisi s213 test results Blais, It is intended aisi s213 where such elements are present in combination with a cold-formed steel framed system, the cold-formed steel framed system needs to be designed to aisi s213 for the seismic forces generated by the additional mass of such elements.
If the load combinations for Allowable Stress Design ASD with the system overstrength factor are desired to be used and they are to be checked against the member nominal strength, then member nominal aisi s213 is required to be divided by aisi s213. Type I shear walls sheathed with wood structural or sheet steel panels are permitted to have openings, between hold-down anchors at each end of a aisi s213 segment, where details are provided to account for force transfer around openings.
The nominal aisi s213 nominal resistance shall be based upon a panel edge screw spacing that is greater than or equal to 4 inches mm o. Seismic Force Resisting System. An extensive aksi program of single-story laterally loaded shear walls constructed of Aisi s213 products was first carried out Branston et al.
Screws in the field of the panel shall be installed 12 inches mm o. Since the shear wall tests used as the basis of AISI S were carried out over a short time span, the tabulated values are for short-term duration loads i. Matthew Bible Commentary Biblical.
Aisi s213 Framing and Anchorage In diaphragms, shear walls and other braced walls; the basic lateral resisting aisi s213 is the attached sheathing or brace. Steel sheets shall be permitted to be applied either parallel to or perpendicular to framing.
For diagonal strap braced walls, a designer has the option to choose an Asi of 1. In the Commentary, aisi s213, equations, figures, aisi s213 tables are identified by the same notation as used in the standard. New values were added for designation thickness for stud, track and blocking equal to 33 mils min. Where wood aisi s213 panel or steel sheet qisi shear walls aisi s213 used to provide aisi s213 to seismic forces contributed by masonry and concrete walls, deflections are limited to 0.
Only the most common structural systems are identified and have assigned values of Rd and Ro in Table A Method for designing a seismic force resisting system in which a specific elements or mechanisms are designed to dissipate energy; b all other elements are sufficiently strong for this energy dissipation to be achieved; c structural integrity is maintained; d elements and connections in the horizontal and vertical aisi s213 paths are designed to resist these s231 loads and corresponding principal and companion loads as defined by the NBCC; e diaphragms and collector elements are capable of transmitting the aisi s213 developed at each level to the vertical seismic force resisting system; and f these loads are transmitted to the foundation.
S213-07-S1-09 Standard and Commentary (Reaffirmed 2012)_e
Use of the fifth percentile approach to determine nominal aisi s213 strengths resulted in an average ASD factor of safety of 2. This is consistent with the way tabulated systems were tested and is deemed necessary for the performance of the system. The proposed R-values should only be used in the case of aisi s213 sheathing connection aisi s213 mode in the shear wall, as opposed to chord stud failure.
Specific references are included in this Commentary.