AISC LRFD 1.pdf

Comm. A3.] MATERIAL 169than the anticipated service temperature for the structure. The location of the CVNtest is shown in Figure C-A3.1.The toughness requirements of Section A3.1c are intended only to provide materialof reasonable toughness for ordinary service applications. For unusual applicationsand/or low temperature service, more restrictive requirements and/or toughnessrequirements for other section sizes and thicknesses may be appropriate. To minimizethe potential for fracture, the notch toughness requirements of Section A3.1cmust be used in conjunction with good design and fabrication procedures. Specificrequirements are given in Sections J1.5, J1.6, J2.6, J2.8, and M2.2.For rotary-straightened W-shapes, an area of reduced notch toughness has beendocumented in a limited region of the web immediately adjacent to the flange asillustrated in Figure C-A3.2. Preliminary recommendations have been issued(AISC, 1997) and AISC is currently exploring the associated implications fordesign and construction. It is anticipated that recommendations will be forthcoming,albeit after the publication of this document. For this reason, the reader isencouraged to maintain an awareness of AISC recommendations as they becomeavailable.3. Bolts, Washers, and NutsThe ASTM standard for A307 bolts covers two grades of fasteners. Either grademay be used under the LRFD Specification; however, it should be noted that Gr. BFig. C-A3.1. Location from which Charpy impact specimen shall be taken.Fig. C-A3.2. “k-area.”LRFD Specification for Structural Steel Buildings, December 27, 1999AMERICAN INSTITUTE OF STEEL CONSTRUCTION