6.2 Analysis and design of columns (N compression) ·Basic assumptions same as that in pure bending Conditions of compatibility same as that in pure bending Equilibrium equation T+C=T+N M=CZ+T(ho-a)-N(e+h/2-as) The equivalent rectangular block same as that in pure bending6.2 Analysis and design of columns （N compression) • Basic assumptions same as that in pure bending • Conditions of compatibility same as that in pure bending • Equilibrium equation ( ) ( / 2 ) ' 0 ' ' M CZ T h a N e h as T C T N          • The equivalent rectangular block same as that in pure bending