سال انتشار: ۱۳۸۴

محل انتشار: دومین کنفرانس بین المللی بتن و توسعه

تعداد صفحات: ۱۰

نویسنده(ها):

M. R. Adlparvar – School of Railway Engineering, Iran University of Science and Technology (IUST)
H. R. Vosoughifar – Islamic Azad University, Tehran South Unit

چکیده:

Yield line theory was proposed for the first time by Ingerslev [1] in 1923 and substantially pioneered by Johansen[2] 1943. It is essentially an ultimate – load theory for concrete slab design and is based on an assumed collapse mechanism and the plastic properties of underreinforced concrete slabs. The assumed collapse mechanism is defined by a pattern of yield lines, along which the reinforcement has yielded and the location of which depends on the loading and boundary conditions. The result of the yield line method gives an upper bound solution to the collapse load. Ideally,there should be a wide range of collapse mechanisms than the collapse load. The one chosen from this range may not be considered in order to show the mechanism gives the unique solution. Fortunately, in the field of reinforced concrete slabs where most of the yield line work has been carried out, a considerable amount of experimental work has indicated the successful application of upper bound solutions, thus giving confidence to the use of this method in design. The yield line method neglects the effect of strain-hardening of the reinforcement and ignores the effect of membrane forces. The details of the cleat connectors in the column unit are shown in Fig