Theoretical and empirical approaches to the problem of combined bending and torsion have been proposed by various investigators, notably Lessigl,2,3, Chinenkov4, Yudin5, Gesund6,7. Although a full understanding of the mechanism of failure does not exist,
considerable advances have been made in recent years. The most elaborate approach which correlates theory with the mechanism of failure was by Lessig and the present investigation was carried out to study the behaviour and the mechanism of failure of hollow reinforced concrete beams under combined loading. A simplified theoretical approach has been evolved which predicts the strength of reinforced concrete beams fairly accurately.
Professor R.H. Evans and S. Sarkar