COMPUTER AIDED ANALYSIS AND DESIGN OF SLABS BY YIELD-LINE METHOD

Abstract

There are several theor i e-3e and just one theory but pride of place, really deserved to be called as "engineer's tool" for analysis of slabs i. e. Yield Line Theory. It's versatility owes for analysis of all sorts of shapes of slabs; which probably may not be handled by elastic analysis. The only requirement being that the engineer should i ntuti ve:l y be able to picture the likely mechanism of collapse; which of course may be many in numbers. The correct mode is one for which the collapse load is minimum. To analyse the slab for each expected pattern manually rather seems to be extremely tedious. To overcome this complexity and to meet the modern chat lerges of present "computer 's revolutionary design" a generalized computer program GY L-- () is being attempted in this thesis. This program GYL-9O can analyse any regular and polygonal slabs subjected to any combination of loading and boundary conditions . The program is based on both equilibrium as well as virtual work methods. If the trial yield line pattern is correct then the calculated m/p Cultimate moment to collapse load ratio) values by both the methods should match. If this is not it indicates there is error in selection of trial pattern. To minimize this error and automatically leading towards the improved trial pattern the non-linear Simplex is employed. This process is continued till the final correct yield line pattern is achieved; which can automatically get Veneratedd on the screen using the facility of PLOT-Be. The GYL- O also consists of f. sign subroutine which designs the regular sl ahs by limit state method on the basis of calculated bending moment. coefficients.