ABSTRACT
Glossary... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31-53
References .. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31-53
Further Reading ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31-57
The concept of the effective length factor has been well established and widely used by practicing
engineers and plays an important role in compression member and column design. The essence of
the concept is to estimate the interaction effects of the whole frame on an individual compression
member. In the development of design interaction equations for beam-columns, much discussion
has been focused on the need and validity of using the effective length factor K in the equations
(Cheong-Siat-Moy 1986; Liew et al. 1991; ASCE 1997; White and Clarke 1997a,b; Schmidt 1999).
Although attempts were made to formulate the general interaction equations without K factors, it
was found that this was almost impossible if the interaction equations were to be versatile enough
for a wide range of slenderness ratios and load combinations (Liew et al. 1991). It is well known that
the effective length factor approach introduces inaccuracies into the design process; the simplicity of
the approach, however, is likely to still make the approach an important part of compression
member design in the foreseeable future (Hellesland and Bjorhovde 1996). The most structural
design codes, standards, and specifications worldwide have provisions concerning the effective length
factor.
