الفهرس | Only 14 pages are availabe for public view |
Abstract In this thesis the optimum design of panelled beams roofs is studied. A finite element computer program simulating the elastic behavior of roofs made up of thin plates and panelled beams was prepared. The program employs an eight node five degrees of freedom quadrilateral element formed from a plate bending element imposed on a plane stress element. A modification in the program was made to incorporate a two node beam element which axis is displaced a distance ez from the plane of the analyzed plate. such modelling allows simulating the actual stiffness of the grid roof and results the inplane forces that develops in slabs as a result of T- section behavior of beams. The investigated model was a roof composed of one or more square equal panels (1,4,6 and 9 panels) . Each panel is 15.0 x15.0 ms. The variable were the number of inner beams in each panel, and whether girders were employed between panels or not. All the selected models had a slab thickness of 10cm and the roof beams’ were designed to satisfy both strength and deflection requirements according to Egyptian code of 1989. This research has resulted the optimum arrangement of panelled beams that resul tes the minimum direct cost, whether the panels are separated by girders or not. The cost was estimated assuming a relative cost ratio between the cost of a square meter of timber shuttering to that of one cubic meter of casted concrete to the cost of one ton of fabricated reinforcing steel. |