Handbook of Civil Engineering Calculations

Mx = 200 kip-ft (271 kNm); My = O; single-curvature bending (i.e. equal and opposite end
moments); and no transverse loads along the member. The floor-to-floor height is 15 ft
(4.57 m).

Calculation Procedure:

1. Find the effective axial load for the beam-column
   This procedure considers singly and doubly symmetric beam-columns: members subject-
   ed combined axial compression and bending about one or both principal axes. The combi-
   nation of compression with flexure may result from (either)

(a) A compressive force that is eccentric with respect to the centroidal axis of the

column, as in Fig. 42a

(b) A column subjected to lateral force or moment, as in Fig. 42b

(c) A beam transmitting wind or other axial forces, as in Fig. 42c

Interaction Formulas:
The cross sections of beam-columns must comply with formula (Hl-Id) or (Hl-Ib) 9
whichever is applicable.
For (P 11 AkP 11 ) ^ 0.2

Pu » / M/x Muv \

—

u

— + £. / ^L- +

u

^- \ < i o (Hl-Ia)

^ 0 Pn 9 \<M4c ^AfJ ^ }

FOT (P^ 0 P 11 ) < 0.2

PU ( M11x Muv \

^r

+

hr^r

+

-^r) -

L0 (H1

'

lb)

2(J) 0 Pn \ QbMnx QbMny /

For beam-columns:

Mcc> M^ = required flexural strengths (based on the factored loads) including

second-order effects, kip-in or kip-ft

FIGURE 42. Combined compression and flexure.