I checked the natural frequency with and without the mass of the supported pipes and the difference was not significant. I'll take a look at the AASHTO. Thank you for the suggestions!
Can anyone provide guidance on a minimum natural frequency, or a range of natural frequencies to avoid, when designing a relatively long-span steel box truss? I'm designing a two-span box truss supported on trussed towers with truss spans of 118 feet. The trusses are supporting process piping...