YIELD-LINE ANALYSIS BY SEQUENTIAL LINEAR-PROGRAMMING

The rigid-plastic yield-line analysis of isotropically reinforced concrete slabs under uniformly distributed loading is developed as the lower bound form of a linear programming formulation. The analysis is extended to consider geometric variation of chosen yield-line patterns by the technique of sequential linear programming. Linearized geometric sensitivities for use with the sequential process are developed analytically. The geometric Variation algorithm is shown to be effective for the determination of collapse loads and modes, although the evaluation of collapse geometries is often of a lower order of accuracy than that of collapse load determination. Direct generation of critical collapse modes is not generally possible although an indication of more significant modes may be obtainable in some instances.