Experimental Investigation on Retrofit of Steel Gable Frames Using Local Post- Tensioning
Dissertation
Harb Hadi Shallal AL-Zubeidi
Civil Engineering
1401
53p.
cd
M.S.
structural engineering
1401/06/16
In this research, the effect of using post-tensioned and post-compressed bars on the retrofitting of the steel gable frames were studied. In order to investigate the possibility of strengthening a steel beam using post-compression bars, the behavior of three samples, a simple beam, a post-tensioned beam using a post-tensioned bar, and a post-compressed beam using a post-compression bar were determined experimentally in the laboratory. This test showed the possibility and effectiveness of the post-compression technique in retrofitting the steel beams. Investigations showed that adding a post-tensioned steel bar with a diameter of 16 mm and a length of 1.0 m to a beam with IPE 140 section increases its capacity from 3250 kg to 6340 kg. Also, adding a post-compressed steel pipe of 5 cm diameter, 4 mm thickness, and 1 m length increases its capacity to 6670 kg, that is, an increase of 95% in the case of post-tensioning and 105% in the case of post-compression. The post-compression technique does not increase the magnitude of axial forces that leads to the beam torsional buckling. In order to accurately assess the generated internal forces and the behavior of the beams, finite element models for three studied beams were built in SAP2000 software. Investigations showed the effectiveness of post-compression and post-tension in the retrofitting of the beam. In the continuation of the research, the behavior of a reinforced and unreinforced steel gable frame was investigated using post-tensioned and post-compressed bars using SAP2000 software. It was shown that the use of the post-compression and post-tensioning technique in the members simultaneously, has greatly affected the bearing capacity of the gable frame. The demand to capacity ratio for critical beam in the post-tensioned gable frame decreased from 0.926 to 0.627 in the post-compressed gable frame, as well as the axial compression force reduced from 62,482 to 2,602 kg for the same beam in the gable frame.
بررسی تجربی مقاوم سازی قاب های شیب دار فولادی با استفاده از پس تنیدگی موضعی
Retrofit of Gable Frame, Local Post-Tensioning, Steel Gable Frame, Experimental Study, Finite Element Model.
مقاوم¬سازی قاب¬های شیب¬دار فولادی، پس¬کشیدگی موضعی، پس فشردگی، قاب شیب دار فولادی، مطالعه آزمایشگاهی، مدل اجزای محدود