good day, i tried designing a simply supported steel beam on staad pro using the same loading but i tried different Dmax
UB 533X210X138 = Utilization ratio= 0.9852117
UB 457X191X161 = Utilization ratio = 0.75
isn't the lower steel section supposed to have the higher ratio?
This can be very much possible. Result of a section does not only depend on its depth value. It also depends on section modulas, radius of gyration, cross sectional area etc. If you notice, for the section with lower depth, weight is more than the other. Which suggests, cross section area is higher. Also, you will find moment capacity is higher. Hence, the higher depth is giving higher ratio here.
Answer Verified By: hakeem olokunola
if i do not apply the Dmax parameter it would select a steel 762X267x134 and a ratio of 0.77. is there any way i can tell staad to pick smaller sections?