huangyhg

does aisc 13th manual still allow 10% negative moment reduct
we usually reduce 10% negative moment in continuous w shape beam in our past design projects, which is allowed per lrfd section a5.1. now our company is going to change to use aisc 13th. i am not sure if it is still allowed to have this 10% reduction in negative moment. i can not find the same section in aisc 13th. is it still allowed to have 10% reduction in aisc 13th.?
thank you for your clarifications on this issue.
since i graduated after the 13th edition came out, i am unfamiliar with any other version.
would you be referring to plastic design?
if so, appendix 1 would be applicable.
note that your sections must be compact to take advantage of plastic design.
yes - appendix 1: inelastic analysis and design: section 1.3 "moment redistribution"
the allowed 10% reduction comes from section f1.1 (pg 5-45) of asd 9th edition. the moment design methodology is completely changed and is covered in chapter f in the 13th edition. member design is based on plastic analysis with checks required for lateral torsional buckling and other provisions depending on the type of section being used. i don't see anywhere where the 10% reduction is allowed. in section f1, at the bottom of page 16.1-46, there is a statement that available flexural strength >= maximum required moment causing compression in the flange being considered.

__________________
借用达朗贝尔的名言：前进吧，你会得到信心!
[url="http://www.dimcax.com"]几何尺寸与公差标准[/url]