Seismic Design, Analysis and Pseudo Dynamic Experiment of SPDs in MRF

• Main Authors: Pu-Yuan Chin, 金步遠
• Other Authors: 蔡克銓
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/7f5f98

碩士 === 國立臺灣大學 === 土木工程學研究所 === 105 === The proposed steel panel damper (SPD) includes three wide-flange sections, the middle inelastic core (IC), and the top and bottom elastic joints (EJs), respectively. Under a severe earthquake, the two EJs in an SPD are designed to remain elastic while the IC could undergo large inelastic shear deformation thereby dissipating seismic energy. In order to delay the buckling of the IC web, stiffeners must be attached to the web, top and bottom ends of the IC. This study investigate the fabrication methods of SPDs, effects of the IC to EJ web thickness or length ratios and the flange thickness on the overall stiffness of the SPD. In addition, three different SPD configurations for the moment resisting frames (SPD-MRFs) and the corresponding capacity design methods of the boundary beams are studied. In order to investigate the performance of the SPDs and SPD-MRF during earthquakes, cyclic and substructure pseudo-dynamic tests are conducted on three full scale SPD specimens. By changing the IC length ratio α, flange thickness, and EJ web thickness, SPD’s elastic stiffness can be adjusted while its shear strength can be maintained by using the same IC depth and web thickness. When the ratio α decreases from 0.6 to 0.2, SPD’s elastic stiffness increases by 20% to 40%, depending on the EJ to IC web thickness ratios. When the SPD flange thickness or the EJ web thickness each increases by 80%, the SPD’s elastic stiffness enhances by 14% to 17% or 13% to 32%, respectively. However, increasing the SPDs’ stiffness have little effect on the lateral stiffness of the SPD-MRF unless the stiffness of the boundary beams are properly stiffened. This study presents three different SPD-MRF configurations and the corresponding capacity design results for three kinds of one-bay 6-story SPD-MRFs. Pushover analyses are conducted on PISA3D models. Using elastic stiffness to steel usage ratio as the criterion, centered-configuration is most effective. The eccentric-configuration is also effective when the eccentricity is one-eighth to one-sixth of the beam span. Besides, single span six floor SPD-MRFs are designed without using capacity design method. Pushover analyses are also conducted on the single-bay 6-story SPD-MRF models with or without the capacity design of boundary beams. Results show that plastic hinges formed at the junctions of SPDs and beams when the beam capacity design is not complied. The plastic hinges formed only at the beam-to-cloumn ends when the beam capacity design is conformed, suggesting the effectiveness of the proposed capacity design procedures. Among the four different SPD fabrication methods introduced, this study adopted the doubler plates to stiffened the EJ webs of two 900mm deep test specimens. Results of the cyclic loading tests using the MATS facility at NCREE confirm that the two specimens have very stable hysteresis performance. The maximum IC shear deformations are greater than 0.09 radian, while the cumulative plastic deformations (CPD) are larger than 300. Although the welds between the top end plate and the flange in one specimen failed due to the large out-of-plane deformation imposed during the test. The EJs of the two specimens remained elastic when the maximum SPD shear developed. The SPD experimental responses are accurately simulated by Abaqus model anslyses. A 600mm deep SPD Specimen was tested using MATS facility and substructure pseudo-dynamic testing procedures with model updating technique. The specimen sustained several SLEs, 9 DBEs, and 1 MCE without any failure. The total CPD is equivalent to 5 times of MCEs, confirming the effectiveness of the proposed SPD-MRF.