隅撐構架為一兼顧勁度與韌性之有效結構設計，惟當隅撐構件挫屈後，桿件將因累積塑性變形達其極限，而有斷裂，結構承載性能因之而有甚大減損，為進一步提升結構耐震效能，本研究結合自復位梁柱接頭及高延展隅撐構件，形成高延展隅撐鋼結構，並將之應用於多層結構設計。研究中藉一系列配置不同高延展隅撐組合之構架反覆載重試驗，評估其強度、變形及能量消散能力，以界定其在耐震設計之應用性。研究結果顯示，在梁柱構件保持完整及適當之樓層隅撐強度比(本研究中為下層與上層隅撐強度比值小於1.431)，增加下層隅撐強度可獲致較均勻之樓層位移比。另由試驗結果比較得知，配置高延展隅撐之雙層單跨構架強度可達相同梁柱尺寸抗彎構架強度之2.32至2.57倍，能量消散則為抗彎構架之4.15至4.82倍；配置高延展隅撐之雙層雙跨構架強度可達相同梁柱尺寸抗彎構架強度之1.78至2.05倍，能量消散則為抗彎構架之2.31至2.95倍，此顯示高延展隅撐在多層鋼結構之耐震設計上，具有相當之可行性。;Knee braced moment resisting frames (KBRF) possess adequate stiffness and ductility, thus are suitable structural forms for earthquake-resistant designs. The performance of KBRF greatly depends on the integrity of the knee braces. When knee braced members buckle under compression, the members may suffer from fracture if the plastic deformation capability is insufficient. This study is focused on the further improvement of multi-story KBRF by adopting high-ductility knee braced members with various brace strength combinations. A series of cyclic loading tests were conducted on the moment resisting frame (MRF) and KBRFs to evaluate the effectiveness of high-ductility knee brace design on the multi-story steel frame constructions. Test results show that the strength of two-story one-bay KBRFs with high-ductility knee braces is 2.32 to 2.57 times of the same-sized MRF, and the energy dissipation is also increased by 4.15 to 4.82 times. The strength of two-story two-bay KBRFs with high-ductility knee braces is 1.78 to 2.05 times of the same-sized MRF, and the energy dissipation is also increased by 2.31 to 2.95 times. It is also found from the comparisons that the improvement in frame performance is higher when the brace strength ratio between the lower and upper stories is higher, provided that the integrity of the beams is sustained. Overall evaluation on the strength, deformation capacity and energy dissipation of the KBRFs validated the effectiveness of the high-ductility knee brace design in the engineering applications.
