▁used ▁as ▁the ▁design ▁strength ▁of ▁the ▁section . ▁ ▁Several ▁situations ▁may ▁exist ▁where ▁a ▁rational ▁analysis ▁application ▁of ▁D SM ▁can ▁be ▁used . ▁In ▁general ▁these ▁would ▁include : ▁( 1 ) ▁determ ining ▁the ▁el astic ▁bu ck ling ▁values ▁and ▁( 2 ) ▁using ▁the ▁D SM ▁equations ▁in ▁Append ix ▁ 1 ▁to ▁determine ▁nom inal ▁flex ural ▁and ▁ax ial ▁capac ities , ▁M n ▁and ▁P n . ▁The ▁prem ise ▁of ▁D SM ▁itself ▁is ▁an ▁example ▁of ▁rational ▁analysis . ▁It ▁uses ▁el astic ▁bu ck ling ▁results ▁to ▁determine ▁the ▁ult imate ▁strength ▁through ▁the ▁use ▁of ▁empir ical ▁strength ▁curves . ▁This ▁provides ▁design ers ▁with ▁a ▁method ▁for ▁performing ▁a ▁rational ▁analysis ▁in ▁a ▁number ▁of ▁unique ▁situations . ▁ ▁In ▁some ▁cases ▁the ▁rational ▁analysis ▁extension ▁to ▁D SM ▁may ▁be ▁as ▁simple ▁as ▁dealing ▁with ▁an ▁observed ▁bu ck ling ▁mode ▁that ▁is ▁difficult ▁to ▁identify ▁and ▁making ▁a ▁judgment ▁call ▁as ▁to ▁how ▁to ▁categor ize ▁the ▁mode . ▁But ▁it ▁could ▁also ▁be ▁used ▁to ▁allow ▁an ▁engineer ▁to ▁include ▁the ▁effects ▁of ▁moment ▁grad ients , ▁the ▁influence ▁of ▁different ▁end ▁conditions , ▁or ▁the ▁influence ▁of ▁t ors ion ▁war ping ▁on ▁all ▁bu ck ling ▁modes . ▁ ▁There ▁are ▁currently ▁no ▁prov isions ▁within ▁the ▁D SM ▁that ▁per tain ▁to ▁she ar , ▁web ▁cri pp ling , ▁holes ▁in ▁members , ▁or ▁strength ▁increases ▁due ▁to ▁the ▁cold ▁work ▁of