PREPARATION OF UNlXAIAL CIIART FOR RECTANGULAR CONCRETEFILLED STEEL COLUMNS BASED ON RIGID PLASTIC PRINCIPLES
Abstract
Composite columns are in an int:reOled u.roge for constnlcrioo 0/ high-risl! and medium-rise buildings, bridges and othf!r J(ructureJ. However,
their design procedure as proprued by the relevant Ethiopian Building Code Standard, whIch is also a derivaliVf! of the corresponding European Standard Eurocode 4, calls for e:ctemive numerical effort for dmwing the moment axial{ orce interaction charlJ. Furthermore, the
results obtamed following those procedures are based ,QPI" curve-firtmg techniques making IUf! of Widely sparse control poinlS and, consequently, they produce approximate results. This paper explores the shortcomings· of the relevant local building code standord for the deJign proceJJ and pre!Senls improved dellgn chort proceduru for
com:rete-:filled rectangular steel rube columns. The proposed pTYX"edure simplifies the deSign process and, at tlu same tIme, conslder(Jbly mcreases the accur(J<), of results. A unifieri approach has been presented for the procedurl! of establIshing mteractlOn design charts for concrete-:filled steel tubes (CFTs) under Wlia:cial bending and mil/able charts have been preparedfor most .frequently encountered shapes m practice - rectanglliar and square shapu. The proposed procedure may also be Jeveloped and adapted to facr/,tate the preparation of SImilar design charts for other shapes and malenal types. Final~v, numerical examples will be presented 10 dl!monstrate implementation of the proposed procedure and to provide m.1ight into comparative quality of the charts with th().fe generDted
accordmg to the relevant national code standard