Structural concrete designers nowadays distinguish between B-regions (named after Bernoulli
beam theory) and D-regions (D standing for 'disturbed'). They are all familiar with B-regions
but less acquainted with the expertise required for D-regions. To design D-regions the
Strut-and-Tie Model (STM) is usually applied a model laid down worldwide in structural codes
of practice. The Stringer-Panel Model (SPM) recommended here is a companion method to the STM
with the advantage of being suitable for different load cases and reversed loading. This being
so the SPM is suitable for linear-elastic analyses where durability is a key consideration
but also suits structural design for contexts of cyclical seismic activity. Finally this book
sets out how structural engineers who prefer the STM can nevertheless apply the SPM to
determine a proper strut-and-tie model.
