7 Members in Compression

The analysis of column buckling in the creep range is an extremely complicated subject. Different methods of analysis have been proposed and are available to the designer. Each of these methods has its advantages and disadvantages regarding accuracy of results and complexity of solution. The methods presented in this chapter are relatively simple to perform but fairly conservative. Designers must exercise their judgment and use their experience in using the various equations presented in this chapter.

Background equations for the design of axially loaded members operating at temperatures below the creep range are presented in Section 7.2.1. These equations are then used as basis for developing buckling equations for axially loaded members operating at temperatures above the creep range as discussed in Section 7.2.2. The creep buckling phenomenon of columns can be thought of in terms of the column creeping under a sustained load up to a deformation level where regular buckling occurs. Accordingly, a time factor must be included in the buckling equations as discussed below.