연속보 주부재의 조밀 및 비조밀 단면 최적화 설계

Optimal Design of Continuous Girders Considering Compact and Non-compact Cross-sections

The LRFD Specification defines two sets of limiting width-to-thickness ratios. On the basis of these limiting values, steel sections we subdivided into three categories: compact, noncompact, and slender sections. A compact section is capable of developing a fully plastic stress distribution (plastic moment), and can sustain rotations approximately three times beyond the yield before the possibility of local buckling arises. Noncompact sections can develop the yield stress before local buckling occurs. They may not, however, resist local buckling at the strain levels required to develop the fully plastic stress distribution. In this paper, 1-Type girders of a 2 span continuous steel bridge are divided into compact and non-compact sections and analyzed. In the design process, an optimization skill was adopted and ADS, a Fortran program for Automated Design Synthesis, was used.