1977x
003335
2020-01-23

Question

I am comparing the flexural buckling design according to the equivalent member method and the internal forces according to the linear static analysis with the stress calculation according to the second-order analysis, including imperfections. The differences are very large. What could be the reason for this?


Answer:
While the influence of imperfection increases significantly with increasing axial force and the ratio increases exponentially in the case of the second-order analysis, the influence of imperfection only increases linearly in relation to the axial force in the case of equivalent member design. Therefore, there is usually a greater difference between the design ratios according to the linear static analysis using the equivalent member method and the second-order analysis using the stress analysis for the structural systems with a very high or very low design ratio.