Portal Frame Analysis

2782 WordsApr 16, 201112 Pages
University of Manchester University of Manchester NISHANT AGARWAL The report primarily discusses results obtained from the conducted experiments and includes computed data from the Kingston computer program. The value of the plastic moment capacity of each experiment was obtained; Obtained value was used to find the yield strength of the structures and compare them to typical values for mild steel. The important data is summarized in a table; followed by a list of important formulae. All individual results are listed in the appendix at the end. NISHANT AGARWAL The report primarily discusses results obtained from the conducted experiments and includes computed data from the Kingston computer program. The value of the…show more content…
The computed value fy of 394.1 N/mm2, is within the required range of yield strength for mild steel, i.e. (360 – 430 N/mm2). NOTE: Before commencing the experiment, the cantilever strip was bent at about 20mm off its edge to prevent the weight hanger from slipping off. The hanger was then loaded and deflections measured till collapse of the cantilever arm. 2.2 Beam Mechanism: Fig. 2.2(b) Plastic hinge formation, Beam mechanism Fig. 2.2(b) Plastic hinge formation, Beam mechanism Fig. 2.2(a) Portal Frame with Vertical Load Fig. 2.2(a) Portal Frame with Vertical Load From Plastic analysis, Mp = 10.35 kN-mm (Beam Mechanism) Mp = 10.35 kN-mm (Beam Mechanism) Wl2θ = MP θ+ MP 2θ + MP θ → MP= Wl8 Notes & Comments: Number of plastic hinges that should form are 4; Albeit, Moments at B, C, and D are greater than those at fixed feet, and a beam mechanism forms in BCD. Therefore, only 3 plastic hinges are formed. (Todd, 2000) NOTE- The behavior is similar to a fixed ended beam. Fig. (II.A) shows the formed plastic hinges on the collapsed portal frame due to vertical loading at l2. Plastic hinges have been labeled in order of appearance. The formula for moment capacity of the above mechanism has been calculated by the virtual work method. The computed value fy of 356.589 N/mm2, is within the required range of yield strength for mild steel, i.e. (360 – 430 N/mm2). Fig. (II.B) shows the
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