Column, beam and brace members of frames, that resists moderate ductility level loads are automatically controlled and reported according to Table D1.1.


Fy = Specified minimum yield stress
Ry = Ratio of the expected yield stress to the specified minimum yield stress, Fy
λhd= Limiting slenderness parameter for highly ductile compression elements
λmd = Limiting slenderness parameter for moderately ductile compression elements
E= Modulus of elasticity of steel = 29,000 ksi (200 000 MPa)

Table D1.1 Limiting Width-to-Thickness Ratios for Compression Elements for Moderately Ductile and Highly Ductile Members

  • In order for horizontal load-bearing system elements to perform sufficient plastic deformation under earthquake effects without local buckling, the width-to-thickness ratios of compression elements must meet the conditions given in Table D1.1.

  • The width-to-thickness ratios of steel elements are automatically controlled and reported with steel elements reports according to Table D1.1.