2012/11/22 DValue methods the shear force of the k column in-t floor texural stitness for beam and column e the position of the point f contra-dexure in columr M。= ) 。-形h-的 5.12 M-Curve Three Principles of seismic design Lesson from this Diagran strong shear-weak fexure D Lesson from this Curve Lesson from these picture M-eCu 62012/11/22 6  the shear force of the k-th column in i-th floor where Vik is the horizontal shear force induced in column k on i th story; Dik is relative shear stiffness of column k on i th story; n i k ik ik ik V D D V   1 (5.7)  n k Dik 1 is summation of relative shear stiffness of total columns on i th story. D Value methods 2 c h 12i D  Determine the internal forces of lateral-force-resisting frames :  Determine flexural stiffness for beam and column;  Calculate D value;  Determine shear force for each column;  Determine the position of the point of contra-flexure in column;  Calculate column moments, then derive the beam moments based on equilibrium of beam to column joint, and distribution of beam stiffness / M kl  Vik h (5.11) ( ) / M V h h ku  ik  (5.12) 6.4 Seismic design of RC frames 6.4.1 Principle of seismic design Three Principles of seismic design strong shear - weak flexure strong column - weak beam strong joints - weak members M-φ Curve  Lesson from this Diagram M-φ Curve of a beam  Lesson from this Curve Ductility and compress ratio  Lesson from these picture