The Chart Method of Multi-Columns Effective Length with Difference Axial Force

Abstract

In practical engineering, multi-columns stability calculation is very common and very important. Determining the multi-columns effective length is the most important in stability calculation. So there are some nomo-graphs and formulas in Chinese Code for design of steel structures .The structures are very varied and calculation is too difficult. The nomo-graph and formulas in chinese standards are not fully applicable to a variety of situations. For example, in the multi-frame, the axial force is large difference between stories. If we determine the effective length with the nomo-graph and formulas in chinese standards, it will be unsafe in sometimes. This paper gives some nomo-graphs and formulas to determined the effective length. According to the method, we can determined the effective length quickly, and visually see the trend in the curves of effective length when the parameters change. The nomo-graph and formulas in this can be said to be a supplement to the chinese standards.