LOAD AND RESISTANCE FACTOR DESIGN (LRFD)

LOAD AND RESISTANCE FACTOR DESIGN (LRFD)

ABSTRACT

Developing guidelines for reliability-based design of structures / structural members is a topic of current research interest. Load and resistance factor design [LFRD] format is a popularly used reliability based design .The Indian Standard code IS: 800- 1984 uses allowable stress approach, which limits the usefulness of the material up to a load, at which the maximum stress in extreme fiber reaches its yield value and also gives higher sections which are uneconomical. Also this method does not take into account of the material strength beyond the allowable stress and also variations in dead and live loads. For designing a practically possible and economically feasible structure approach with partial load and resistance factors become essential .Therefore the LFRD approach takes this advantage. Load and resistance factor design [LRFD] method, owing to its strong statistical base will ensure uniform level of reliability in designs as well as low cost.
This paper presents an elaborate AISC- LFRD procedure for steel beam and a column section proposed with Indian Standard. This paper focuses the cost benefit of the proposed LRFD over the conventional elastic method.