Abstract

Undergraduate engineers at Cambridge are all taught how to use plasticity theory and yield-line calculations to predict the load that ductile slabs can carry before they collapses in flexure. The method works well for simple exam questions, and it can produce much more accurate results than the conservative elastic methods often used by practicing engineers. However, when using yield line analysis on real reinforced concrete slabs with complex geometries, engineers are often concerned about the possibility of producing unsafe results. This talk presents a new safe and accurate method for performing plastic flexural analysis on real slabs.

The new method retains the simplicity and rigour of traditional plastic analysis whilst harnessing modern computational techniques to produce highly accurate solutions. Unlike previous plastic methods, close lower and upper bounds to the theoretical plastic collapse load are identified. Unlike many other computational methods, the results can be easily understood and checked by hand.