矩形コンクリート充填鋼管部材の曲げ耐力•変形性能の算定法

摘要

Concrete filled steel tube (CFT) members with square section can be expected to have higher strength than CFT members with circular section of the diameter of the same size with the width of the square section. However, evaluation method of bending capacity and ductility of CFT members with square section has not been established in the design standard. Therefore, to figure out mechanical properties of CFT members with square section, we carried out cyclic loading tests, focusing on width-thickness ratio, shear-span ratio, axial force ratio and material strength. As a result, we have proposed an evaluation method of bending capacity and ductility in case of applying the yield load and the maximum load.%本研究では，矩形(正方形断面)CFT部材の曲げ耐力や変形性能の定量的な算定法の提案を目的として，正負交番載荷試験を行い，その破壊性状の確認と，曲げ耐力や変形性能の算定法の検討を行った。以下に，本検討において得られた結論を記す。(1)圧縮軸力を受ける矩形CFT部材の破壊性状は，鋼管の降伏以降，最大荷重に到達する直前で鋼管基部に局部座屈が生じ，最大荷重に到達する。載荷が進むにつれて局部座屈が進展し，緩やかに荷重が低下する。最終的には，鋼管角部でき裂が生じる。