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Chapter 6. Design of Axially Loaded Compression Members. Design. Selection of: Single shapes. Process (trial-and-error): Column size assumed r is found Design stress calculated Compare to required strength Try larger or smaller section as necessary.
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Chapter 6 Design of Axially Loaded Compression Members
Design • Selection of: • Single shapes • Process (trial-and-error): • Column size assumed • r is found • Design stress calculated • Compare to required strength • Try larger or smaller section as necessary • Process (use of AISCM column’s tables): • Table 4-1, page 4-12 to 4-204 AISCM 14th Ed. • Table 4-1, pages 417-607 (4-10 to 4-200) • KL • Try a section • Check section
AISCM Column tables • For W and WT sections the steel strength Fy = 50 ksi is usually used • (KL/r)y is usually > (kl/r)x • (KL)y is used to enter column tables • HSS sections in Table 4-5 • Steel Pipe sections in Table 4-6 • Std pipes = standard pipes • XS = extra strong pipe • XXS = double extra-strong pipe
Column Splices • In multistory buildings • Placed 4 feet above finished floor • Transfer some of the compression load • Typical column splices are found in Table 14-3 (AISCM page 14-22 to page 14-43) • General requirements given in section J1.4 of AISCM • Typical column splices Figure 6.2 • For equal or different nominalcolumn’s depth.
Amount of load to carried by splice plates • Difficult to estimate • 100% for not miled surface plates • 25 to 50 % when mild surface and only axial loads • 50 to 75 % when bending is involved
Single-Angle Compression Members • Concentric Loading • AISCS E5 • Table 4-11 of AISCM • Based on • For equal leg angles and for unequal leg angles connected through their longer legs: